1985 Limited Edition and 1986 SE-i Fuel Injection Motorcycles

Dave0430 is correct in where the MAP connection has to be. To use a sensor in the plenum area, it would have to be a mass air flow sensor, and probably before the carburetor, or ITB if fitted. More challenging install.

Difficult at times to use the correct wording when trying to explain the issue. Being the author is harder than being the editor.

If there is an issue with how I describe what is being discussed in a post, let me know and I will correct it. Dave0430's short post on where you have to connect the MAP sensor to get engine manifold vacuum was what I wanted to mention, but could find the words at the time.

Cheers

Going to be off line for a bit, will check the forums as I always do, but won't be posting. Have other projects that need to be attended to. As I have mentioned, these posts are to stimulate the imagination regarding the art of the possibility regarding an EFI installation, not as a definitive guide. Lots of information here to ponder for the next while.

Cheers

Well ****

Well **** - back at it again. Have had the GW out for trials, ECU engine tune coming together.

Was queried in a different thread about ignition timing. For the 1000/1100 rather straight forward - a distributor system, for the 1200 GWs an electronic ignition timing with an ignition control module (ICU).

Let's go back a few years regarding the distributor ignition system. Points/condenser mechanical advance with weights and a vacuum advance. Many mods were done, changing the mechanical weight springs, lighter/stronger spring tension, even disabling the mechanical advance weights, but keeping the vacuum advance. All this to gain some engine performance. The reality is that we did achieve our aim from these mods, but we never really achieved a significantly better ignition timing curve that covered the complete spectrum of engine performance up to wide open throttle (WOT).

We could read the spark plugs for an indication of engine performance. Reading spark plugs properly gives indications of correct ignition timing, and correct air-fuel mixture.

There have been many aftermarket units developed and used to replace the points/condenser from an OEM, but this only changed the maintenance of the distributor ignition system, no longer reliant on having to adjust the points every so often from normal wear. The OEM timing was still in play, not much wiggle room for adjusting the ignition timing profile.

What are your options with a distributor ignition system? Upgrade to an electronic distributor ignition system. Keep with the same, install an aftermarket electronic fuel injection system. Replace fuel and ignition with a full EFI system.

Early EFI systems did a better job of controlling ignition timing. A person could if so inclined, delve into the ECU and modify the ignition timing profile. This generally required a good understanding of the programming language, having access to the engine tune program and having the equipment to flash the EPROM where the engine tune was residing. You may have had to flash a new EPROM and replace the old. All very specialized.

Honda had the first FI system ECU that was quite similar to the new map based ECUs. It did everything that the new aftermarket ECUs have the ability to do, and with several unique features. This was back in the early '80s at the onset of FI in motorcycles. The disadvantage of these early FI systems is that generally you had no access to the engine tune, there was no instrumentation/tuning tools available to the operator, maybe not even the Honda dealerships.

Honda GWs had two timing marks. "T1" for crank and camshaft alignment and setting #1 cylinder iston at TDC. The second was "F1" for idle timing of approximately 10 degrees BTDC. Other wise no ability to adjust the timing outside these two parameters. The ICU used on the 1200 carb model GWs was a definite upgrade to the ignition system, but still no ability to adjust the engine timing profile.

The benefit of electronic engine ignition timing using an ignition control unit, or partial features in an EFI ECU, is the ability to calibrate the various map(s) that affect engine ignition timing, and use the other ECU features that enhance the engine ignition timing.

I have mentioned previously that a carb engine with a distributor style ignition system does not use the various engine parameters that can enhance engine ignition timing sculpting as engine coolant (CLT) and inlet air temperature (IAT), battery voltage compensation, barometric corrections to name a few.

What is the reason to chase engine ignition timing. Engine performance and fuel economy are the two. Race and track requirements will be different than that for street. A lot of time can be spent trying to dial in a carbureted engine with a distributor style ignition timing system. Benefit is that you don't need any specialized tools, there is a significant amount of on-line information to be had, and you get to do it yourself with a minimal tool set.

Changing spark plugs from the OEM recommendation to the newer iridium style or similar may provide some increase in engine performance, but most of us laymen will not notice the difference. This is mentioned in quite a few on-line articles, save your money. It's like burning premium gasoline when regular octane fuel is recommended. Many times it's perception, not from empirical data.

A carbureted engine draws fuel from the carburetor into the engine cylinders based on air velocity, engine manifold pressure. The carburetor does not take into account any other engine operating parameters.

The fuel going into the cylinder is metered by the carb fuel jets. An OEM spends a lot of time, resources and money to get the carburetor fuel jetting and ignition timing profile to a point where the engine at idle and up to WOT manages to have an air-fuel mixture to achieve an air-fuel ratio (AFR) as close to 14.7:1 as possible at engine idle. This AFR changes as the engine is operated, as the distributor mechanical and vacuum advance kicks in.

The general expectation is that the greater the engine RPM and engine load, the air-fuel mixture would be calibrated for a rich fuel condition to safeguard the engine. This is achieved by having a fuel rich condition at idle that will equate to a good air-fuel mixture at powers up to WOT. This is a reasonable expectation because the engine fuelling and ignition timing is set for engine idle speed. If you were to change this so that you operate the engine in a lean fuel condition at idle, you will probably operate the engine up to WOT without sufficient fuel to achieve a good AFR and to safeguard the engine.

There are a lot of threads regarding ignition timing and ignition systems as well as why are my spark plugs fouling. Interesting reading. Carburetor jetting can be an issue, but so is ignition timing. In a carb/distributor ignition timing systems, correct engine timing is required for the amount of fuel being drawn into each cylinder.

Keeping/maintaining the OEM design specifications is the best way to ensure that the engine performance and fuel economy will be the best it can be. This is based on the fuel burn rate such that all fuel at whatever engine RPM and load the motorcycle is being operated, is fully combusted at around 10 to 15 degrees ATDC. This is the optimum ignition timing for best engine performance and fuel economy.

If the fuel is not completely combusted at this optimum ignition timing, the excess fuel will continue to burn in the engine cylinder resulting in spark plugs fouling, and the engine is being used as a heat sink for the excess heat being generated resulting in higher engine coolant temperatures. Installing larger carb fuel jets than recommended by the OEM can result in this condition.

If the fuel is fully combusted before the 10 to 15 degrees ATDC will affect engine performance and fuel economy as well. The fuel burn will not culminate at the correct time to assist the downward motion of the piston during the power stroke, it runs out of "omph". Plugs may not foul, engine may operate a bit cooler, but you may also notice engine "knock" during engine operation.

Time for a new post.

These posts are my understanding of a topic. The information is out there for you to research if so inclined. I'm not asking, nor do I expect everyone to agree with me. On with part two.

Ignition timing is as expected, an integral part of the equation. You want sufficient ignition timing to allow the lean fuel condition at idle to completely combust by the time the cylinder in question hits the 10 to 15 degrees ATDC, without inducing engine knock. I mention that there is a lean fuel condition at engine idle RPM because the OEM tries to achieve an air-fuel mixture that equates to the stoichiometric ratio of 14.7:1. Once the engine idle ignition timing is set for this AFR, the rest happens because of mechanical and vacuum ignition timing as per the OEM design, and the AFR up to WOT will be what it is. Unfortunately, we have no access to this data unless you want to utilize the services of a shop with a dynamometer and do a lot of experimentation.

The OEM generally specifies when full engine timing is achieved, but this should be done under load, not when the engine is in neutral and the engine RPM is increased to the required RPM. Once past this point, the ignition timing is fixed at this value.

The ICU of the carbureted 1200 GWs is an upgrade to the distributor style ignition, but it is a PnP unit that you cannot change the ignition timing profile. You may consider the ICU to be a disadvantage to you the owner. A distributor ignition timing system with points and condenser can be made to work so you can get home. If an ICU fails, call a two truck.

We live in an electronic world. Everything is a compromise. Do you intend to keep the bike for a while, is it a weekend rider or a daily rider, what are your requirements.

There are a significant number of fuel only, ignition only projects as well as full EFI. Fuel only or ignition only installs are generally used as a learning opportunity that can be morphed into a full EFI install. There are a lot of bench projects that come to fruition and may result in an EFI installation, but there are a lot that do not. A complete EFI install is not for the faint of heart. I mention this because of the commitment needed to bring projects such as these to fruition.

An EFI mantra is that you give the engine what it wants regarding fuel and ignition timing. Research indicates that this can and will possibly differ from the OEM design. The OEM cobbles together EFI components and makes these components work. This may not be true for us laymen who enter the EFI arena.

This EFI mantra may differ from the OEM FI system design. Timing may not be what you expect to see. The OEM has the engine idle ignition timing at 10 degrees BTDC. Your EFI installation, or ignition only installation, may have the idle ignition timing at 18 degrees BTDC to achieve an AFR in the range of 14.7:1, maybe more.

There is no GW engine ignition timing curve available to use, and if there was/is, this ignition timing curve should be used only as a starting point, not the end result.

Tuning an EFI install requires you get the fuel component under control, dialled in first. You want the air-fuel mixture at idle to be such that you are not fouling plugs, and are not asphyxiating yourself.

The more accurate the air-fuel mixture at any point in the engine operating profile, the easier it will be to get a good engine tune. This requires experimentation and as the engine tune develops because of this, resulting in the engine performance and fuel economy improving, you use ignition timing to fine tune the engine tune. Engine ignition timing will dial in the fuel burn time such that the amount of fuel being drawn into the engine cylinder(s) is fully combusted at the optimum engine timing of 10 to 15 degrees BTDC ensuring the engine develops maximum power and fuel economy. The philosophy is fuel, timing, rinse and repeat.

When you do not have a fuel component involved, the ignition only install will be more challenging. You will not be able to balance the system using fuel and ignition, but the ignition only install will be a significant upgrade.

Engine ignition timing is affected by many factors. Camshaft and intake/exhaust valve changes, as well as exhaust system changes to mention a few. An ignition timing install allows you to adjust the ignition timing profile to accept the new changes in components. Without having the ability to recalibrate the ignition timing to accommodate these changes, your expectations regarding the changes may not come to fruition. I submit that most of us would not notice a change in performance from the original OEM installation, but maybe a change in fuel economy.

More to follow.

Well **** (tribute to Dusterdude’s eloquent vocabulary) – it’s philosophy time.

It’s like being in school during your teen years and studying history, why, because the curriculum made you. Never liked history in school, but find it fascinating today. The missing link IMO was context, you had no life experiences to relate the course to.

I treat my car as if I was in school, I open the door, key in, start engine, put it in “D” for “ditch” and go. Could not care less about the workings as long as it does, and the final course grade for doing just this is, of course, 100 percent – I passed.

My thread(s) on fuel injection, modifications to the motorcycle and such are exactly the same with a slight twist, I have and so do the readers, life and work skills that allow us to better understand and do the work.

My ’85 1200 GW FI Model is my school and school project. I want to know how things work. Think about the Roman aqueducts and those regal archways supporting the structure. Why are they at a specific height, easy to explain, if the arches were higher, they would collapse – trial and error. Good engineering practice back in the day.

This is similar to the various posts I have made regarding engine ignition timing, fuel system requirements, coil upgrade/replacement, fuel injectors, carburetor fuel jetting, and such. We are great backyard engineers and tend to second guess the engineers that designed the various systems. We swap out various components because “it works”, not because we took the time to experiment and produce some empirical data that would justify a specific change (some people do) – coils are a good example.

Coil dwell times are critical to the operation of an engine. Internal coil design, wire size specifically, impacts on the coil operation. The time required to “fully charge” a coil before the coil charge is released through the spark plug is key to the operation of the engine. Too little coil dwell time, weak spark. Too much dwell time, coil failure and burnout.

Reminds me of the days when we spent inordinate amounts of our cash to “soup” up our cars, turn them into “sleepers”, so that we could emulate those cars that did burnouts at the track – we used local roads. Road racing without the nicety of spotters looking for the local gendarme. Did we spend any time researching the requirement, getting the correct replacement part(s) for the mod, I submit most of us did not. Old school backyard seat-of-the-pants engineering, but it worked.

Fast forward to today. Not much has changed since those heady days of our youth (speaking for us old guys). We do and did modifications, parts exchange because what we are looking for has or does work with no detrimental effects.

Now for the kicker, do you want better, not just good enough? The only way to make this happen, is to modernize your ride involving a makeover of the fuel and engine ignition timing systems.

You will not get more HP from this – maybe but don’t expect too much, but you will get better engine operating performance and fuel economy. You will need to go back to the school of hard knocks to learn about the new systems available, component interaction, how the outside environment contributes to a new installation, how your modernization affects the engine to name a few.

Philosophically, this can be mind bending. There is so much information available, opinion are never ending. You have to sift through this and take from it what you need and understand. It’s like in school, a person who finished a course with a 90 percent average should have acquired a better understanding of the subject than a person with a 70 percent average, not always the case but you would think so. I have never seen a diploma, certificate, degree with a course percentage on it. After the fact, we are all equals, right?

Philosophy aside, if you like this story and it is a story, continue following – I appreciate it. This story is my opinion and understanding of the topic, nothing more – nothing less.

A thread like this is similar to the news. You have to watch various networks to get a good picture of what is really happening. Watching one and only one does not present enough information for you to make a very informed decision on the issue. Discussions over coffee will help as well, a different perspective. My web browser bookmarks is full of various on-line sites regarding different articles that have been helpful in putting a thread like mine together.

Where to from here? Review of thread information, choose the next logical topic, and continue.

Thanks for reading.

Cheers

Having discussed ignition timing in good detail, next item up for discussion is the battery. I can mention from experience that once a battery fails, a fuel injected motorcycle will not operate, no bump starts as well. You may get lucky with a bump start, but generally the bike is dead on the roadside.

Most OEMs, car or otherwise, have designed the starting/ignition system and normal engine operation based on the combined usage of battery and alternator. The battery still has only three requirements regardless of where it is installed; to start the vehicle, absorb system voltage spikes, and supplement the alternator if required. Many OEMs, if not all do not recommend operating your vehicle without a battery installed. There is a good possibility that you could damage the electrical system electronic components if you operate your vehicle without a battery.

A good battery will, after having been used, accept a charge up to a 100 state of charge quickly, then settle into a maintenance mode accepting a trickle charge, and all power being developed minus the trickle charge will go to operating the electrical system.

The ‘85/’86 1200 GW FI Models have a stator that will accommodate an electrical system load of approximately 35 amps. The smallest automotive alternators are approximately 45 amps. The automotive alternators have a regulator/rectifier system that allows adequate system voltage and battery charging at approximately1000 RPM.

I mention the above because consistent, clean power generation is a requirement for an EFI system. An EFI system can accommodate small electrical system voltage swings, but nothing of any great magnitude.

When an AGM or wet cell lead acid battery starts to fail, or has failed, it will cause the alternator output to be greater than the alternator RR reference voltage of approximately 14.2 VDC. This affects the electrical system voltage in that the battery will “rob” much needed power from the system to try and maintain a 100 percent state of charge – BTDT. A failing AGM or wet cell lead acid battery will normally let you get home, not always, but normally.

A failing/failed lithium-ion battery is not as forgiving. It will degrade and not accept a charge from the electrical system. As the lithium-ion battery starts to fail, you will notice small changes to the FI system operation. When it fails completely, at approximately 12.4 VDC, the battery will shut down as well as the motorcycle. Had this happen to me on a road trial.

We owners abuse batteries. We let batteries lay idle for months on end without charging them once a month, or installing a trickle charger. Batteries sulfate over time because of this. This sulphate is between the internal battery plates insulating the plates and restricting current flow between these plates. If there is enough sulphation, the battery cell affected will fail, starting a chain reaction.

We owners try and wring every ounce of power out of the batteries because of maintenance expense. Not a good idea with an FI controlled engine system, or a carbureted engine system.

Motorcycle batteries are not as robust as the batteries in our cars/trucks because of size. You can have these smaller batteries last for quite a while, but a maintenance system must be used. I know people who have had these smaller batteries last for up to 10 years, but when not in use, a trickle charger is used, and if in the colder climates – inside a heated space with a trickle charger attached. My recommendation is to replace your motorcycle battery regardless if it is a carbureted or FI motorcycle every 3-4 years, small price to pay for peace of mind operation.

The takeaway here is that the charging/electrical system must be in good condition and working well. All components in these systems must also be in good working order. Connectors, grounds and grounding points need attention. Ground connection(s) can be the bane of your existence.

I have probably mentioned the above in other post(s), but it is always good to refresh our memories on a topic.

A quick and dirty follow on post. Thinking I've covered most, if not all, aspects of an EFI aftermarket ignition control system to provide a reader with some food for thought. What is remaining is the design and installation.

Most Speeduino and Speeduino clone ECUs have the same basic connections. Some of these ECUs have additional features already installed such as barometric sensors, tachometer outputs and such. Most of these ECUs have these extra features available, but there may be some circuit design installation required.

The Speeduino ECU interface board, v0.4.4, that I am presently using can have a barometric and tachometer function available for use as long as you are willing to read and understand the requirement, and install the required circuit. Remember, the ECU interface board is a conduit between the controller, in this case an Arduino Mega 2560, and the engine operating system(s). When you modify the interface board to provide these extra features, you are creating a circuit to connect the controller and the engine program, through the interface board to the external engine operating system(s).

I'm also thinking that a post or two regarding the design/development of a Speeduino interface board may be in order. There's a significant number of circuits imbedded in the interface board with the respective components mounted on the interface board.

The Speeduino Project ECU is an open source project and it is expected that when this information is used, the author of the new information/design will post the information on-line for all to view and if wanted, to use.

Something to ponder.

Cheers

Going to start a new thread regarding the Speeduino ECU interface PCBs. This is the thread web site: https://classicgoldwings.com/threads/speeduino-ecu-pcbs.15594/

Cheers

I have been pondering the use of a single carb conversion (SCC) for the older GWs, and would like to discuss this issue as it relates to EFI ignition only. This post is for discussion, to think about why this modification is done and how it relates to an EFI ignition only installation. I have done many mods to cars and my motorcycles over the years without worrying about the why and what may be the result, mostly because I could and I wanted something different. This post is in no way meant to discourage anyone from doing an SCC.

The SCC is an accepted modification for a variety of reasons, but what is the basis for this. I have been thinking about a lot of modifications and why the modification is done such as the external alternator mod (Poorboy). The Poorboy mod is a good upgrade, easier to maintain and fix if the alternator fails, and stator angst is removed from the equation.

Doing an SCC is just as good. Only one carb to calibrate, parts for the chosen carb may be more widely available. The final reason for anything we do to our older GWs is because we can. Keeps the creative juices flowing.

Let’s compare design aspects from a layman’s perspective, IMO perspective.

OEM design, 4 carbs each based solely on the fuel requirement for one cylinder using the absolute manifold pressure from the respective cylinder to draw the air-fuel mixture into the cylinder.

How does this relate to the EFI ignition only installation? If everything is working properly, the ignition system is designed to provide ignition timing, coil discharge, and fuel burn time to adequately combust all fuel drawn into the engine cylinder(s) for optimum engine performance and fuel economy over the engine operating range. Location of the carbs reduces “wall wetting”/fuel puddling (minimum fuel travel to the cylinders so that the designed fuel requirement is used, not much left in the runners to the engine cylinder(s). The fuel will evaporate/atomize sooner and much better than with the SCC because of the short fuel travel to the engine cylinder. Lean and rich fuel operating conditions are minimized with the OEM design.

The ignition coil design is to provide adequate coil discharge, timed to fully combust the cylinder fuel charge to achieve as close as possible the air-fuel ratio of 14.7:1 for optimum engine performance and fuel economy.

Enter the SCC modification. One source of fuel for four cylinders. Long intake runner(s) to the respective cylinders resulting in “wall wetting”/fuel puddling especially in colder climates during initial engine start. Unknown lean/rich fuel operating conditions on engine start and during operation.

There are fabrication issue as well. What is the intake manifold design going to be, throttle cables, choke cable, and such. There are several examples in the forums of intake manifolds that can be used, and how to fabricate these. The SCC forum threads generally detail how the intake design is done.

Fuel distribution is something to consider. You are drawing fuel out of the carburetor into the intake plenum. The intake plenum may be warm when the engine has reached normal engine operating temperature assisting the air-fuel mixture atomization, but not so on initial engine start. Fuel will not atomize well and the engine requires additional fuel to minimize a lean air-fuel mixture. Engine cylinder absolute manifold pressure should be approximately the same for each cylinder, if not there will be an uneven distribution of fuel resulting in lean/rich air-fuel mixtures depending on the engine cylinder.

Older cars needed warm up time to operate. Without this warm up period, the engine did not receive the correct air-fuel mixture and the engine would stall. The same issue happens with an older GW with a SCC.

You can design your SCC system with an engine coolant system. This system would only be used when there is the possibility of carburetor icing, not for normal engine operation when icing conditions should not happen. Sounds like the aviation industry but the premise is the same, once the engine is at normal operating temperature, there is sufficient heat generated to minimize/alleviate the possibility of carburetor icing.

EFI engines do not require additional “carb” heat, not prone to icing. Fuel is injected just upstream of the intake valve that heats up faster than other areas of the engine, and evaporation/atomization of the air-fuel mixture occurs as the fuel is drawn into the cylinder.

Ignition timing is limited on these older GWs. When issues arise from an SCC such as engine pinging, fuel detonation, pre-ignition and such there are some remedies available such as changing the spark plug heat range, using premium fuel – higher octane rating, pre-ignition from carbon build up on exhaust valves. These thoughts are no different from thoughts on engine operating issues that comes to the fore and the first thought is about the PG sensors, or other sensors are bad, what about the coils, and the list goes on.

Automotive distributor timing is more flexible. Timing can be better “dialed” in to accommodate issues from carb replacements. Honda has timing marks, scribed on the engine crankshaft, but these are only for crank and camshaft alignment and engine idle. To make changes to the ignition timing of a car engine, it can be done with the engine operating, and there are timing marks up to the maximum ignition timing as designed by the OEM. This is not possible with a GW engine in the original OEM configuration.

I have recently read a forum thread where an SCC was done on a GL1500. The result of this conversion was that when the planets were aligned, it worked well, but if not, the new owner is having engine operating issues, more of the latter than the former. I have found one forum thread where a GL1500 was converted to EFI, but the engine tuning issues were significant and the owner reverted back to the original OEM carb design.

This post is about the ignition system being one part of the overall design. An overall system perspective must be taken into account when doing a project such as an EFI ignition only installation. It’s always “if I do this, what else may be affected, or how is this singular change going to work if I don’t do any other change”.

I’ll end this post by mentioning that what you read and see on-line – including the information I post, information from friends/peers, and off-line literature such as manuals, is a starting point and not the end result, there are so many different variables. You will have to, maybe not, modify/calibrate whatever you are doing to customize the project you are doing so that it operates as you expect it to.

Thanks for reading, hopefully I have provided some food for thought.

Cheers

Slow progress day, so I thought I’d do a post about the ECU evolution; from the original OEM CFI ECU to the one I will be using going forward.

The original ECU enclosure/case measured 6 ¼”W by 6 3/4”L by 1 ¼”H. Had two PCBs and operated a “fully” featured EFI system. Had a barometric sensor as well – small black box in third picture. The OEM did a very good job of making the CFI system work well, and without an O2 sensor. This ECU had two camshaft sensors, two PB (MAP) sensors, a diagnostic program for the CFI system components, as well as other attributes. Used tables (maps) for fuelling, and ignition timing. Had a fail-safe fuelling program such that if the PB (MAP) sensors failed, the ECU switched to an Alpha-n fuelling profile. Well ahead of its time.



Fast forward some 30 odd years. The new crop of aftermarket ECUs that do exactly the same as the original, if not more, are significantly smaller. The new aftermarket ECUs only use one MAP and camshaft sensor. There is no diagnostic program unless you install as an add-on feature. Not all aftermarket ECUs have an installed barometric sensor, or dedicated fuel pump and tach connections. The following pictures show an evolution of an aftermarket ECU compared to the original OEM CFI ECU. I will be showcasing the Speeduino ECUs as that is what I have.

The first pictures shows the difference in size of the interface, PCB, boards. From left to right, Spark Gap X4 fully featured Speeduino ECU, comes with case and OEM wiring harness connector. The next is a Speeduino ECU connected to the OEM CFI ECU enclosure/case connector. The third is the original OEM CFI ECU PCBs:



The next couple of pictures illustrate the difference in size of the original OEM CFI ECU enclosure, and with a Speeduino ECU in the same case. Case and microprocessor for the Speeduino depicted in the OEM CFI ECU enclosure/case are purchase separately. The third picture is the latest Speeduino ECU that I will be using, a Spark Gap X4 from openlogicefi, notice the size of this ECU, no bigger than a deck of cards and height is only two decks of cards high:



These ECUs control the engine FI system the same way. Using tables and various component settings/parameters to ensure good engine performance and fuel economy. The main difference between the OEM CFI ECU and the aftermarket ECUs is that you are able to modify/adjust/calibrate the engine tune providing you have the appropriate tuning software (and are willing to learn the engine tuning process/procedure), you cannot with the original ECU.

There are differences, but these are specific to the ECU in question. The difference between the Speeduino ECU that I will be using going forward and the original Speeduino ECU I purchased in 2018, is there is an installed barometric sensor, a dedicated fuel pump and tach output terminal to name a couple.

The size difference is very apparent when these ECUs are placed side by each. The barometric sensor installed on the OEM CFI ECU PCB is significantly larger than those used today. The first picture shows the barometric sensor used in the original ECU – the large black box in the picture. The second picture shows the size difference between the first Speeduino I purchased and the one used on the Spark Gap X4. From big to small:



The “brains” of the original ECU was burned into eprom chips that were installed into the ECU PCBs. These have been replaced with various types of microprocessors that the user can program at will with the appropriate tuning software. Eproms had to be removed from the PCB, and specialized tools/test equipment were used to program/reprogram as required. The first picture shows the 2 rectangular eprom chips used in the original ECU. The next picture shows the micro processing chips used in the Speeduino ECUs, the smaller microprocessor (black) is the same as the blue Arduino, just smaller:



Honda does not give up its design and engine tuning specifications willingly, mostly not at all. This includes the newer 1800 GWs.

Just some lazy afternoon rambling. Time to get back to the GW, slow progress but worth it.

18n gauge wire arrived today. Going to be a nice addition to the project. Striped wire makes for a good install in that you can differentiate from the standard solid colours that are predominantly used, and the OEM wiring as well.

Had made a wiring schematic with the last time being in January. Spect the last two days finding the schematics that I did. Have to do some homework to determine how to link new schematic sheets to the master, and redo the symbol library - lost in the ether world. Using KiCad.

Updated wiring schematic:

More to follow.

Slow day at the office. Have been working on the wiring schematic(s) for this project. Rebuilding the symbol library. Think I have mentioned I am using KiCad, and open source application. IMHO, having an accurate schematic set is just as important as installing and making the EFI system work. Will be beneficial later on when I will want to sell the bike, that day will come. Takes a bit of time to produce a schematic that is accurate and detailed.

This schematic shows three of the mods I have done since I purchased the bike in 2015. Sidecar Bob has the never ending "Eccels" project, I have the never ending GW project, don't have a name for the GW:

Any electrical engineers reading? Question if so, the original CFI design has the tach signal based on numbers 1 and 3 fuel injectors (paired injectors). The signal is fed into the travel computer and I guesstimate that there is a circuit that converts the fuel injector signal to a useful digital signal for the dash Tach and the fuel management system. I have sequential fuel, and only one fuel injector signal is sent to the travel computer. Thinking connecting a second fuel injector in parallel with #1 for load into the circuit to determine the way ahead. It has been mentioned that an automotive relay can also be used. Apparently it is the flyback part of the fuel injector signal that initiates the proper tach pulse. This is the schematic using a relay coil:

The tach stopped working at the onset of this project when I initially was using wasted spark and paired injection - all other functions/features of the travel computer work. Not a significant issue at this time as I ride with a tablet that has an RPM indication.

The output from the Speeduino ECU has been verified as being a 5 volt signal. Will connect this signal to the dash, by passing the travel computer to start. If there is no tach, have a schematic that can up the signal voltage to 12 VDC. Thinking out loud and brainstorming.

More to follow. Cheers

Question to the collective and my loyal followers.

On the more serious side of this thread by this author. Thoughts on doing a thread on the tuning software, what is available, the interrelationships between the various settings, and what it means for you the user. I have done this for myself in an EFI document because the tuning software, Tuner Studio (TS), is quite comprehensive. The data analysis software, MegaLogViewer (MLV), goes hand in hand with this. If you would like to dive into the tuning software and data analysis world, let me know. I do enjoy pontificating about anything EFI, you may not have noticed,.

As I mentioned, let me know. Cheers

I have additional thoughts on a plug-and-play (PnP) Speeduino ECU that would fit in the OEM ECU enclosure. The "strawman" that I have considered is using the Speeduino interface board v0.4.4 as the basis for this PnP ECU, with a few modifications such as dedicated tach and fuel pump connections (maybe a few others), on-board barometric sensor. The Speeduino v0.4.4 interface board is apparently the "go to" board design for quite a few of the Speeduino interface board clones.

There are approximately 8 unused OEM wiring harness connector pins so there is adequate room for expansion. Maybe have the Arduino processor included in the board footprint eliminating the need for an Arduino Mega 2560 or Arduino Mega Pro shield. The new size of the interface board would allow for a significant number of new features/circuits. Finding an ECU connector that is oriented the same as the original ECU connector could be a challenge.

I have been browsing the Speeduino forum to determine if a PnP Speeduino ECU clone for a specific vehicle comes as a PnP unit that is preconfigured with an appropriate engine tune. My research indicates that the user would have to populate the new ECU with the various settings, and such and start tuning the engine from bottom up.

The VE (fuel), spark (ignition timing) and AFR tables would need to be populated with appropriate cell values.

From this, I deduce that a PnP ECU is designed to connect to the original OEM wiring harness with no additional work to be done except doing the engine tune. In simpler terms, remove the old PCBs, and install the new PnP ECU in the same spot, then get on with the engine tune.

I'll do more research on this and report back what I find. Will have to start a new thread. Cheers

My loyal followers have decided. I will engage the creative juices and start to develop thoughts on the above two topics. Have to put the GW on hold for a few days. The 2008 Ford Escape requires my attention regarding oil leaks. These vehicles historically leak oil, not all but quite a few. Valve cover and oil pan gaskets. Valve covers not too bad, but oil pan needs the exhaust dropped. may have to get it to a shop so I don't break any bolts. Cheers

Took the Ford to the local garage for the oil pan gasket yesterday. Dropped it of around 11:30 AM got it back around 4:00 PM. Wasn't going to test the exhaust bolt gods; however, it was a $450.00 CDN bill all in using cash. Using plastic would have been another $60.00 CDN. Gasket was $130.00 CDN, twice the price I could get it for and the same manufacturer, Fel-Pro. I will do the valve cover myself. Been a long time since I have had to use a service garage for work, but no snapped exhaust bolts. Lying on a garage floor to do work is no fun. Gotta know when to hold 'em, know when to fold 'em. Valve covers starting this morning. PCV and plugs as well. Cheers

Let's not forget it's a long way down, and twice as much coming getting up!

Mentioned I changed the OEM wiring harness connector to the Spark Gap X4 connector. Changed the fuel injector layout to paired fuel injectors, kept sequential ignition. Connected the Spark Gap X4 to the system, no joy. No spark or fuel and no crank or cam signal.

Contacted the company. Sent a schematic of the Hall Effect sensor connections for a "pull-up"resistor circuit.

The crank and cam Hall Effect circuit is a "pul-down" resistor circuit. The Hall Effect sensors I use require a "pull-up" resistor circuit. These new ECU board designs don't have a lot of non-integrated components like the oder boards. The jumpers that determine whether the crank/cam circuits are using VR or Hall Effect sensors are visible and stand out - pardon the pun. The J1 and J2 jumpers are extremely small and are just there, unobtrusive.

The fix to change from a"pull-down" resistor circuit to a "pull-up" resistor circuit is to bridge close jumpers 1/2, both if using crank and cam sensors. This is the schematic of the jumpers in question:


You can see in the schematic thatJP2 is OPEN. A small bit of solder on the board CLOSES JP2. The cam circuit is identical. Had to use a magnifying glass for this, and not because I'm old.

It is a good learning experience regarding reading and understanding a circuit used in a PCB.

Cheers