1985 Limited Edition 2022 Work Period

Looked at availability of intake/exhaust valves on line. Have found intake valves across the pond and only one exhaust valve across the pond. More looking to do.

Will check with dealer on Tuesday. Not an inexpensive proposition.

Way ahead right now is to change left side cylinder head, change out fuel injectors and Tw sensor. Remove front fairing to do minor maintenance on steering stem, some wiring - always better to work with the front fairing off, and clean/paint the air shield under the triple tree.

Onwards and upwards as I've heard on occasion.

I've not checked for 1200 valves, but 1000 valves are available from Parts-n-More.

Ding some investigative work and changes. Have swapped out the injectors, back to the original. Have to wait for a good road test to determine if anything has changed.

Ticking noise is definitely from the left head, and #2 cylinder. Changed the 1 mm intake shim to a 0.69 mm shim. Ticking noise got more pronounced and from initial start. To me this should not be, but will work on it. The the engine cools a bit, thinking of using the original 1 mm shim with the 0.69 mm shim. Can't hurt to try.

The initial shim measurements I took are:

Shim requirements for intake/exhaust - read in three columns:

Intake - mm/Exhaust - mm/Shims

11.5-10.5/13.5-12.5/2
10.5-9.5/12.5-11.5/1
9.5-8.5/11.5-10.5/0

The readings are:

#1 intake - 10.5 mm OEM had 2 shims - borderline between 2 and 1 shim requirement - change to 1 shim
#1 exhaust - 11.9 mm OEM 1 shim - no change
#2 intake - 9.17 mm OEM 1 shim - change to 0 shim
#2 exhaust - 12.2 mm OEM 1 shim - no change
#3 intake - 10.7 mm OEM 2 shim - no change
#3 exhaust - 11.9 mm OEM 1 shim - no change
#4 intake - 10.2 mm OEM 1 shim - no change
#4 exhaust - 12.09 mm OEM 1 shim no change

#1 intake got a change, but there is no ticking that I can hear on the right side, using one of those stethoscopes.

Took new compression readings with the 0.69 shim installed:

#1 - 160 PSI
#3 - 165 PSI
#2 - 160 PSI
#4 - 155 PSI

Pretty good I'd say.

Checked for spark. When removing the plug caps on numbers 1/3/4 cylinders, engine wants to stall. Removing #2 pug cap and the engine does slow down, but does not want to stall.

Tw sensor still on the agenda.

More to follow.

Had to go out after dinner and continue with the ticking noise investigation. Had a rush of @#$% to the brain and thought that I'd increase the shim stack on #2 intake valve from 0.69 mm to 1.69 mm - add an OEM Honda shim, these are all 1 mm thick. Did this and the ticking noise got louder, made sense. Did another compression test of numbers 2 and 4 only, not working on the right side. Compression readings good again, 160/165 respectively, using the same compression gauge so all is going well. I can now mention that the engine has 160ish PSI compression all round.

Thought about the initial shim change and #2 exhaust was adjusted as well. Went from 2 shims to one. Adjusted #2 exhaust shim stack, added a 0.69 mm shim to the 1.0 mm Honda shim. Started engine and no ticking noise, even after letting the engine operate to 7 bars on the temp gauge and manually adjusting the RPM to 2000.

Not jumping for joy yet, but pleasantly surprised with the results, heading in the right direction. Tomorrow will be a telling day, if the results are the same, time for a road test.

Had to think about this because it seems counterintuitive to me. Adding shims moves the shim nut out and lets the hydraulic lifter lengthen. Before doing this, I would surmise that the lifter was not at an optimal length and was acting more like a solid lifter than a hydraulic lifter. It's not that there is an interface issue between the lifter and cam shaft parts, but that the internal lifter component(s) are bottoming out, and the sound is emanating from this.

Once the lifter is allowed to lengthen, the internal lifter design is working properly. I think that a new hydraulic lifter is probably longer than the original 37 year old OEM lifter, much like a spring - gets shorter - like us as well, we all shrink with age eh what.

Happy camper for this evening.

Pontificating again. When the heads were refurbished, the engine compression was around 100 PSI and heading south. The compression is now in the 160 PSI range, a significant difference. Putting all this together into a cohesive mindset, cleanup and machining of the head and valves (? - valves are supposed to be replaced not ground), increased compression, new hydraulic lifters, brings everything into a new focus. This may not be entirely accurate, but it's the best I can think of right now.

Keep at it red

It's times like these that I really miss my father. Think of him always, but his old school counsel regarding all things mechanical, he was an old school type mechanic, was priceless.

Browsed the forums, internet and there is not a lot of information regarding adjusting a hydraulic lifter shim stack that was what I was looking for.

We are higher on the food chain then our bikes, hopefully, and it will be assimilated. Resistance is futile.

Bike back together and have done a road test.

The annoying ticking sound is gone, but will monitor. The intermittent FUEL SYSTEM dash light I saw is not there. Hard to diagnose an issue when it comes and goes.

Balanced the cylinder banks this morning, idle at 9 inch of Hg both sides. Bought a small can of quick start and sprayed all the connections I could think of, no air leaks.

Bit of a stumble at the lower RPM. Had this same issue, bit worse actually with the '85 Limited Edition I brought back from Ontario in 2018 I think. Checked everything I could and installed a new TPS; however, Tony from down under kept going back to the TPS as the culprit and he was correct. These items, extremely critical to the operation of the FI system, have some of the worse QA/QC in the business. Even a new one can be faulty from the get go. The signal from the TPS to the ECU is more of a chatter, than a fluid signal, and this has the ECU doing overtime. The TPS is also affected by excessive heat.

A faulty TPS that does not have the ECU generate an error code can change the timing such that the engine will fire in the wrong sequence and it will feel like the engine wants to do a hard stop. Very unnerving.

A faulty TPS may or may not create an error code. Can go in/out of calibration faster than the ECU can keep up. May show up on the dash light, then go away.

Have a few aftermarket ones on hand. Will be getting these ready to use, and try a few. Still going to remove the air chamber, flush the lines from the reed valves to the throttle bodies, and check the Tw sensor.

Cheers.

Found a web site that illustrates how to check a TPS with an oscilloscope. Shows good and faulty TPS signals. throttle-position-sensor-tps-22-1.html

Oscilloscopes are not my forte as one would say. Don't know anyone with one, if I did I'd have all my spare and installed TPS(s) tested for signal. Have tried using one over the years, big and handheld, but no success.

Bit of a no day today, but happy with what I have done. Morning coffee at the local Royal Enfield dealer. Had some rhubarb/apple crisp with coffee, and yes I was a piglet - had two small helpings. We did discuss the shim attack issue and Ken the owner was in agreement with my theory. He has encountered this in the past.

Decided to look for the mini handheld oscilloscope(s) that I bought back in 2019. I first purchased the DSO138 unit:


I think I screwed it up s I bought a fully assembled unit (don't remember purchasing it, been a while) a DSO138/150 type:

Thinking that I just insert this one into the circuit as if it was a multimeter and I should get some results. Went through the setup procedure, not too onerous and set up the TPS circuit. Had wires all over the place. Tested 4 TPS sensors and two are definitely not going to be used.

Will be installing the TPS unit that I was using before the engine rebuild. Worked well. Checked the wave form and it's not too bad. The small screen and resolution of the mini oscilloscope is pretty good but not big boy quality. There does not appear to be a lot of chatter on the wave form. This is the wave form from the modified TPS going from "0" VDC to approximately 5 VDC (using three AA batteries for the power source):



The is the wave form going from approximately 5 VDC back to "0" VDC:

Have a second one tested for signal chatter, but have to modify to fit because of the external alt mod, not a lot of room in beside the alternator.

Would have liked a larger picture, will look on line for a tutorial, and possibly find instruction(s) on how to resize the screen image.

Was looking at a larger, desk top oscilloscope, a FNIRSI 1014D. Nice unit - light/compact, bit more money, but resolution should be better. Thinking about it.

For testing the TPS, I would prefer an analog scope, and just watch for the signal smoothly increasing and decreasing. Probably most important in the lower voltage. For that, I'd just pass fairly low current through the TPS and sense the output vs ground use auto-trigger and a fairly slow sweep with range so that 0-5V gives at least half-scale. I've not had a 'scope for years and have considered one of the low-price units, but being more comfortable with analog scopes would probably go for an old used one.

The old analog scopes seem to be well respected and are commanding a good price. Had an older one a few years back when I first stated to look at the TPS. Too many dials/knobs, thought you'd have to be a wizard to learn how to use it. No manual either. Big and heavy as well. One of the low cost, if you can call north of $200.00 CDN low cost, digital ones may very well be on my to do down the road shopping list. Has to be in line with a new espresso machine I want to buy.

Spent the day changing out the TPS. Came up with a better modification that allows me to fit the aftermarket TPS in the space much better than last time:

Had to cut away some of the TPS plastic, but did that before. The main modification was the JB Weld of a new arm to connect the TPS to the throttle body linkage:

You will notice the original TPS arm on the rotor, but it is too far back from the throttle body linkage. Used JB Weld to attach a new arm that extends far enough to make good contact with the throttle body connection. I also moved the orientation so that I could turn the TPS for a better fit. JB Weld will harden quite nicely and nothing will move. You can see the TPS contacts because I had to cut away some of the plastic. Doesn't compromise the TPS.

Still have an erratic idle. Investigating this. Next time I strip off the plastics it will be to do the Tw sensor and flush the air chamber IAC air passages. Have time to think about the issue.

Looking into hydraulic valve adjustment and the impact of improperly adjusted valves on engine idle and performance.

Refurbishing the heads on the 1200 has apparently impacted on how the engine is operating. There is a slight erratic/rough engine idle and has been there for a long time.

When I peruse the internet I find lots of articles on what could be a problem/issue and most of these have to do with the fuel injection system components. Not a lot of articles/information on mechanical aspects that can produce an erratic/rough engine idle.

If you query hydraulic lifters and engine rough idle, or something similar, there are a few web sites that discuss this issue.

The reason I looked into this relationship is because of the issue I had with a slight, intermittent ticking in the engine that was resolved by adjusting the hydraulic valve shim stack.

I had the heads refurbished in 2018 (?) and I would expect that the shop ground the valve seats and possibly the valves to get a good seal. I do have good cylinder compression, but there is a possibility that the amount of material removed could impact on the opening/closing of the valves causing an erratic/rough idle.

It does require a lot of material to be removed as I found out with the ticking noise. Inserting a 0.69 mm shim in the #2 cylinder intake/exhaust valve shim stack got rid of the annoying ticking sound.

I want to investigate the relationship between the refurbishing of the heads and the install of new hydraulic lifters.

My game plan would be to do one cylinder bank at a time, use the 0.69 mm spacer/shims. The telling would be the change in RPM on the dash, and the sound - have to do this old school.

Do one cylinder of the respective cylinder bank at a time. If the engine idle does not smooth out, leave the added shims in the one cylinder and move on to the next. Since the erratic/rough idle is not too bad, may hit on a cylinder that needed that nudge to smooth it out.

Will be able to do this in the garage because an erratic/rough idle, no matter how slight, is generally more pronounced when at idle, everything seems to smooth out at speed.

My retirement project bike is definitely keeping me busy.

I hope they didn't grind the valves - that would ruin them. Stelited valves have a very thin layer on the sealing face.

I had a P300 random misfire code on a late 90's 4 cylinder car last month, one bottle of Marvel oil and one of O'Reilly's fuel injector cleaner made it go away in 1/2 a tank. Perhaps the stumble is a clogged or slow fuel injector? Disclaimer: I've never even seen a FI GL1200 though much less the injectors so there's that.

pidjones said:

I hope they didn't grind the valves - that would ruin them. Stelited valves have a very thin layer on the sealing face.

Click to expand...

Hear you. The shop is a reputable one so I'm hoping all that was done was a lick and a promise on the valves. Will carry on with the investigation. Expect to learn something in the process.

Motörhead said:

I had a P300 random misfire code on a late 90's 4 cylinder car last month, one bottle of Marvel oil and one of O'Reilly's fuel injector cleaner made it go away in 1/2 a tank. Perhaps the stumble is a clogged or slow fuel injector? Disclaimer: I've never even seen a FI GL1200 though much less the injectors so there's that.

Click to expand...

Injectors have been cleaned and flow tested, all was/is well. The injectors are very robust. I can't say that the injectors I swapped out were/are the culprit of the intermittent error code, just know that the ones I put back in have been working fine.

More exploratory work done. Decided to have at the fast idle on start, and then get on with the valve adjustment(s).

Took out the air chamber, Tw (water) and T1 (intake air) sensors. Checked the air passages from the reed valves into the intake - all clear. The Tw and T1 sensors are in spec.

Fast idle on cold start is alluding me. Starts, RPM drops then goes up and as engine warms up RPMs drop to idle. Now that I have checked the Tw and T1 sensors, will not dwell on the issue, but will keep looking.

There is a sealing/crush washer on the Tw sensor so no teflon type tape is being used.

Tomorrow will be putting the engine back together and getting at the valve(s).

Today was a whirlwind work day. Air chamber back in, everything buttoned up. Went at the valves.

Changed out the 0.69 mm shims I used on #2 intake/exhaust valves. Both are shimmed at 2 mm (2X1 mm).

#1 intake valve shim stack now at 2mm (2X1 mm). Had adjusted this shim stack from 2 to 1.
#1 exhaust - added a 0.69 mm shim and the idle worsened - removed 0.69 shim, stayed at a 1 mm shim as per initial check.

#3 intake already at 2 mm (2X1 mm) - no change.
#3 exhaust at 1 mm - added 0.69 shim, idle worsened, removed 0.69 shim.

#4 intake added 0.69 mm shim - idle worsened, removed 0.69 mm shim and stayed at 1 mm shim as per original findings.
#4 exhaust added 0.69 mm shim - idle worsened, removed 0.69 mm shim and stayed at 1 mm shim as per original findings.

Checked cylinder bank balance - vacuum gauges, good as it gets.

Checked cylinder compression:

#1 - 160 PSI
#2 - 165 PSI
#3 - 165 PSI
#4 - 155 PSI

I can live with these.

Started the engine up this evening after letting it sit for a few hours. Started well, idle did not drop, but increased to a fast idle for the temp. Not jumping for joy yet, time will tell.

The new battery, a LifePo4 lithium-ion, spins the engine over faster than the older AGM, better than the AGM new.

Cheers