Carburetors and Old Bikes

[Sidewinder]

When one of these old bikes follow me home, (and too many have been doing that lately) one of the first things I do after checking the visual stuff and compression check is take it out, get it good and warmed up and if everything else being somewhat normal, give it a good run slamming the throttle and general street hooligan antics for a few minutes and do a plug chop pulling back into the shop. This Gl1100I is about the 8th one of these old gals I've messed with in the last 7-8 months and just like all the others it just didn't perform like it ought to.

Everyone of them had various issues but one thing in common with all of them is the carbs are a major source of the bikes problems. This is expected and I am no longer surprised by anything I find. "Showroom condition" "always kept in garage" "runs great" "never a problem" are the usual descriptions owners give for their "babies" when in actuality they are holding on to a set of problems they don't want or can't figure out how to correct. This one is no different.

First thing I noticed was it was a pig and rode like it was on 3 1/2 cylinders along with a nice backfire when decelerating from high RPM if given enough time. There were of course other issues but that's not what this is about.

I filleted the carburetors and since this is the first 1100 I've been into I just split the plenum and decided to do the right bank first so I could play with then and see where and how everything worked. I use an ultrasonic bath to clean with but it's not big enough to do the whole set anyway so that's another reason.

I did numbers 1 and 3 first and both air cutoff valves were toast and the accelerator pump had to be pulled with pliers and considerable force. The low jets were a bitch to get out as they are pressed in and these had never been molested but were clogged up fairly well.

It's apparent that someone has soaked these at some point calling it a "cleaning" and with chemicals because one ACV was eaten almost completely up and the other was DOA.

Here's the one that was disintergrated

And this one shown on a flash light to see what's missing. These things are vulcanized rubber and the chemicals ate away the rubber so only the mesh frame is left in spots. Even a pin hole in one of these will affect the smooth operation of the Carburetor so, if you are new to bikes and doing your own work or even if you are an old hand and just hard headed ..... don't do it. Chemical cleaning is a thing of the past for me. I am so sold on the ultrasonic I'm looking around for a larger unit. Pricey yes, but worth it.

I clean for a while and get bored then I get to looking at all the neat aluminum so I go over to the buffing wheel for a while. lol Pretty much finished with the right side so I stuck 'em back in place for the obligatory before and after photo.

While the heart transplant is going on I may as well put new timing belts on so that means I get to polish the butt ugly covers this weekend. The weather is suppose to be crap here this weekend so I look forward to buttoning it all up and see what a real Goldwing performs like next week.

 

[slabghost]

While you are into the cam belts you might want to loosen all the lifters until you get the belts exactly right. Then adjust all the valves to the max allowable clearance. They close up over time. This will also give you the opportunity to polish up those oh so visible valve covers.

 

[joedrum]

man those cleaners can be distuctive on carbs ...

 

[backlander]

I wonder if "stable" does that. I run it in mine, every tank and so far no carb problems.

 

[joedrum]

i was talking cleaners for carb rebuilds ,,,,but if i were you id run atf as a fuel additive its better than stabil and cheaper and it super good for carbs

 

[backlander]

i'll try the atf then, thanks joe.

 

[dan filipi]

I'm pretty sure some gas additives cause this.
When I first pulled my carbs those cutoffs looked just like those in the picture.
I had run a few different cleaners, I'm thinkin b12 chemtool was the culprit but I can't say for sure because I didn't see the condition of them before adding it. Either way, I stay away from ALL additives other than ATF in the gas.

 

[backlander]

after I saw that pic, I got worried cause there's bound to be some chemicals in those additives for them to do their job and even if they didn't do immediate damage, they might in the long run. I'm switching to the atf.

 

[dan filipi]

Supposedly Seafoam is safe. There are hundreds maybe thousands of riders that use it regularly with no complaints but for what it takes to replace the cutoffs and how much they cost, (Seafoam isn't cheap either) riding the bike often and running ATF is a safer solution. After all it's the sitting with gas in the bowls that causes the most problems.

 

[Sidewinder]

While you are into the cam belts you might want to loosen all the lifters until you get the belts exactly right. Then adjust all the valves to the max allowable clearance. They close up over time. This will also give you the opportunity to polish up those oh so visible valve covers.

Thanks for the tip slabghost, I just adjusted the valves a week ago and two of the valves we indeed closed more than they should be.

 

[Sidewinder]

I guess the ATF is just a type of top oil like Marvel Mystery Oil is. Many years ago racing fuel was hard to get and I had to drive a long way to get it so I started running 115/145 av gas in my race car. But it is so dry there was a risk of burning a hole in pistons so I had a formula for adding MMO to the av gas to fix that problem. I would think that MMO nor ATF would damage any of the rubber but can't say that with authority because I never tested it and the engines I used it in had no rubber diaphragms.

I know the carb cleaners will eat up rubber and now wonder if ethanol may contribute to this because 4 out of the last 5 bikes looked exactly like this when I went into them. Got a 450 Rebel that was far worse than these were, the cutoff valves were unidentifiable in that bike just a big glob of goop.

Surprising thing about this bike is it really didn't run all that bad in this condition. It was sick and idled goofy but some people might have just rode it that way. However it was just a matter of time before it laid down on someone and likely at night far away from home. :whistling:

Has anyone here removed the idle jet from '81 carbs, the pressed in type? I used a #1 extractor but it didn't want to get a good bite and ended up taking it out with a #2 (slightly larger).

The side holes in that jet's emulsion part measure .026 (#71 bit) but the main oriface is much smaller. It won't take the smallest I have (.018) so I'm going to take it to the place where I get my bits and size it. I can't find ANY specs or drawing on Keihin jets anywhere on the net. One guy I know who is expert in carbs says he THINKS it's a .0145 but wasn't positive. Even though you can clear these holes unless you run the proper size bit through it there's still a minute layer of corrosion from years of water etc exposure which act to close the opening ever so slightly. Running a proper bit through ensures bringing it back to factory spec's. (maybe I'm just anal)

 

[slabghost]

While you are into the cam belts you might want to loosen all the lifters until you get the belts exactly right. Then adjust all the valves to the max allowable clearance. They close up over time. This will also give you the opportunity to polish up those oh so visible valve covers.

Thanks for the tip slabghost, I just adjusted the valves a week ago and two of the valves we indeed closed more than they should be.

If you back off all the adjusters while you install the belts you eliminate possible damage from a valve hitting a piston if the belt somehow ends up a few teeth off. Resetting them after you are certain everything lines up is just good practice. As for the carbs. These days almost every old bike regardless of make or model if it has sat any time has pretty much the same issues. Those with less rubber in them have less issues but they all have some. I'm in the camp that it is the fuel itself in most cases. Back when these were built there were no fuels with alcohol extenders. Now it's nearly impossible for most of us to find any fuel without. Combine that with all the other additives something has become destructive to old rubber parts.

 

[Sidewinder]

These days almost every old bike regardless of make or model if it has sat any time has pretty much the same issues. Those with less rubber in them have less issues but they all have some. I'm in the camp that it is the fuel itself in most cases. Back when these were built there were no fuels with alcohol extenders. Now it's nearly impossible for most of us to find any fuel without. Combine that with all the other additives something has become destructive to old rubber parts.

I agree with that. That's why I will just get Randall's kit and install it on all these when I first get them. His kits use viton material which is not harmed by such stuff. (Best of my knowledge that is true of the material) All the cut off valves in this bike are at a similar state of deterioration. The accelerator pump was okay but the metal part had rust and corrosion indicating the amount of water those fuels attract. That's another problem with the fuel containing any alcohol, the water attracted. Since the government mandates that crap fuel there's almost no escape from getting it in your tank. Although using the Viton material on formerly rubber parts defeats the effect of the fuel, the aluminum passages and brass jets still fall victim to the buildup of years of corrosion caused by the attraction of water in the system. That's the reason I bring the hole sizes back to original. I first did this on my CX650 and there was a noticeable difference in the power, feel and efficiency of the engine after taking the pain to completely clean out every passage and orifice making sure all evidence of the buildup was removed. It's there, especially if the bike has sat for any length of time. Even after normal cleaning, looking with high magnification you could still see it. That's why I went to the heated ultrasonic cleaner. It gets most of it off but takes hours of running in the tank with many flushes and lots of compressed air.

Just another example of government's "unintended consequences". OR NOT> fuels today suck but then again the quality of many other things is degraded also so, as long as people accept the lower standards we will just race to the bottom. Guess I'm getting political so I'll leave it at that but this is the stuff the fry's my A$$. :rant: :rant: :rant:

 

[Omega Man]

Sidewinder, those carbs are beautiful. I didn't realize one could completely revitalize the look of the carbs and other parts like that with a polishing wheel.

~O~

 

[Sidewinder]

I wonder if "stable" does that. I run it in mine, every tank and so far no carb problems.

I would almost doubt that Sta-Bil does that. However, I would run the new Marine formula Sta-Bil which is specially formulated for ethanol fuels. There is a difference, with the marine version containing 4 times the fuel system cleaner than the regular Sta-bil and better ability to deal with the water attracted to the alcohol in today's fuel. I think it would help prevent the corrosion caused by the water.

Interesting stuff from a paper I read about the effects of the ethanol laced fuel. The shelf life of E-10 gasoline is about 6 weeks to 90 days before it will decompose. E-10 of course, is 10% alcohol. So if you store your ride for three months and the humidity is high you got water. That's because the alcohol is hydroscopic, meaning that it pulls water out of the atmosphere and merges with the alcohol. Since gasoline floats on water the water laden alcohol settles to the lowest point and gets into places where the corrosion will build. At first I couldn't figure why the corrosion in all these carbs but after reading this I understand.

Years ago when I was fooling with race cars I tested lots of fuels, same engine, same dyno. NO two pump fuels are alike. Same rating different pumps = different results. Put all sorts of fuels in the mix and racing fuel didn't produce the best HP. Ended up using a common pump fuel that produced the best results for the Spec engine we were running. Of course we didn't tell anyone nor even now interested in telling what brand but you WILL get a different fuel at every pump. The difference might be slight or huge but nonetheless different. Fuel reaches the final pump and the consumer has no idea of its history. It could have been stored for months or rushed straight from the refinery. In the case of today's world using ethanol that could make a big difference in what you end up with. That's because with the addition of the alcohol it only stands to reason that the stuff attracts water and the longer it sits before final sale and use the more contaminated with water it becomes. No spark plug I ever saw will ignite water so there ya go.

I know I'm picking at "nits" here but these are physical facts and from what I have seen of old carburetors then and now there is a difference in what they look like compared to say, years ago before the introduction of ethanol.

Talk about :deadhorse:

 

[Sidewinder]

Sidewinder, those carbs are beautiful. I didn't realize one could completely revitalize the look of the carbs and other parts like that with a polishing wheel.

~O~

Well, it's a little more than the wheel but you get the idea. We will have to get together sometimes and talk motorcycles since you're in town. Don't mind helping a fellow rider with what little I know.

Anyone can do this with the right stuff and not minding getting dirty.

 

[Sidewinder]

Okay, here's a chart I came across about fuel additives. Don't know anything about he site owners or their motivation (cui bono) just the name Fuel-Testers.

https://www.fuel-testers.com/is_gas_additive_safe_with_e10_list.html

I know lots of bike owners swear by Sea Foam and a ton of it is sold every year. Personally I don't use it and the only thing I have ever put in a fuel tank of this nature is MMO on certain occasions looking for a particular result. (saw my dad and uncle put nitroglycerin mix into some fuel once that blew the engine to smithereens but, that don't count) Notice on this chart it is NOT recommended for an additive to ethanol laced fuel. Reason given was that one of the ingredients in Sea Foam is listed as IPA. IPA might mean Isopropyl Alcohol. There was a note on the chart as follows: (2) Seafoam MSDS lists "IPA" under ingredients. The only commonly used term for abreviation IPA =Isopropyl Alcohol. Isopropyl alcohol is soluble in water. Seafoam Sales Company did not respond to our request for more information.

So, here's my thinking on this. The addition of Alcohol to fuel is the Direct Proximate Cause of heretofore unseen problems concerning carburetors and especially older carburetors; If, the introduction of alcohol into the fuels available is the cause of these problems (eating up the insides and poor running due to phase separation) Why would ANYONE want to further exasperate an already crummy situation with the addition of more alcohol in search of a solution to the poor running conditions caused by this substance in the first place. Sort of like curing a hangover with more booze. In addition, using such a thing as a preventative seems akin to some mid evil "doctor" attaching leeches to a body to cure the clap. Or, in my case, like my Grandmother forcing two tablespoons of castor oil and Milk of Magnesia down my throat because I "Looked sick".

I know I'm apt to catch a lot of flak for this opinion being new here and all but until I can prove to myself (or someone else can) that I'm wrong I won't be adding any of that stuff to my fuels.

The additive market is huge and there has to be some benefit to SOME of the stuff out there but from my experience the majority of success in that business is directly related to the level of advertisement. That includes word of mouth. Who wants to admit that they paid $9-$30 every few tanks of fuel and derived no real benefit and may actually made matters worse with the application of "black magic".

 

[Sidewinder]

almost all fuels have a percentage of ethanol in them it is made from corn like that liquid at the bottom of corn sillows that is distilled go figure alcohol so it is everywhere theses days

Never has, and never will make any sense to me to burn food as fuel. It takes 6 bushels of corn to make one gallon of good whiskey. That's a much better use for corn.

In fact, part of the reason for moonshiners existing is steeped in history and tradition along with just good common sense. When the country was just founded farmers who sometimes had excess and sometime lived lean due to weather and other things would store their corn and the best way was to turn it into whiskey. He might not be able to sell the corn in plentiful times but he could always fire up the still turn it into something the would get better with age as opposed to spoiling in it's usual state. One of the first indications that government might present problems among the people was when George Washington decided to tax whiskey. That led to the Whiskey rebellion and that's been a sore point ever since. Of course government won and taxes on about everything remotely connected with life have proliferated since. Considering the tax on fuels and the government mandate on the addition of "corn" to it and one can come to some conclusion about the hair-brained idea and it's genesis. It's just pop culture and will eventually blow away but in the meantime we won't outlive the madness, these things take time, lots of time.

Meanwhile one can't enjoy an old bike without first overcoming the result of "unintended consequences" Now how's that for a stretch of the imagination. This is all George Washington's fault for screwing with the farmers to begin with and he produced more whiskey that most in Virginia to begin with. I'm beginning to think all politicians share some gene or something. :head bang:

 

[joedrum]

no flax from me thats absoulutly right ...seafoam is a cutter and is lousey gass addative on a continuous use ....MMO and ATF are much the same but ATF is better still as a additive on continious use ....atf is made to keep seals good and soft in a recirculating bases ....it will never allow carbs to get coated and gumed up with anything period ...it even makes the crappy gas better and the bike will run better

 

[dan filipi]

No flak from anyone here, we're not like that.

When ya have the money to throw around trying out gas additives ya don't think about it too much,
but when money is tight ya start paying attention to whether the stuff is actually doing anything.
That's me.