1980 GS1100E: Can't keep her running

[Guest]

I was wondering if anyone had an opinion on which direction I should go. It's okay to be candid; I know I'm weak in the mechanic department, but I want to learn more.

History: I bought her around 1990 and she was a basket case. I completely broke her down and rebuilt her (low compression in I believe cylinder 4?). I wish I could remember what I knew/learned in the process. My buddy had an '82 GSX1100E and was well versed with the bikes. I did all the work up to the valve job. I had a shop finish the top end. Bored to 1133; jetted; and dynoed.

Once it was back on the road it ran pretty good for awhile. Except that I would have to rev a little at idle at lights to prevent killing the engine. I stopped riding as much and she became progressively harder to start and idle (probably my ignorance to carb adjusting). I stopped riding and she sat for several years.

When I decided to get her running again she wouldn't. I figured bad fuel and cleaned, sealed and painted the tank. After a lot of work with several buddies (good bike mechanics) she fired back up after pulling a vacuum on her. She came alive and sounded great. After taking turns riding it was decided that she has a strong engine but needed a clutch kit.

Now I'm riding again and after a month I have fuel delivery problems (I guess fuel, she doesn't want to stay running). I decide to pay a mechanic (old school racer familiar with GS) to rebuild carbs. After all, it hadn't been done in 20 years. She ran great, minus the loose bolts and idle screw falling off. Then after a week I couldn't get her to fire up.

The mechanic talked me in to ditching the original fuel cock and putting in an after market Pingel. Nope, still no starto...

I haven't been able to get to her so she's sitting again. Last week I worked on her. I can get her started and keep her running by holding the choke fully open but not if I let the choke go or try to rev her.

My guesses:
1.carbs need to be rebuilt to make sure I didn't pay for something I didn't get.
2.jetting issue
3.balancing issue
4.valve adjustment needed

Oh, and running really lean, had to stop trying because I felt I would've got her too hot. Pipes discolored more further down...

Before I delve in and rebuild carbs and possibly adjust heads, would anyone be gracious enough to share their opinions?

[bluehwy]

typo

*adjust valves/not heads

[Agemax]

if you have fitted a pingel fuel tap have you blanked off the vacuum pipe from the carbs (that used to go to the pet cock) ?
if not you will get no fuel to the carbs and massive air drawn through the vacuum pipe. this will cause your symptoms

[rustybronco]

Before anyone can try to help you they'll need to know what mods have been done to the bike, if any, and if there are was bike was the bike re-jetted for them.

Have you checked the intake boots or air box boots for cracking, tears, pliability or not being clamped properly? Are there any exhaust leaks, missing or damaged exhaust baffles?

[bluehwy]

Agemax,
I have a screw in the tube.

[Agemax]

Agemax,
I have a screw in the tube.

fair enough, but as rustybronco says, have you checked all the boots for security and leaks.and is the screw in the pipe sealed properly?

if you remove the carb float bowl drain screws are they full of gas?

[bluehwy]

Rustybronco,
"Bored to 1133; jetted; and dynoed." (By an authorized Suzuki shop). I have not found any air leaks. All boots are pliable and new condition.

I mean it was running and then it wasn't. When fired up holding choke it is very lean. It's my suspicion that the guy who rebuilt my carbs didn't balance them well. I get fuel threw choke but not enough without choke.

After he worked on the carbs I had to play with the idle adjustment down the road well after letting her warm up. She needed help with the idle to get running and then would be warm and idling way to high. Talk about a pain trying to adjust the idle screw while at a stop light.

But I'm also curious if my valves aren't adjusted properly.

[bluehwy]

It's been awhile but I think I just jammed the screw into the tube. Should I use silicone? And, yes fuel flows when drain screws are loosened.

[Agemax]

sounds like you need to investigate your carbs further. the float heights could be set too low

[Big T]

If your friend rebid the carbs and the bike won't run, I'd immediately suspect all the other work he did on the bike.

Your carbs aren't flowing gas. Either they're still clogged, improperly assembled, or improperly adjusted. The fact that they will only run on the choke confirms this.

You'd be better off following the carb rebuild tutorial, so you know what has been done

Not wanting to idle is a classic sign of tight valves

The increasing idle is from a lean mixture, probably air leaks

[Nessism]

Sounds like the bike needs maintenance. It's very hard to diagnose running problems if the maintenance is not up to date. Clean carbs, fresh carb O-rings, properly adjusted pilot screws, vacuum sync, check coil voltage, verify carb jetting is correct though plug chops, etc. Bikes more than 30 years old and needs some TLC.

You can find lots of good info on Basscliff's website to help you along...http://members.dslextreme.com/users/bikecliff/

[bluehwy]

I have downloaded his generous carb rebuild info. I guess I will start with that.

Should I wait to see if that solves the problem before trying to adjust the valves? I lapped them 20 years ago with a friend's help and maybe don't trust I completely knew what I was doing after what I've read on this forum. Unfortunately it was so long ago and the day after a vasectomy that I did that valve job (not smart?). I'm sure I did new sleeves and seals but not sure if I measured anything.

Oh and correction, I trust all of the help from my buddies. I've seen, worked with, and rode some of there classic/vintage rebuilds. The shop that rebuilt my carbs, however, is not one of those friends. And I'm skeptical about other stories of what's come out of his shop...

[bluehwy]

I'll have to be sure to verify carb jetting. Very unfamiliar territory for me. I think I got the concept, fuel flow?

[Big T]

Fuel flow indeed

As a big bore 1100 should pull very hard when you open the throttle, It sounds as though you bike has never run correctly

You should verify the cam timing while you're checking the valves

[bluehwy]

Thanks Big T. This may be why an expert couldn't adjust the carbs. Maybe I'm fighting something more than just fuel from carb?