82 1100E gets erratic when hot

[AJ88V]

Hi folks - My 1982 GS1100EZ seems to go wonky after about 45 minutes of riding. She's fine up till then, but suddenly starts to seem like she's misfiring. Idle gets raggedy and the sort of sputters like one cylinder isn't all there. Start her cold and she's fine again. I have my theories, but would appreciate hearing your ideas before I go down that path. - Thanks! AJ

(BTW, was active on this forum a long time ago, but seem to have lost my username...)

 

[Rob S.]

My '82 11E rode extremely hot until I installed an 1150 oil cooler. Now it runs cold.

What are your oil temps during these episodes?

 

[zuluwiz]

Check for air leaks in the intake boots. Had a GS1000 that did something like that, it had cracks in the carb-to-head rubbers that only showed up after about 30 minutes of riding. Gradually lost power till it stopped, when it was cooled off again it was good to go.

 

[dorkburger]

I'd agree on checking for airleaks. Also, weak coils have been known to become erratic when they get hot.

 

[Nessism]

Have you vacuum synced the carbs?

Is the bike stock? If you are running pods the jetting may be off. Running rich can often lead to the problems you describe.

 

[TxGSrider]

Might check your coils. Electrical stuff can get wonky as it heats up, especially the coils.

 

[Redman]

AJ,

You say the situation presents itself when engine is hot, and I gather not just warm, but hot.
If you said idle rizes high, then I would suggest intake leak.
If you said idle erratic (high then low rpm), then I would suggest carb balance-sync.
But you said seems like is missing, I would then suggest to add the spark plug caps to your list of suspects. THe caps themselves. They do go bad over time and usage and heat (the resistor in them goes bad). The caps can be removed and new ones are about 4 -5 bucks each. Dont need to be OEM, about any shop sells NGK. (I have part numbers for the 1100G ones, not sure if same for 1100E.)

Yah, if dont log on for something like 4 or 6 months, your username can expire. (Is what the administrator has decided. And he maintains the site as his own doing, so, we dont complain. Other option is having the site run by a for-profit corporation, with fees and advertisements.)

 

[AJ88V]

Thanks all! I'm glad I didn't give my own suspicions, as I never even considered the carb boots or the spark plug caps.

What I did suspect was the ignition system, thinking the problem shows up when things get heat soaked.

Already replaced the coils with some amazon cheapies that had decent feedback (but they're crap compared to the originals). No change - same effect - starts missing after about 45 minutes, which would seem to be enough time for the heat to soak up into the coils.

I would think the spark plug caps (or the carb boots, for that matter) would start showing problems sooner, maybe only 5 to 10 minutes after starting. But then both parts are largely polymer materials and don't conduct heat especially well, even if the carb boots are screwed directly to the cylinder head.

What I was about to do was replace the ignition system with a Dynatek unit ($$$), but then thought to post up here first.

Will try to pull the carbs this week and get a good look. She's been sitting since last year (gotta a bunch of bikes) so pilot jets are pretty much guaranteed to need cleaning.

 

[AJ88V]

Crap, I think I'm posting in the wrong section (big no-no, IIRC from years past). My apologies if anybody is offended (but don't let that stop you if you can point me to a solution!)

FWIW, this big old Suzuki is a hoot to ride (when she's running well). Power is enjoyable. Handling is totally anachronistic, but still fun. Brakes are kind of meh.

Best thing about the bike is that it is the favorite of passengers compared to all my other bikes. Why we ever stopped making bikes like this I'll never know.