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Bike run poorly when warm. Gl1100

Posted: Mon Jun 03, 2019 12:00 am
by Dos.Honduros
Hello, I could not find a posting that matched my issues. Please forgive me if I missed it.

My 1980 gl1100 starts and runs fine. It contiues to run fine until It warms up after about 20 mins. Once it’s warm it starts to miss/backfire and begins to idle high. Also when you turn the throttle it gets real erratic but will not gain rpms. It’s like it’s stuck at the high idle. Also when I turn the throttle it makes an odd whirring noise in the air box. It’s almost like the timing goes out of whack when I turn the throttle.

If I shut it off it and let it sit 20 minutes it will start and run fine for a while before doing the same thing again.
The difference I am seeing between my issues and similar issues is that mine is not dying.
Any help would be appreciated, thank you.

Re: Bike run poorly when warm. Gl1100

Posted: Mon Jun 03, 2019 12:35 am
by Dos.Honduros
Here is a video of what is happening after it warms up.




Re: Bike run poorly when warm. Gl1100

Posted: Mon Jun 03, 2019 7:21 am
by virgilmobile
Cold runs and revs fine..Warmed up and it sputters when revved..
Seems to be firing on all 4.
I'd stick a mirror in the plenum box and have a look at the slides when it's acting up.
They may be sticking closed.

Re: Bike run poorly when warm. Gl1100

Posted: Mon Jun 03, 2019 7:52 am
by virgilmobile
Cold runs and revs fine..Warmed up and it sputters when revved..
Seems to be firing on all 4.
I'd stick a mirror in the plenum box and have a look at the slides when it's acting up.
They may be sticking closed.

Re: Bike run poorly when warm. Gl1100

Posted: Wed Jun 05, 2019 8:39 pm
by Dos.Honduros
ok update: thanks for the advice Virgil, looks like they are opening and closing fine.

heres a weird symptom I found:
I know it is an issue with electronics because the more accessories I turn on the better it runs. it will be idling poorly and will just sputter and not rev up under throttle. but if I turn on the radio it will run a little better but still poorly, then if I turn the CB radio on it will run a little better yet but not perfect.
so I'm guessing a voltage regulator? anybody else have any ideas? does anybody have any expertise in gl11000 voltage regulators?

Re: Bike run poorly when warm. Gl1100

Posted: Wed Jun 05, 2019 10:32 pm
by virgilmobile
Strange...Can you measure the battery volts when it's running bad?
Expect it to be between 12.3 and 14.2 volts.

Re: Bike run poorly when warm. Gl1100

Posted: Wed Jun 05, 2019 11:15 pm
by Dos.Honduros
Nevermind I figured it out. It was the master link.

Re: Bike run poorly when warm. Gl1100

Posted: Thu Jun 06, 2019 5:16 am
by virgilmobile
A electrical problem..Great job finding it.