Just picked up a bike, already having problems

[Token]

Hey all, I'm new here. I just picked up a 1981 GL 1100 the other day and it seemed to be in pretty good condition. Just yesterday I was riding it around and it felt great.

This morning I started it up and it feels rough. It won't idle anymore without dying, and if I try and hold the rpms at a certain place it seems to struggle to do that. Everything just feels and sounds worse than it did yesterday. On top of that I'm noticing a loud knocking at low rpms that goes away when I throttle it up a bit.

What could have happened?

[Maz]

Sounds like your carbs have picked up some crud. These engines knock like mad when idling on less than all 4 cylinders. Start it from cold and let it idle as good as it can for a minute. Tap each exhaust header with a damp finger - the hot ones are the cylinders that are firing. The cold ones aren't firing. Possible carb clean due, and make sure you change the timing belts if you don't know when/if they have been done.
Maz

[Token]

Thanks for responding! Crud in a carb is what I was thinking. I might have accidentally switched the fuel selector to reserve and sucked some crud out of the bottom of the tank.

I'll try and see if I can figure out which one isn't firing when I get a chance, thank you.

As for the timing belt, I assume it being a old honda motor its a interference motor? If so I'll make sure to do that soon

[AZgl1800]

ummmm,

I prefer using an IR Temp Gun to fingers on exhaust header.

[DenverWinger]

Yup - interference motor.

Honda OEM belts are available, and incredibly 'Spendy'.

Gates T274 Or NAPA Autoparts #250274 Fit exactly. You need TWO belts.

Guess what? The Honda OEM belts were made by Gates, and the NAPA Autoparts #250274 belt is a Gates belt.

The belts are available at your local autoparts store for about $40 each. About $75 ea. from Mother Honda. And about $18 each from Amazon. All of them are the same Gates belt.

[Maz]

ummmm,

I prefer using an IR Temp Gun to fingers on exhaust header.

Yeah, me too, but I didn't want to assume that he had one laying around. Most people have a finger or two available and dampening them is fairly easy! It's a quick and easy way to establish which cylinders are firing/not firing. Maybe I should add the warning "Be careful though... It may be hot! "
Maz

[Overdog]

Always a good idea to check the reserve setting. I can't remember which forum I was on but somebody said that the first time they had to hit reserve on their oldwing they were stranded, as the reserve pickup was blocked. If you sucked some crud from the bottom of the tank I would think that your fuel filter would stop it before it hit the carb....did you check/change the filter?

[Johnyy Smoke]

Fuel filter is a good suggestion. Any other probs? Know any history of the bike? We like pictures! Regards, Johnyy

[Token]

Just got out today and put a new starter on because the old one went bad on me. It seems that my carb cleaning helped for the most part. It will idle all day long I believe, it still sounds like it can't hold a rpm very steady though. I for sure have made progross, it's absolutely rideable as is and is a blast. I bet the carbs just need to be synced or something simple at this point.

Thanks guys for all the help! I still need to get some pics for you all.

[Maz]

Mmmmmm... Pics... We love pics!
Maz