83 650 gs trouble

[sixty8cat]

I got this bike in a trade. I have cleaned the carbs numerous times. It will start and idle fine. when I go to ride it...it falls flat on its face at 3K rpm. It will not rev past 3k. Where do I start. Was this a common problem or did someone mess with this before I got it. Owner said it just started acting up one day...thanks for any info.

[dr_fosg8]

Welcome to the forums! Basscliff will be along shortly with tons of good info for you. When you say you have cleaned the carbs, did you completely disassemble them, soak them overnight in a can of carb/parts cleaner? This can be obtained from just about any auto parts store, Napa or advance whatever is close. Replace all the orings inside? These can be had pretty reasonably from a member of the forums at cycleorings.com. This link will get you started on the carb clean if you need it. http://www.thegsresources.com/gs_carbrebuild.htm There are plenty of folks around here willing to help, you will get it figured out. Also, have you checked the valve clearances? I have to mention we like pictures around here. Of the bike not you, LOL

[Charlie G]

I have an 82 650g. It did the same thing your discribing untill I cleaned the carbs, replaced the internal o-rings in the carbs and the o-rings between the boots and the head. Do you have a stock air box? Are the jets in the carb stock? The previous owner used a rebuild kit to rebuild mine and it had the wrong jets in it for the stock set up. The stock air box needs to have good flexable boots connecting to the carbs with clamps and the filter acess opening needs to be sealed up tight so there are no air leaks.

Yea we like pictures

cg

[sixty8cat]

Hummm...thanks guys. I now have a Clymer manual and have a better idea as to what to look for. I will double check the jetting and the o-rings. Clymer manual is pretty vague. Is it possible that it will not run on 87 octane with ethanol fuel? Shoud I run something better? It acts lean. I know this from restoring old arctic cats with mikuni carbs.

[Charlie G]

Hummm...thanks guys. I now have a Clymer manual and have a better idea as to what to look for. I will double check the jetting and the o-rings. Clymer manual is pretty vague. Is it possible that it will not run on 87 octane with ethanol fuel? Shoud I run something better? It acts lean. I know this from restoring old arctic cats with mikuni carbs.

From what I've read they were designed to run on 87. Lean is my thought as well. There is a carb rebuild series as well as other links in Basscliff's site. If you haven't been welcomed by Cliff, go to owners section and introduct yourself, he will come along. Good luck.

I would be good to add the type of bike you have in your signiture so we know what bike you have. 650g, e, l or m?

Charlie G

[jbs80106]

FWIW, I regularly run 85 octane w/no problems at 8000ft alt.

What happens if it's on center stand and rear wheel off the ground? Can you rev it in neutral above 3k? Can you do it in gear but with rear wheel off ground?

Helps establish if it's a fuel delivery issue or something to do with it being under load?

Have you changed the oil and put the right amount back in? Once when mine overfilled (first time, what can I say! ) the motor just bogged down and limped back home.

[Larry D]

Do you have the airbox and filter installed ?

[tom203]

I got this bike in a trade. I have cleaned the carbs numerous times. It will start and idle fine. when I go to ride it...it falls flat on its face at 3K rpm. It will not rev past 3k. Where do I start. Was this a common problem or did someone mess with this before I got it. Owner said it just started acting up one day...thanks for any info.

Like others have said, it's most likely carb and/or airbox problem. But I'd also check to make sure my mechanical timing advancer is not stuck and thereby not advancing the timing.