82 650 Idle oddness

[bradbenz]

I have an 82 GS650 that has been acting up a bit.

Bike starts and runs fine during my 7-mile ride to work. However, it does seem a bit sluggish off the line, but no real stumble or hesitation. Just revs up slower but steady.

On the ride home, the thing runs great; pull is much stronger. However, at most every stoplight, the idle climbs up to between 1500 and 2500rpm. If I kill it, and restart, it's back to normal (<1000RPM)

I just had the carbs sync'ed, and like I said, its running smooth otherwise.

Thoughts?

-b

[Nessism]

Sounds like an intake boot O-ring leak.

[bradbenz]

I was wondering about something like that, since the changes in behavior react to temp.

Do you mean the boots between the carbs and the engine?

-b

[maro]

I'm thinking air leak. Check orings, carb boots, air filter, etc, etc. Sounds like you are running lean. Check your plugs. are they white? Check your pipes, are they all Hot?

My bike is lamo off the line too, I mean it's fast...but not fast enough I feel. Too many cars can outrun me off the line. Someone will chime in and say that is not how it should be, but on the road I take to work, Cagers think it's a god dayum race track, and want to FLOOR it everytime I get next to them. Unless I FLOG and POWERSHIFT quickly, they usually can get ahead ... Once I'm third though, I go right by them. Knock on wood, my bike is riding smooth, everything is firing, so... Just the nature of these bikes I think....bikes meaning 650's

[bradbenz]

I'll focus on the air leak possibilities, then...

Thanks a ton!

[doctorgonzo]

I'll focus on the air leak possibilities, then...

Thanks a ton!

That's Nessism's first answer to every question including where is Jimmy Hoffa buried, BUT, he's probably right more often than not. It's ridiculously common on these bikes, and gives those kind of symptoms.

[bradbenz]

Should I focus on the entire route of airflow, or just downstream from the carbs?

[doctorgonzo]

Should I focus on the entire route of airflow, or just downstream from the carbs?

All of it. Leaky airbox, leaky boots between airbox and carb, leaky boot between carb and head. You can spray carb cleaner on the boots with the bike running and if the idle rises, it's leaking.

[bradbenz]

Excellent! I'll give that a shot!

Thanks again!

[Nessism]

That's Nessism's first answer to every question including where is Jimmy Hoffa buried, BUT, he's probably right more often than not. It's ridiculously common on these bikes, and gives those kind of symptoms.

GS intake boot leakage is more predictable than gravity. If the O-rings are not leaking now, they will be soon.

[bradbenz]

So it was indeed an air leak. Or multiple air leaks. Yesterday I got around to pulling the carbs again, and re-assembled (using a bit of silicone grease on the boots). Greasing the boots a SMALL AMOUNT with something that is rubber friendly made all the difference when reassembling. The character of the bike has changed so much that I was a bit caught off guard! Pulls harder in every gear, idle is smooooove, and it feels like the bike I knew it could be. I can tell I have to balance the carbs a bit; I'll tackle that one tonight.

Again, thanks!!!

-b

[mcloud]

So it was indeed an air leak. Or multiple air leaks. Yesterday I got around to pulling the carbs again, and re-assembled (using a bit of silicone grease on the boots). Greasing the boots a SMALL AMOUNT with something that is rubber friendly made all the difference when reassembling. The character of the bike has changed so much that I was a bit caught off guard! Pulls harder in every gear, idle is smooooove, and it feels like the bike I knew it could be. I can tell I have to balance the carbs a bit; I'll tackle that one tonight.

Again, thanks!!!

-b

That'll be $22.68 taxes included sir.
Thanks for shopping at GSR...
Oh!?! you're right... It's free

[bradbenz]

LOL. I'm not sure how *free* it was; cost me 2 knuckles, 4 beers, and YET ANOTHER session wrestling with one of the most ill-executed ideas in motor engineering; the GS Airbox. Ugh.

Thanks again!