1980 GS1000G Revs Between Shifting

[Guest]

Hello folks, late last year I did a total overhaul on the carbs, air-box and replaced all the intake boots and air-box boots. Synced the carbs and was running pretty good. Took her out for a spin tonight and between gears she dos not idle back down and stays at the rpm for the gear she is in. When I got home after a long ride she idled up to about 3 grand as I was opening the garage door. Would this be the throttle cable going bad or some other adjustment I missed? because of the bad winter in Jersey this is pretty much the first time I really had her out for a long ride.

Any help is appreciated.

[Dogma]

If it takes several seconds to come back down to a normal idle, that's usually indicative of an intake leak. Does it come back down?

[BillGS550LZ]

In my experience, iddle hangs due to air leaks causing a lean condition, a lean condition related to fuel mixture screws being turned to far in (mine is an 82 gs550 with a rack of four Mikuni carbs smaller but I believe similar to yours), and throttle cable too tight or binding.

Throttle cable check is easy, engine off, roll throttle and let is snap back, you should hear a definitive clank, if not cable may be binding or too tight. The throttle should have one or two mm free play. Also I have bar end mirrors which used to interfere with the throttle handle just enough to hold it slightly open.

Air leaks, spray carb cleaner around the intake boots, if engine speed raises, there is the leak.

The idle mixture screws should start out at 2.5 turns out then adjusted to highest iddle from there. In lean, out rich.

Oh also may want to check your chocke. Mine raises with chocke on after warm.

I am sure others more familiar with your ride will provide more accurate/relevant info. Good luck.

[njload]

It does idle back down when shifted to the next gear but between shifting was the issue. I was figuring I would have to remove the tank and warm it up and test things out again.

Thanks for the replys

[tom203]

It does idle back down when shifted to the next gear but between shifting was the issue.

When shifting (in between gears), engine load is reduced enough to let an air leak boost idle.

[Dogma]

Throttle cable check is easy, engine off, roll throttle and let is snap back, you should hear a definitive clank, if not cable may be binding or too tight. The throttle should have one or two mm free play. Also I have bar end mirrors which used to interfere with the throttle handle just enough to hold it slightly open.

Throttle cable slack is at the minimum with the bars all the way to the right. There should be a tiny amount of free play there before you feel the tension from the return spring. That's pretty much it. If there's no slack at the closed throttle position, then the cable is too tight.

My 850 has clogged up carbs that make the bike take forever to warm up. As in, not warm until after a few minutes at speed. If I set the idle to keep it running before that, it wants to idle around 3k after warming up. I'm finally getting around to dealing with that...

[loud et]

One other "stupid" thing to check is that the sync screws/brackets (between each carb)are not hitting your intake boot clamps. One time I moved my intake boot clamps and they were binding on that part of the carb that moves when you twist the throttle.
One of those dumb things to check.

[njload]

Ok finally got time to remove the seat and tank, warmed up and sprayed carb cleaner and it looks like an air leak around the intake boots. I tightened up the clamps as far as they would go and it still does it. What is the cure for this?

any help is more than appreciated.

[Dogma]

The carbs come out of that thing in 10-15 minutes. Don't be afraid to dig in and find out. Maybe a loose balance port screw? Won't know 'till you get in there. New boots shouldn't be cracked after just a year.

[tom203]

Recheck carbs and best to replace o-rings at head/boot interface if you haven't already

[njload]

everything was replaced and rebuilt. the new clamps are as tight as they will go. looks like number 3 and 4 carbs are the ones that are leaking a bit. the clamps seem to be in the correct spots, so my question is what next? if i put a regular hose clamp on will it tighten enough to stop the leak?

thanks for the replies, looking to get this thing going soon.

[njload]

does anyone know the torque specs for the intake boots off the top of your head? Just removed the air box and carbs and was able to turn the screws a bit.

any help is appreciated.

[tom203]

Just tighten them down - those nice new (?) o-rings will seal nicely.

[Agemax]

take them off, smear the o rings with silicone grease, refit and tighten them up.
make sure the o rings are sat in the grooves properly before fitting. the grease will help them stay put, as well as ensuring a good air tight seal.

[njload]

Ok Thanks for the replies, but how about the torque specs?