1000+ rpm raise after riding for a hour or so

[Guest]

carbs need synced i know this

but i have the idle at 900 +/-100

then after 20 mins or so it will be about 1500 +/-100 or so


then after a hour or so its around 2000 +/- 200


would the carbs being out of sync do this?

or any other ideas

[Nessism]

Have you replaced the intake boot O-rings?

[jbs80106]

sounds like an air leak at the carb boots...could be either side. mine did/does this but I haven't replaced the carb boot rubber yet. No matter how tight you get the hose clamps.

Annoying, yes.

Embarassing...at a stop, yes.

Damaging...depends. I think it means she is likely running LEAN (too hot!). If where you live it's very hot in the summer over time this can be very bad. For me, the least of my worries as I never rode more than 60 mins or so.

Bad news is I've been shopping for boots myself. Seem to be $25-30 EACH...x8 that a lot of green! But easy enough to fix.

Might as well visit cycleorings.com and order up those too...for $14.00....(much better!)...

and put 1 issue to bed...

[Nessism]

Carb boot O-rings are cheap. Most of the time that is all you need. Running the bike with a vacuum leak can damage the engine so it's not advised.

[gearhead13]

Bad news is I've been shopping for boots myself. Seem to be $25-30 EACH...x8 that a lot of green!

x8? You running a V8 in that thing?

[blowerbike]

4-head
4-air box

[SqDancerLynn1]

You might check the petcock vacuum line, Carb sync can change the idle, but more likely an air leak as things expand when hot

[Dave8338]

4-head
4-air box

I just hate math...

[Skateguy50]

sounds like an air leak at the carb boots...could be either side. mine did/does this but I haven't replaced the carb boot rubber yet. No matter how tight you get the hose clamps.

Annoying, yes.

Embarassing...at a stop, yes.

Damaging...depends. I think it means she is likely running LEAN (too hot!). If where you live it's very hot in the summer over time this can be very bad. For me, the least of my worries as I never rode more than 60 mins or so.

Bad news is I've been shopping for boots myself. Seem to be $25-30 EACH...x8 that a lot of green! But easy enough to fix.

Might as well visit cycleorings.com and order up those too...for $14.00....(much better!)...

and put 1 issue to bed...

You still shopping for boots? Lurch has some 650 parts up for sale in the parts section. I saw the parts bike and all looked pretty decent. I would say getting some used boots in good shape is a much better option than new ones for something that expensive. Some of the old rubber survived some didnt, really depends how it was used and stored.

[Im Faster]

okay.. so i have the orings.. but this may sound dumb but i dont understand how they fit in the boot.. there is a metal type oring but thats not what i got to replace

[Dmason]

Im having the same problem. It's the last problem before my bike is 100%. My mechanic thinks it's an air leak. It sits around 4000rpms at idle, mostly when Im at a stop sign. I wonder if it's any of the aforementioned problems such as: petcock vacuum leak, carb boots, or bad o rings.

[Nessism]

Im having the same problem. It's the last problem before my bike is 100%. My mechanic thinks it's an air leak. It sits around 4000rpms at idle, mostly when Im at a stop sign. I wonder if it's any of the aforementioned problems such as: petcock vacuum leak, carb boots, or bad o rings.

Leaking intake boot O-rings is the number 1 most common GS problem - it causes the idle to hang, and sometimes never come down. Apparently you guys don't do maintenance on your bikes, and don't read the archives either.

[Dmason]

Leaking intake boot O-rings is the number 1 most common GS problem - it causes the idle to hang, and sometimes never come down. Apparently you guys don't do maintenance on your bikes, and don't read the archives either.

Hey hey hey now, take it easy on a newbie. I bought this bike broken and am in the process of having it fixed. This is my first bike, and I wanted one so bad, that I made the mistake of buying a money pit from a guy that scammed me. It is now essentially almost 100% and I have made great strides to get this thing working.

But to hear it might be something as simple as a leaking intake boot O-ring is music to my ears. Thanks Nessim. Looks like its time to hit up cycleorings.com