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Discussion Starter · #1 ·
Hi.

Though this deserved a post for itself.

I just found vacuum leaks on 2 of 4 throttle shafts on my GPX 600 C1.

I imagine this would be a difficult area to vacuumseal from the factory and maybe it's okay to have some air passing.

Is this a repairable issue or should I just compensate for the leak with more fuel?

When I spray some break clean on the shaft the idle goes from 1100 to 3000 pretty quick. On both at the same time it goes even higher like 5000 or so.
 

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be careful, that sounds like the cheaper flammable brakleen rather than the non-flammable original stuff. I dang near burned my wife's car down with that stuff. apparently it had a marginal spark plug wire. That's when I learned the newer cheaper stuff was flammable,,,

Are you sure it's the shafts and not an intake boot leak or bad caps on the vacuum ports etc? new shafts could be difficult to even find if they're worn. Not familiar with those carbs, so can't say if they have o-ring seals or replaceable bushings on the throttle shafts, might check with KLsupply.com
 

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Discussion Starter · #4 ·
I know. It's very flammable so I was very careful doing it. I think It's isopropyl. It smells like it. I'm sure it's the shafts. I sprayed a very little amount with one of that red extension tubes and did only hit that area. I tried spaying the boots too with no effect.

The seals are felt seals and not easy to replace since the the butterflies has to come off.

A vacuum leak in that area will most likely only have an impact at idle since the vacuum becomes less important when the butterflies are open. I tried compensating by opening the fuel mixture screw 1/2 turn or so and i did a very big difference. Cleared the idle right up.

I cant figure out if it's okay to compensate that way or if it comes with disadvantages. I did a carb sync after. I'm guessing that the carbs with the bad shaft seals are sucking some of the air needed from the falty shafts and less from the butterflies compared to the carbs with good seals and that should be fine as long as the ratio is right. Right?
 
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