Loss of power and random high idle

[SpanishBob]

So all of a sudden my bike has lost so much power. I really have to ride the clutch to take off and top speed is 65mph in top gear. And once in a while when I am at a redlight the bike idles high. When I rev it the RPM doesn't fall fast like it should. It will either hover between 3-4k or drop down slow to around 1.4k where I have it set. This bike is starting to drive me crazy!

[The Buddha]

You check if you have a intake vacuum leak ?
Valve adjustment ? Though it would hurt start up more than riding at first.
Cool.
Buddha.

[SpanishBob]

How would I check for a intake vacuum leak? I did check around the intake boot between the carbs and engine. But we couldn't find any leaks there. I was riding the bike as my DD so I don't think the valves would need adjusting.

[The Buddha]

Valves need adjusting with wear, so a ridden bike will need valves checked every 3.5k as it gets to 30K mark.
A bike that's sitting will have the same clearance as it did when parked. You're confusing it with carbs needing cleaned

Intake leak - check with wd40 @ idle. See if it revs up or smokes white out the exhaust.

Cool.
Buddha.

[SpanishBob]

Would the valve explain the sudden lose in power? It happened when I was driving it. We check with the wd40 like u said and there was no smoke or rev up.

[iamhiding]

Would the valve explain the sudden lose in power? It happened when I was driving it. We check with the wd40 like u said and there was no smoke or rev up.

like buddha said, high idle indicates an air leak on the intake side of things.

by all means i could be wrong but as far as I'm aware valve clearances being massively out cause bikes to rattle so I'm fairly sure it would be evident that something was amiss there. most bikes could do with the valves being seen to and it doesn't really cause any symptoms like that.

i know you've already done it but spray the carb rubber boots with wd40 on the engine side of the carbs and spray the air box boots onto the carbs. if there is a leak it will rev high.

check the vacuum line to your petcock as well.

another thought and this is a long shot is that the vacuum slide that controls the lift of your needle in the carb could be stuck partially open due to the cap not being sealed or being ripped. the carb balance might be massively out for no apparent reason. both are long shots but id recommend inspecting the carbs and cleaning them because they're out anyway lolz thats more or less the next step after a quick air leak test anyway.

hard to say anymore than air leak without having the bike in hand, can't see any other reason for high revving and power loss other than a sticky choke.

let us know how you get on

[SpanishBob]

Well I got fed up with the bike and took it to a shop to have them diagnosis it. They said I have a bad frame mounted fuel petcock. The vacuum won't hold the seal and it leaks gas slowly into my intake. Then it won't allow free flow so that's why I don't have the power I should like normal. What do you guys think?

[The Buddha]

Maybe, I've seen that happen, but are you sucking fuel into the vacuum line ? That could be also happening.
Cool.
Buddha.