6k sputtering but not the carbs?

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mvk24
Lookin' Around
Lookin' Around
Posts: 69
Joined: Wed Oct 16, 2013 10:25 am
Location: NY

Hey guys update from my last post
I got a brand new petcock as suggested by Radare, also got a new set of carbs from someone in PA. rebuilt and installed them. set floats heights to 10mm off the surface, put the 20 pilots in them.
I synced (using the bb trick) and was able to tune each carb to anywhere from 490-515 degrees at idle with a fan blowing on the motor.

Before I did all of this we had an issue with sputtering and lose of power as soon as I hit 6k rpms, however you don't feel or lose any rpms when in neutral its only when moving... I thought this was a carb issue but now with an entirely new set of carbs it must be something else. I noticed the crankcase breather looks cracked but that is not a vacuum line correct?

all of the boots are new with no cracks

the fuel is no longer gurgling in my vac line with the new petcock but I do notice air bubbles in the fuel line (I use clear hoses).

does anyone have any idea where to start? i'm starting to think its something in my engine which I don't have the time or space to open right now so it may be time to take it to a shop if we cant figure it out on here. I think the only last ditch stupid things to do would be new spark plugs, new vac line just in case.

Problems - Sputtering and lose of power at 6k but only when moving. Not in neutral or when clutch revving.
Air bubbles in fuel line
Also it looks like there should be clasps on the air box boots that go on top of the carbs that I don't have.. are there normally and I should track them down on ebay?
the idle is very rough all of a sudden and drops on it own or hangs at 2k after I hold it steady for a moment but its tuned to near perfection so I'm not sure where its coming from.
Bike only has 9k miles on it and sat for 14 years before I picked it up 5 years ago. was running great until 2 weeks ago when all this started

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