Surging problem at 5500rpm

[carbon vmax]

hey guys

I have a 2001 vmax that has recently developed a surging problem at 5500 rpm when cruising in fifth gear. I have had the macanics check everything from O rings, rubber connections (for air leaks), checked the compression, disconnect the vboost, new plugs, cleaned carbs, synced the carbs, adjusted the needles inside the carbs as well as the floats. All done to yamaha manual but still the problem persists. (already checked the exhaust for leaks to)

I have heard of a vmaxer with the same problem. He said his rubber connections had nearly invisible cracks in them which opened up as the bike got hotter. Replacing the rubbers solved his problem.

I am going to order my new rubbers today. But would appreciate any feedback from you guys.

 

[tugla]

whats it exactly doing? can you run it past 5500, or this just when you stay at 5500? does it get worse when the bike warms up or happens all the time, maybe clutch issue? also ignition if you are having a intermittent issue. how is the fuel filter on the bike.

 

[Maxbailie]

I have the same problem,, goes fine if it goes through 5500 but has issues cruising at that speed,, feels like running out of gas,, seems to get worse once warm

 

[Maxbailie]

2003 vmax with only 5k miles on it

 

[[email protected]]

Try backing out the AF screws a bit. You wouldn't think it would make a difference at that high of an RPM but, it can.


A lot of times when at a steady cruise, you are using very slight throttle openings to keep your speed up. My best guess is that the needle isn't pulled out of the main very much in this condition so the A/F screw is more apt to make a difference versus a wider throttle opening.

 

[Rusty McNeil]

Mine did this before along with some other nasty habits. It was due to poorly seated jet block due to the too thick o-ring I used around the main needle orifice tube.