94 vmax 600 running like crap, possible fuel pump issue?

Is the air box and foam clean? If it is plugged even a little it will choke it out for sure at higher rpm
 
I had kind of this issue with my vmax 500 last year. After fighting most of the winter with carbs, I finally figured out the rollers were toast on the primary. Mine has stock jets in it and I find the plugs are usually black, as Yamaha seems to have played it pretty safe on the twins.
 
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I had a 600 once awhile back and it was doin the same thing you described.. It turn out to be the rollers and the bushing in the clutch cover...changed the bushing ,put new rollers in er and run like a raped ape!
 
yammy said:
I had a 600 once awhile back and it was doin the same thing you described.. It turn out to be the rollers and the bushing in the clutch cover...changed the bushing ,put new rollers in er and run like a raped ape!
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We just replaced both bushings in the primary and the rollers look good.
 
clutch weights look good and I have not sharpied the sheaves. How would a problem with the clutch cause it to dump too much fuel in one cyl?
 
A couple of bucks said:
Is the engine running ok up @ 60 mph? Just trying to figure which direction the focus should be on.
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It idles great but runs kinda rough up to 60. Also...it runs a little better on the colder days. On a 20 degree day it would hit around 60, at 10 degrees he could get it up to 75 until he ran out of room and it ran alot better.
 
I know you said you cleaned the carbs, but did you pass anything through the jets like a torch tip cleaner? If you don't have a torch tip cleaner or if it doesn't fit, you can always remove the jet, strip some stranded wire, push as many strands as you can through the jet, then twist the strands and run the jet back and forth along the twisted stranded wire. Also I didn't read if you tried changing or swapping the plugs.
 
brethren said:
I know you said you cleaned the carbs, but did you pass anything through the jets like a torch tip cleaner? If you don't have a torch tip cleaner or if it doesn't fit, you can always remove the jet, strip some stranded wire, push as many strands as you can through the jet, then twist the strands and run the jet back and forth along the twisted stranded wire. Also I didn't read if you tried changing or swapping the plugs.
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I did run a wire through the jets. we tried 3 different sets of plugs now. We're going to throw on a different set of carbs to see if that changes anything.
 
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