[Joes bike]

Hi group! I need some help. brought this bike (95 zx600r) about 3 mo ago. It ran fine until one day it started bogging. So I cleaned carbs,sync them, rejetted to 150 and 155 (had 180's stock is 142)new needles and springs (called dynojet,they said the needles wern't theirs), new plugs. Also checked fuel pump output, coil and wire resistance all check good. No change in performance......but here's the kicker I put tape over most of the intake scoops and it runs great. I also checked the intake boots for leaks or cracks. same with vacuum slides. Also compresssion checked 165-180 psi. All emmision stuff has been removed, has a micron can, bike has 24,000 miles on it.
Anybody had this kind of problem.....please help, thank you.

 

[ginofultano]

if you put tape over the intake, and it runs better, then it sounds like the bike is running lean. what brand jet kit did you install? what air filter are you running? i think you might want to rework your jet kit using the guide lines in this link. http://www.factorypro.com/tech/carbtune,CV,high_rpm_engines.html

 

[Joes bike]

hi, thanks for the reply. Yes it would seem that it's running lean, that's the puzzling part....it has the stock air filter/box on it. I also put the stock needles and springs in it.....it may have had microns jet kit in it, I called them and left a message, no response as of yet. One thing i found out lastnight, checking the valve clearances all the exhaust valves are less than .002" (should be about .012") but that would cause it to start hard, but it starts as soon as you hit the button. Also I noticed the vacuum slides show alot of wear on them, even though they move freely....I wonder if it is the fuel pump? any other tips? Any body have a set of carbs laying around or a fuel pump.....thanks