Total Motorcycle Community Forums

I just replaced all 4 spark plug with new ones, I think the 3 of the old ones failed the spark test.

But once again back to the old problem, The engine starts ok and it idles at 1100-1300RPM OK. On neutral, I rev up to 4000-5000RPM it falls back on 1200RPM OK.

But when I drive the bike on 1st or 2nd gear when I rev to about 4000RPM after I pull the clutch, most of the time the engine dies completely before I can shift to next gear. Or sometimes on 2nd gear at about 3000RPM the engine sounds like its "choking" then when I pull the clutch the engine dies.

WHAT IN THE WORLD IS CAUSING THIS PROBLEM! I want to know how to fix this problem, I bought this bike about 8 months ago, and I havent got any fun out of this bike just headaches, bad luck for me that right when I bought the bike it went BAD. =(

Help would be greatly appreicated =)

Model/year of bike??

1991 Yamaha FZR600

not sure if you have checked or not, and I don't mean to insult any intelligence or anything, but have you checked the air and fuel filters?? If either or both are dirty enough, they can be to restrictive under load... ie: not enough to run with. Same goes if you have a wet air filter with too much, or too little filter oil.

I tried riding even with the air filter off completely, problem still there.

I tried to unplug the gas hoses and turn the key to ON and I see gas shooting out.

from my experimenting, the bike usually start to act funny after about 25MPH but when its on neutral with my bike standing still the engine seem to ldle and rev ok.

Time to start looking at everything on your bike.

Is the ignition timing correct?
Is the camgear timed to the crank properly?
Got good compression in all holes?
Are the coils weak?
Is the muffler blocked?
Got your foot on the brake?

.......

.......

I dont know how to check most of the stuff you named.

but I did discover one thing, my new spark plugs are getting black already. I heard black spark plugs means it's running too rich, how do I fix that problem?

after some tune-ups now my bike is running alot better now.

but for some reason my bike seems to run ok at low and high RPMS, during mid RPMS the bike will lag. The higher the gear the stronger the lag. Why does it lag during only mid RPMS?

Sometimes if the RPM is too high if you pull the clutch the engine will die.

How do you fix these problems? And how you fix the engine running too rich problem?

BuzZz wrote:Got your foot on the brake?

aahahaha!