need youre help!

**KEtwoXT** · #1 9 Jun 2009

so i would like to know why my xt600wont rev out to 7000rpm.
to help you it seems to have great low end power but as the rpms get past 3500 it seems like it looses hp enough to were it wont rev past 5000rpm...

thanks in advanced -Justin

**samson** · #2 9 Jun 2009

just check the air filter , change the spark plug . maybe its the combination of vibration end a loos contact . if you rev it up do you loos electricity

**samson** · #3 9 Jun 2009

check also your battery clamps ,it happens often. if they are loos together whit the vibration you have a bad contact

**BlackDogZulu** · #4 9 Jun 2009

Could be any number of things, to be honest - fuel problems, spark problems, even binding brakes [1]. Tell us a bit more about the problem and narrow it down a bit. Does it start well? Idle OK? What is the problem when it loses power - gradual lack of urge, or a misfire? Exhaust smoke? Have you checked plug gap, tappet clearances, compression? Good or poor mpg?

[1] To illustrate: I had a mate with a Honda 250 that wouldn't go above 50 mph. Every time he got up close to that speed, the bike would start to struggle, almost as if the brakes were on. He had checked everything, and spent pounds on replacing possibly faulty components. The clue was that his front brake went bad at the same time. On inspection, the front pads were glazed. It was a cold British winter, and the bike was wearing those handlebar muffs. I told him to go for a run and, when the bike started struggling, to straighten the fingers of his right hand. Sure enough, the bike carried on accelerating up to 70 or so. The wind had been blowing the muff back onto the brake lever, creating more drag the faster he tried to go. The lesson we learned from that: assume nothing, and rule nothing out.

**wolfzero** · #5 9 Jun 2009

ball park guess is that the secondary part of the carb is not functioning correctly

but as to why there are a number of things you need to check do a search for carb service/repair

**KEtwoXT** · #6 11 Jun 2009

Quote:

Originally Posted by BlackDogZulu

Does it start well? Idle OK? What is the problem when it loses power - gradual lack of urge, or a misfire? Exhaust smoke? Have you checked plug gap, tappet clearances, compression? Good or poor mpg?

well it starts ok, but when its hot it gets stubbern(like it will start then cut out then flood the carbs.) i just cleaned out the carbs too

and the exaust doesnt blow any smoke..

no misfireing..

havn't checked plug gap. but my spark is spot on.

never checked the compressoin but the kickstarter has alot of resistance

mpg is about right

when i have it in neutral with the throttle wrapped.... wont go past 5k

just seems to lose its power.

brakes cant be binded, it coasts perfict

halp!

**KEtwoXT** · #7 11 Jun 2009

oh and when the bike is ideling it likes to stall out the second you toutch the throttle.

and if you rev it up the rpm's dont always go down to idle the way it should.
i have layed the bike over cause i have locked up the front brakes trying to stop it..

**Gawain** · #8 11 Jun 2009

Bad hot starting is usually a sign of closed up valve gaps. Id also want to check for air leakage at the carb rubbers.

**BlackDogZulu** · #9 11 Jun 2009

Quote:

Originally Posted by Gawain

Bad hot starting is usually a sign of closed up valve gaps. Id also want to check for air leakage at the carb rubbers.

Sounds a lot like a weak mixture. Air leak somewhere, I'd say.

**KEtwoXT** · #10 12 Jun 2009

could it be that i have too much air?

cause the piece on the left carb has a huge chunk missing were the intake hose goes. not sure if it's sealing all the way..