[joeschmoes]

I recently traded for a 04 450R. At high RPM it cuts out. It sort of acts like it is starving for fuel or air. According to the guy I got it from it has a 486cc big bore kit, 13:1 comp piston, etc. I'm not sure what else. It does have an HMF pipe and silencer.
It has extremely high compression. The strongest I have ever seen, it's actually insane.
Any pointers would be greatly appreciated.

 

[Saber6]

Do you think your hitting a rev limiter? How high rpms-speed are we talking?

 

[Redracer]

The Rev limiter on these machines doesn't feel like it's cutting out, it feels like it's slipping.

You are running race gas right?(or at least higher octane than what pump offers) Does it do it always of just when you stab it open? If you ease into full throttle does it fall flat?

 

[tomgodd]

RED is Right the rev limiter is odd on them?

 

[Saber6]

I was thinking it maybe had an after market ignition.
Do after market Ignition systems have a rev limiter?

 

[TRX2fiveO]

I have aftermarket on my quad and I haven't seen where there is one but then agian I try not to cramp it at those high of a RPM either.

I was thinking it maybe had an after market ignition.
Do after market Ignition systems have a rev limiter?

 

[Redracer]

Aftermarket CDI boxes usually add another 1000rpms to the rev limiter. I believe that the TRX is set to stop climbing at 9200 rpms but it starts to go into a double spark condition at 8400. An aftermarket will increase it to about 10200rpm limit and you lose the double spark.

 

[TRX2fiveO]

That's a pile of RPMs lol I'm not pushing it you will also risk floating valves.

Aftermarket CDI boxes usually add another 1000rpms to the rev limiter. I believe that the TRX is set to stop climbing at 9200 rpms but it starts to go into a double spark condition at 8400. An aftermarket will increase it to about 10200rpm limit and you lose the double spark.

 

[Redracer]

The YFZ hits near 10500 STOCK! 9200 is plenty.

 

[tomgodd]

Thats alot of revs!!!!