660 with no power

[foodaguard]

My raptor has no power and ive checked timeing and compression. It had great compression and the timeing is fine. What could be my problem.

[Livingmylife93]

Your jetting could be off, clutch may be slipping.

Could be alot of things, can you be a little more descriptive?
How does it run?

[4stroker]

check the spark plug for weak spark or fouled out,head gasket maybe blown?

[Peelz]

buy a 700?   

ba-dum crish! thank you, thank you, I will be here all week. 

On the real:
A bit more info is needed.

I assume air filter is clean? Is it sputtering when you open up throttle? Could be a number of things:

parking brake sensor shorting out. (this makes it think p.b. is on, and engages rev limiter, retarding ignition)

same for clutch and neutral sensor.

Or a carb jetting problem. (hope not)

My advice: unplug parking brake sensor (easy one to rule out.)

Follow wire from PB assembly on clutch perch to down beneath left (driver side) fender, to a two prong white plug. Should be right above headlight... Remove it and try it. This opens the circuit, disabling the P.B.

Just a quick one to rule it out. Then go to the harder stuff.

[foodaguard]

The Pb sensor is already un pluged. I also thought about the clutch abd checked and its fine. Air filter clean and dosent sputter at all. New spark plug with strong spark. I took it to sand mountian for a week and it was running fine no problems there. But the i got beat by my cousin on his 400 ex on all hills. It seams to have less power then my old 400 ex. It also would only wheelie in first geat and didnt have the power to pick up the front end at all. When i was there on my 400 it would ehelie a hell of a lot easer ans it was in serious need of a rebuild.

[Livingmylife93]

Is it blowing smoke?

[Peelz]

OK, gotcha.

Mine would wheelie no prob in second. On accident. My grab bar will attest. There is a big power spike around 5000 rpm Wheelies just happen in first and second. 3rd is tough.

Not sure what to tell you.

[foodaguard]

No it isnt blowing smoke. once it revs up it dose have a little more power but not much more.

[NateDiggity]

Whens the last time you checked/adjust your valves??

[Flynbyu]

Carb boots sealed?

~Brian

[foodaguard]

I check the valves after every time i go out cause i usualay go for a week or so in the sand. yah the boots are sealed

[Flynbyu]

Spark plug?

Spark plug wire?

~Brian

[Peelz]

what are your mods?

[Flynbyu]

There's no way you should be loosing to a Honda 400. You should have him by ten lengths.

~Brian

[foodaguard]

There are no mods. When we raced up comp hill i was ahead of him by about 3 quads  then by the middle of the hill he would pass me and bead me by about 4 quads. he said he was pullin the hill in third and was in second at the top. When he passed me i was haveing to shift in to first to make it up the hill.