wont rev all the way up to top (02 sportsman 700)it just wont rev up to full throttle. Id say if WOT on these is around 5000, i probably get to about 4000 and then it just wont go higher and sounds like its hit a limiter.

I have an 02 sportsman 700. since I have had it( few years) I have upgraded with a second hand kokusan stator and cdi , new water pump impeller, put on new rings and head'n' base gaskets. New muffler (aftermarket),new wheel bearings and brakes new fuel pump and put in a moose carb rebuild kit.

seems to be hit and miss with running ok , sometimes this summer would start and run like a top, then not so good expecially after a little while. seemed like the old symptoms prior to ignition upgrade were recurring. it would not accept throttle after being ridden for an hour or so , it would start bucking .
First i thought it was rings, then the ignition kit. I replaced them both and things were great ....for a bit.
Then it came back spiraticaly
in the summer it would start bucking when hot, but not every time I ran it. I think it may be hot fuel in summer after the engine heats up the tank . at least that maybe a the problem.
I thought this may be a fuel issue so I replaced with a new cheap fuel pump.
found prob still happening when hooked to an aux gravity fed fuel source. but thought maybe it needs the extra push from the pump

I havent had a chance to see if the bucking will still happen because due to hot fuel because
im stuck with the WOT problem that I am here for advice for.

The problem im having currently I am having trouble figuring out.
It wont rev out all the way. it sort of hits a wall before the top .
seems like fuel issue but not sure at this point.
I cleaned out the carb, thought it was rich, so lowered needle.
made it worse. so adjusted floats to spec, and needle back to mid pos.
seemed good.
EXCEPT.
it just wont rev up to full throttle. Id say if WOT on these is around 5000, i probably get to about 4000 and then it just wont go higher and sounds like its hit a limiter.

what I mean is...

i get to the point where its all main jet and it seems either rich . kind of like its just unable to rev that high, like it hits a limiter sort of.

so I change to smaller jets (was a 157.5) 152, makes it a happen a bit sooner but doesnt fix it, so I figure it must be running lean..
so i go to larger jet 170.
and it still happens , a little later maybe but still happens.
like its hitting limitter. Its not a cough or a bucking ,
I wonder if the exhuast cant get out? maybe the valves ?

so going leaner or richer doesnt seem to fix it, going richer makes it happen at a higher rpm and leaner makes it happen at a lower rpm.

and now im @ a 170 main jet, and stock is 152 . it only happens once im past 3/4 throttle.

most people run 157.5 which is what it was running all summer with no problems up at WOT.
so its something that has changed or is intermittant.. Ive had the carb apart and cleaned a dozen times recently so It really shouldnt be dirt.

I have spark on both sides.
I have new fuel pump.
the floats are adjusted to 13.5 mm (spec)
choke on or off doesnt affect it.

one thing I noticed today was that if I hold throttle steady half way or whatever, it doesnt stay still. it goes slowly up and down a bit.
and when I hold it at WOT and it does the stuttering not reving out thing , it will come down to idle and stall. starts right up after but wont come down to idle and stay running.


Does anybody have any ideas?
been through this before?
could it be a compression issue? (seems to pull really hard and I changed rings last winter)

Pls let me know your thoughts
cheers
T