450r sputters mid to topend

[450rheaven17a]

i have a 04 450r i have not rode it for a year. it started right up and seemed to run fine till i gave it alot of gas it sputters and surges at mid to topend. so i cleaned the tank,carb twice, plug,new airfilter. still does it!!! any help would be appreciated!!!!

[honda300EXtreme]

sounds like your mainjet is off... i would check your plug..


is sounds like your a bit rich..

[450rheaven17a]

this quad has never missed a beat. i totally disassembled the carb again. definatly not carb. is there any sensors that go bad or low level oil or water sensors. almost like the rev limiter comes on too soon. please help!!!!!:mad:

The carb needs to be cleaned. You need to remove it and take the bowl off. Take out the main jet and pilot jet and clean them out. you might need a paper clip or a pick to clear out the small holes in the pilot jet. That should fix it. Also drain the old fuel and put new gas in it.

[trick250r]

trx450r racers right take the carb off, clean it and the jets and you'll be fine

[d3ktrix]

Guys he said he already cleaned the carb twice.

My friend is having the same problem with his 04 450r right now.
He's been trying to fix it for a week or 2 now.

He was racing, bike was running perfect, then in the middle of the last lap this problem started.

Anything over half throttle and the bike cuts out / pulses real hard.
Its almost like a low RPM, really extreme rev limiter.
Its not the fake type of rev limiter u get from rich jetting, it is much more extreme then that.
It almost sounds electronical.

He cleaned the carb multiple times, changed plugs, filters, coils, took his kill switch off, and many other things with no luck.

[450rheaven17a]

thanks frank this is brian O from ftr. I had every peice possible off the carb. all jets air screws choke etc. im VERY mechanically inclined. its spotless! tank and airfilter and box also spotless. the discriptipon that guy gave is exactually whats going on.any other ideas.

brian 727 742 1771

[pro-rider46]

i had the same problem, it was jetting over all. all of a sudden my jetting changed and i figured it ran great for close to a year it cant be jetting. but when i put my exhaust on and rejetted it ran like a raped ape. this can be other things though like the stator, valve clearence. and carb issues ( whitch cant be it. cause you cleaned it.)

good luck

[d3ktrix]

My friend figures his out, he replaced his key switch and the wires going to it, bike runs perfect now.

Seems really weird to me, esp since before this problem started he had no key hooked up at all, only a kill switch.

[warriorxcr1]

my friends quad did the same...... ran great then sputtered. then got worse.

turns out some dirt got through... ruined the valves and ended up making the piston blow.

check the clearences!

[450rheaven17a]

found that the bottom of the cdi box is cracked. hope that will fix it!!!!

[450rheaven17a]

I put a new cdi box in and no change.I have no clue what to do. i had a dealership mech clean carb just to be sure.he said it was spotless like i told everyone. any ideas PLEASE HELP!!!!!!!!!

[400exrider0004]

have you drained the fuel? I was at a track and all of a sudden I started sputtering and would get pulses of power. I ended up having water in the gas from it sitting to long. Make sure fuel system is clean.

[450rheaven17a]

even the dealership cant figure it out. they have 12 hours in it and can only say there leaning toward electrical. should have kept my 250r's.

[450rheaven17a]

3 shops and still no answer.BULL***T !

[CSR400EX]

has any of the shops checked the stator or test it at all???

[450rheaven17a]

A complete 2005 electrical system was swapped out.same thing. I guess im gonna have head looked @ next....

[3x440ex]

Dude all I can say is mine was doing the exact same thing...it ran great, I let set for the winter and when rode it in the spring it had no mid to top at all just sputtered the whole time like a really early rev limiter. I drained the fuel and cleaned the carb (pulled all the jets and blew them out) twice, but that didn't help. I ended up putting everything back to stock. I put the carb back to the stock settings and put the baffle back int the pipe and closed up the airbox. The only thing I didn't change was the cam, I still have the Hot cam 2 in. For whatever reason, that fixed it. The only problem I have now is I have no low end at all with the cam I'm running.

[CSR400EX]

the decompressor mechanism on the cam could be bad.