450r hick up

[motoguy450r]

i have on 04 450r when you get to half throttle it starts cutting out like its in the rev limiter, it does it through every gear wether the motor is hot or cold. we have replaced the rev box/cdi, ignition, carb, plug, and checked out all the electrical and it still does it. anyone had this problem or heard of it before. any ideas or suggestions would be appreciated. thanks.

Is the quad stock or does it have mods? Does it clear up at full throttle or get worse? Has it been sitting for a while? See if it will it run better with the choke on.

[tsi400ex]

I'm having the same problem with my bike too.

[440challenger]

jetted for lid on or off. if off is the lid on?

so its like hittin the rev limiter way to early like your clutch is still partially engaged?

[motoguy450r]

it is an o4 with a stage 1 hot cam, 12.5 piston, updated crank, 39mm fcr carb no air lid. head is all stock, motor has less than 1.5 hrs since rebuild, it has ran great up til now with no problems at all.

[motoguy450r]

it acts like its in the rev limiter at 1/2 throttle, it doesn't get better or worse at wide open throttle, it stays the same from 1/2 throttle on, valve clearance is good, valve springs are good, just stuck and can't figure it out.

[Doober]

sounds like something up with the clutch. when the last time you replaced them clutch plates?

Originally posted by motoguy450r
it acts like its in the rev limiter at 1/2 throttle, it doesn't get better or worse at wide open throttle, it stays the same from 1/2 throttle on, valve clearance is good, valve springs are good, just stuck and can't figure it out.

Does it do it sitting still in neutral or just under a load?

[d3ktrix]

Whats ur jetting?

My friends did something similar, it was his ignition switch if I remember correctly, though u said you replaced yous.

[motoguy450r]

i haven't replaced them the bike only has about 10 hrs on it, took it apart when we build the motor and everything looked ok, ikd probably pull it out and check it.

[motoguy450r]

replaced the ignition, it does it in nuetral and when under a load but it doesn't do it all the time just like 1/2 the time.

[d3ktrix]

What jets are in the carb? Sounds like a rich main jet.

[motoguy450r]

i don't remember what jets are in it, james at jpmx is taken care of it, we have changed carbs and it still does the same thing, his bike is doin the same thing too and he can't figure it out either.

[woodsracer144]

it did that on my 250r also, it would spoit and sputter after half, it was a wrong gap along with a carb that wasnt jetted right and i know the 250r and the 450r are way different. im sayin its in your carb some where... its a lack of fuel. or a lack of air or a lack of both i would say....

Originally posted by motoguy450r
i have on 04 450r when you get to half throttle it starts cutting out like its in the rev limiter, it does it through every gear wether the motor is hot or cold. we have replaced the rev box/cdi, ignition, carb, plug, and checked out all the electrical and it still does it. anyone had this problem or heard of it before. any ideas or suggestions would be appreciated. thanks.

Did you try a new boot for the coil or a new coil? If you don't have the correct resistance in the coil boot it will cause that.

Also did you see if there is dirt in the carb?

[Scro]

It sounds like something electrical to me. If the problem was in the carb it would do it all the time. I would check to make sure the connections are tight on the coil.

[motoguy450r]

the carb is clean and like i said i have changed the carb out with another one and it still does it, i don't think its a fuel problem, i'm leaning towards an electrical problem, mark baldwin said stator but in my exp. the stator either worked or it didn't.

[motoguy450r]

i agree with u scro, i think its one of those pain in the a**
electrical problems, probably something stupid like a broken pin connector or something, anyone know of any bad spots in these wiring harnesses or anything.

[Scro]

The reason I say coil, is because a buddy of mine had one of the wires on his come loose during a race. It sounded horrible when it did. It would still start up and run perfect off idle, but once you got going it would start spitting and sputtering. It sounded awful, and sounds similar to what you are describing. I ran over, put the wire back on for him...ran perfect after that.

[woodsracer144]

you dont have a map ing. like the vortex or anything like that do you?

[Jshep450r]

try fresh gas my friends bike does the same thing when the gas gets old

[motoguy450r]

gas is fresh as it can get and i changed it and made sure the tank was clean, no maping or vortex just a white bros rev limiter.

its either the clutch or electrical. pull out the clutch and check that out.

[tsi400ex]

I got my running again, you guys were right one of the wire going to my coil was loose. Motoguy450r, you should check your coil wire too. :) :) :) Thank You

[motoguy450r]

well the clutch is good, i've replaced the coil and wires and that isn't it either. idk i'll figure it out somehow.

[Scro]

If the coil is good, I would try a stock CDI. I've heard of aftermarket boxes causing problems.

[REPOMAN]

mine did the same thing a couple of days ago. i put the air box lid back on and it cleared it up instantly. probably not it for you but its worth a shot

[Scro]

Originally posted by REPOMAN
mine did the same thing a couple of days ago. i put the air box lid back on and it cleared it up instantly. probably not it for you but its worth a shot

If you rejet your carb for no-lid, then yours will run alot better than with the lid on;)

[REPOMAN]

yeah I just bought it and it has full fmf on it ANSI am not sure what to jet it at. And not really ready to start working on stuff again yet either