overheating??

[veddersbetter]

Alright.....I need some help here:( I have a 2000 440 EX(startin to wonder if the dealer was lyin that its 440) with K&N filter,no airbox lid and Yosh Pipe. Im not sure how its jetted or what comp. piston is in it. What I do notice is that when I first got it I couldnt beat any other 400 with pipe and filter. I figured it was the 22" tires that were on the back. ...plus the wheelie torque wasnt quite there like the other 400s. I traded the Stock Ohtsus on my friends quad and gained alot......raced a quad I couldnt beat with 22s and ran about 3 quad lengths ahead by top end, and gained back the wheelie factor. So I thought Great...problem solved. After that I bought new 20" fast trekkers. I never had a chance to ride with the 20s in the colder weather but now that its a little warmer out....my quad heats up fast(15 minutes its HOT) and will not even keep up with the 400 I beat 10 times in a row a couple weeks ago. I can also tell it doesnt have the torque it should. Would you think this was a problem with jetting now that its warmer? Or is there anything else it could possibly be?
Thanks ahead for any response
:confused:

[Tommy 17]

i noticed that no where in there that u said that u had a cam... without the cam ur really not gonna pick up that much by just having the 440 kit and pipe... it will give u alittle bit more but not nearly as much as the piston and cam combo...

[NJ300ex]

it shouldn't heat up that fast. Your jetting is probably way off.

[RED121572]

You bought a 440EX from a dealer? Thats why I dont buy used cars, "You never know what your gonna get."

My two cts worth is get a shop manual and start wrenchin. Find out EXACTLY what is inside your thumpers motor and carb. I know it sounds like alot of work and it is, but i personally would go that route. Your cam might be stock, your valves might be loose or a million other things....so get that tool box out!!

Good luck with it bud!!:)

[oynot400]

I agree with 400ex21, to get the full affect of the 440 you need a cam to help let it breath. One guy that I ride with from time to time just has a 440, no cam. He has more low end grunt but mine has way more mid and top end power.
As far a getting hot, check your jetting. I have noticed that mine it running better now that it is warmer. With the extreme temp changes in the midwest you will have to do some carb tuning twice a year.
Hope this helps...;)

[VegasEx'r]

Red & 400 are right. You need to get into that bad boy & see how it's jetted & what-not. You also need to get an aftermarket cam

[veddersbetter]

thanks guys.....how would the xr400 cam work in my quad?

[VegasEx'r]

I think with a 440, the xr cam would be too small. I'd look for something a bit bigger, maybe from GT Thunder, TC Racing or maybe the HRC copy cam from xr's only.

[RED121572]

I just tore out my XR 400 cam and stuffed in a WB's. Im very happy with the results. I personally think the XR cam isnt worth a pot to pee in.