Just bough modded kfx450 need help/got ques

[twincat800]

I just bought this quad has the following upgrades: DASA Full Exhaust, Stage 2 Hotcams, Larger coil, ported and polished head (dont know where from), Je 12.8:1 stock bore piston, Power commander3 and some sort of aluminum intake box (looks good, custom all aluminum but prob not good for power), dyno tuned and air fuel waves between 12.7 and 13.2 (so it seems ok). 1st ques: Quad felt good and powerful but after riding a little while for sure lost power, do you guys think the exhaust making the aluminum air box couldve signifacantly couldve slowed the quad down (the air did get a little cooler if that helps)? By slowed down im talking having trouble beating a friends stock 09 yfz450 with baffle out and lid off. 2nd: for having all these mods it seems like it should be faster.. i have a dvx400 built (47hp 31tq but dynos read different) but technically not as built as much as this thing and it just seems like it should be faster.. a guy with same mods but stock piston and FCI intake says he got 51hp and with these mods that what I would honestly expect but it doesnt quite feel like it?My problems could just be my intake not being as good as the FCI which im sure i will eventually get but let me hear everyones input on what i have for now. One last thing, after shutting it off the fan did come on after about a minute maybe? and stayed of for what seemed like a long time, maybe running too hot, idk, but the bike did run very good and revs very fast but just seemed to lack the power i would expect, all help is appreciated!

[hondaracer_34]

With those mods your quad should be insanely fast. Sounds like you need to mess with gearing if its revving out fast and get it dyno tuned again if you can, just to make sure the quad is tuned properly. Go to this site www.kfx450hq.com , its a Kawi 450r based website and will give you ALOT of info.

[MtnEX]

Very likely to be gearing.


And power loss with heat can be several things.

Yes I would say the aluminum box is making hot intake air... aluminum is a heat sink material... meaning it transfers heat like crazy... That's what they use for radiators, heat sinks, coolers, etc...

Heat shield it, insulate it, or change it...

[Hetrick Racing]

We run the Fuel Customs air box sys.
Hands down it is the best on the market!!!
Also I would have numerous maps for the mods you have, the best way of course is to get it on my dyno and make one but im sure I could get you close.

[twincat800]

I did go with the FCI intake with the box. So now this quad has FCI intake, Ported head, stage 2 hot cams, je 12.8:1 compression, full Dasa exhaust, and dyna coil. Didnt tune it with the FCI intake yet but i raced my brothers 2009yfz with full pipe, and MSD ignition and thats it>>> we were basically even if anything i would barely get ahead on the top end. He made 47hp and 31tq which is a lot for what he has but i should be blowing by him. Later that day my exhaust was shooting white smoke (yipeee) took it apart and looks like the seals on the valves are no good. After i get it back together and if its okay im going to dyno/tune it and hopefully gain a ton of power..