Want more Power

[SporTrax400]

I have a 400ex with supertrapp exhaust, with the k&n and rev limiter and want to beef up the motor. Right now I have my motor apart and want to put in a cam and possibly a 416 or 426 kit. I am not to sure though. I do a lot of riding at the dunes and racing up the hill. And durning the summer I trail ride. But I want to increase my hill shotting at the dunes. Right now I am in 3rd gear maxed out while racing up the hill with a front 14 tooth. I want to increase my mid range.

What should I get? I am not to concerned about the cost, I just want something that is reliable.

What kind of Cam? Is the 416 or 426 the right way to go?

Thanks,

Greg

[flaneledholes]

For the dunes, I wouldnt reccomend the 426, because your engine will run too hot because of the thin sleeve...I would reccomend putting the 416 kit in, then when you goof up the motor or want more power, keep upping the bore... I think if you put a cam on, it will help alot, talk to some other people about what midrange cam to get but start off with a 416 and a cam or what my reccomendations are is that you just get a higher compression piston and the cam and get a bigger carb instead of doing the 416... I would get the 39 fcr(beacuase you said cost is not an issue)$400-$450... So that would leave you with just as good and I think an even better power increase and you havent tampered with the motor, then just keep doing everyting else like porting and so on until you want even more power and then go into the motor...

PS: I would run without an air box and put an outerwears wrap on the K&N(this is what I do)...

[Castor-426ex]

yep i too think the 416 is best bet unless you want to fully invest it all into a 440.. if you do look at additional cooling...

some people dont think the 416 has enough wide open pull for the sand...

good luck

[SporTrax400]

Thanks for your fast replys.

What is all involved in putting a 416 kit in my quad?
What can I do on my own?
Who/Where can I get this kit from?

Thanks Again,

Greg

[crashinmatt]

to put a 416 in ur quad all u have to do is get a piston and bore the cylinder .80 over. but if ur goin for a kit then there r a lot of different companies out there (LRD, CT racing, Sparks racing to name a few). or u can get kits from other places, like marcums for instance. but if u wanna do it all urself, u need to get the piston, cam, top end gasket set, and a place to bore ur cylinder.

[SporTrax400]

If I buy a kit from Marcums will they bore my cylinder?

Greg

[crashinmatt]

im not sure on that one, but i know people on here do. i know some of them have that particular kit. so hopefully one of them respondes.

[JabberJaw]

Put a 440 in it and just buy a fan from the wrecking yard.

[400ex99]

yes marcums will bore your cylinder, he can also port and polish if you like, a mild port and polish is not expensive, he is good to work with,, he needs your new piston, cylinder and head.:blah

[Dave400ex]

I think the Best would be the 426 kit. It would still Rev out fast, but yet still have that Torque. I know a lot of Companies are now running them because they make a lot of Horsepower when done right. TC`s Tom Carlson really likes the 426 and had one make 42 horsepower on a Dyno. Get a JE 426 Piston, TC Cam, TC Valve Springs, Harden Rockers, Head Ported and Polished, and a 39 FCR Carb.

[SporTrax400]

All right, thanks for all your help. Has anybody done a review or a ex tech on motor work. I might try to do one for the sight.

Thanks,
Greg

[honda400exrider]

i dont have too big of a brain, lol. but when u bore your quad over, i would reccomend beefing up yer clutch, like new springs and plates. especially when u have to constantly rev out yer gears. both my friends with motor work have had to replace their clutch. but im prob off, and sum1 with more experience would tell u all the technical bs.....