I have a 400exsplore 4x4 that i would like to rebuild,but i need some good tips.I really would like more POWER but not at the cost of relyablety.And shuold i keep the oiler or ditch it? If ditch what oil,and what ratio?High comp. piston? Exhaust?Head work?Jets? Anything will help.PLEASE!!!!!!!!!

 

A pipe will really wake up the engine, and with a Wiseco piston, not really hurt engine reliability enough to notice. Some claim a 5 HP gain, which may be true.
If you do ANY mods to the engine, a clutch kit will help get the power to the ground better, highly recommended. If nothing else, you can get the same performance with less engine mods, so the engine should hold up better given comparable performance.
If you REALLY want to fly, go with cylinder porting, high-flow reeds, a high-flow pipe, clutch kit, high compression head, and high-flow airbox kit. You will have to run premium gas (with the high compression head), but you will not believe the performance. Rode one like that once, hit the throttle, and about scared me to death. WAY more power/acceleration than stock.
As far as reliability goes, Ritter Cycle has about the best reputation I know of for RELIABLE power kits for the 400 engine I know of offhand. Check out rittercycle.com, see what is there, and give them a call. What I like about Rick (Ritter) is you tell him what you are hoping for (how much power gain, how much reliability, cost, etc.) and he will 'customize' a kit that best suits what you are looking for.

 

Buy you some new blue plastic to make it look real nice and perty. then get u a yfm660r engine and slap that baby in there. oh yeah

 

yfm

If i put blue plastic on that ugly beast and made it nice and PRETTY i would be a big puss like afriend of mine and not want to get it in the down and dirty!



Farmr

Thanks for your info. i called rick yesterday and he set me straight.I'm going to go with the stage1 kit.Rick seams to be alright and he knows his sh*t. I'll get back and let u know how it all turns out.



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96 400 exsplorer
99 500 scram
02 250 ex
98 250 recon

 

TX, I have bought stuff from Rick 2 times already, and both times he was both knowlegable and helpful. Honestly, I don't know how the man has time to get all his work done, as willing as he is to give 'free' advice over the phone to whoever needs it. There may be places that can get a few more HP out of your machine, but Rick seems to really have gotten a reputation for reliable horsepower in a bolt-on kit.