top end assistance needed

[parts eeter]

I recently purchased a 400 ex decked out in aluminum,with new wheels and razr 2s and just about everything I would ever want on it already except shox.The engine runs great but as told by the seller needed a rebuild and he gave me the new parts and here is what I have been given with my quad.
Piston=Wiseco 88mm 11:1
Cam= Magnum Part # AT-09136 Stage 2
Gaskets=Magnum top end kit std bore Prt# AT-10003T
I am ready to tear it down as its using massive amts of oil now and I dont want to let it get low and blow it.So my questions are as follows.
1.Is this a good piston to use as I have had bad luck with Weiscos in my jet skis?? If an increase in clearance is necessary I can do this if needed during boring process? Otherwise I will setup to man recomendations.
2. Is it stupid to use the stock valve springs with this cam and piston combo?? I am concerned about coil binding at full lift and the cam says I have to clay test engine to verify adequate clearance.I think this is a pain and really dont want to build my engine,time it and roll it over with clay on my piston because well I am really busy and dont have that kind of time to spend on it.So if anybody has used this combo without any problems let me know.I would really like to just take engine apart bore it and rebuild it with the new cam installed at factory timing of course minus decompression parts and be done with it.
3. I have rode a 440 ex before with a 13:1 piston and the same cam and it ran like crap.Was this just a crappy install or something because my oil smoker with jetting and bolt ons was faster by far.I am worried about this because I have ridden several ex quads and never really wanted one until I rode mine and was like wow it runs great!!! But it burns oil and this is the stuff I have been given and we all know the freebie factor is BIG!!

[parts eeter]

I will not be installing a rev box and I have never noticed valve float during aggressive riding. Also head will be intake and exhaust matched and smoothed.Thank you.I really do appreciate any time spent.

[POW 352]

well i like using wiseco pistons, as for the cam im pretty sure u just have to grind a little spot on the top of the head just set it on the top all braced with the bearings and spin it to make sure it doesnt hit...um i think valve springs might be good to upgrade with some setups its necesary to replace the valve springs at the end of every season anyways...but everthing else should work fine...wouldnt worry about the piston hitting the top of the engine unless you have a stroker and a stock piston..

[parts eeter]

thanx but not the info i was looking for.anybody else?

[underpowered]

1.I am not a fan of wiseco, i like JE pistons or Ross. I run JE in my 400. a wiseco will be fine, but teh compression ratios are not at all accurate.
2.the Magnum stage two is similar to the Hotcams stage two. It is fine with sotck valves and springs. no problems at all.
3. It is all in how the motor is built and broke in. i have never been impressed with a 440, still have yet to find one that beats my 426. The just arent that impressive in my book. if the motor is broken in properly it will run like a scalded dog, but if the bore isnt right, the motor is brokenin wrong, or many other facts will cause it to wear prematuley and not run right. a 13:1 440 prolly wont rev very quick but should have tons of low end. i love my 11:1 426 as it is still very torquey, but revs quickly as well.

[parts eeter]

Thank you for your time as it is much appreciated.You have taken my fear of spending money and time on a rebuild and losing power away.I will proceed with getting the cylinder bored and do a gsket port match on the head and install my freebie cam and be happy.I cant wait to ride my ex with my new built engine and 450r front shocks.I have had this quad for about 6 months and only ridden a tank or 2 thru it cuz the motors rings are shot and I have been so busy.Its been in storage and I havent even seen it for 6 wks!! any other recomendations are appreciated.Thanks again,Shaun