bore help

[tp300ex]

ok so i want to bore my fourwheeler to a 416 but have no clue wat to get if u could give me a list and a site to order from it would help alot thanks tad

[exrider008]

im doing the same thing so help us out.

[tp300ex]

bump

[GPracer2500]

Either go to a local performace tuning shop or get on Google and start searching. The items you need can be obtained from any of many dozens of sources. Don't forget to check E-bay--lots of new parts sold there for excellent prices.

At the minimum you'll need the piston (87mm is a 416) and new top-end gaskets. A service manual is also manditory in my book. It's worth having for the torque specs alone. Piston choices include JE, Wiseco, and Ross. Wiesco is popular--I slightly prefer JE. The piston should include rings and the wristpin.

Consider what compression ratio you want/require. Stay at 11:1 or under to use premium pump gas. I've found 91 to be marginal with even 10.8:1 w/ hard running. I'd guess 93 would be OK at 11:1 (and perhaps marginal under extreme conditions). Running a pump gas race gas mix is never a bad idea to eliminate detonation concerns.

I installed heavy duty head studs (source: GT Thunder) and had the top of my cylinder sleeve O-ringed (stainless steel O-ring). These mods add strength and longevity (far lower chance of blowing the head gasket). With a less than 11:1 416 piston those mods may not be necessary--I'm sure lots of folks don't do either.

I would also upgrade your cam while you're in there. Hotcams stage 1 or 2 seem popular. I'd go stage 2.

You'll need to take your new piston with you to the machine shop when you have your cylinder bored and honed.

So, that's not exactly a "how to" guide, but it should give you something to go on.

Also, see here: http://www.exriders.com/vbb/showthread.php?s=&threadid=221740