engine help

[3traxrider320]

I will be sending my quad in to have the engine worked on (the dogs on the 3rd counter shaft are believed to be stripped and maybe replace the clutch.) This work will involve splitting the case... I was wondering if since the engine is apart, would i cost much more to bore out the old 400 to a 416, or should i buy a 440 kit, any reccomendations????

Thanks

[Predator36]

If the engine is apart any way - the cost of boring to a 416 could be from $35.00 - $50.00.

[deansfastway]

for more power you could have it sized out to 88 mm and it will be 425ccs then get a cam and some clutch springs and youre in business. Maybe check that cam chain too as they stretch and wear out.Mainshaft 3rd gears fall apart because theyre powder gears and are only hardfaced where the gears mesh. The hardfacing wears down and theyre will be puck marks on the loaded edges of the gears faces where the gears mesh . If youre quad has much time on it Id replace that gear its only like $45 and we replace them almost everytime we freshen a motor (wintertimes) I like to have the gears cryotherm treated to cold forge the metal and we beleive that it helps. I have seen some of these third gears come up through the cases on big motors after they explode , one time it hit the starter so hard that the starter bolts pulled out of the case That motor was trash , it was in a race quafd for awhile then it was on a quad in the sand with paddles. GOOD LUCK

[2 QuicK]

Since your engine is already apart and u have the money, y not? I would go with the 416. That's what i'll be getting this spring and from all the info that i have gathered that seems like the best bet. And while your boring it why not go the whole 9 yards: pipe, carb, high comp piston, cam, valve springs, and hard faced rockers:D One hint~SparkS:rolleyes: