probs with my 400ex

[GObigORgoHOME]

it is over heating and its loosing oil fast and white smoke is shooting out the exhaust.

[TCracin440ex]

piston rings are fried bro...bottom line there aint no fixin that w/ an oil change or anything....you gonna have to tear the motor down and put new rings in and possibly a piston too depending on how bad they are...might ahve to have the cylinder rehoned too

[GObigORgoHOME]

how much you think that woud cost

[TCracin440ex]

i have no idea ive never had to do a topend rebuild on mine.....

it all depends on if your doing the work yourself, or your having a mechanic doing it...

and its also gonna depend on if your gonna need a new piston or not

[GObigORgoHOME]

thanks man. this sux ***

[TCracin440ex]

im looking right here on yamahaoftroy.com the piston rings are going to be 37.55

and a new piston IF YOU NEED it will be 61.58

if its smoking that bad like your talking about your proally gonna need your cylinder rehoned too depending on if its scared or not....

[TCracin440ex]

http://216.37.204.205/Honda_OEM/HondaATV.asp?Type=13&A=92&B=16


there you go...you can find everything you will possibly need right there on that page

[GObigORgoHOME]

thanks

[GObigORgoHOME]

thanks

[GObigORgoHOME]

thanks for your help

[TCracin440ex]

your welcome bro...no need to thank me just helping out a fellow quad rider

[bigbore660]

I just did my top end. I went with a Wiseco kit from magic racing. I think it was $125 for piston, rings and all the gaskets. I got the 11 to 1 compression which you can still use pump gas. (93) I also had to go one size over. When you take the top end off, take it to a reputable shop so they can measure tollerances and tell you if it needs boring. It will cost you one hour labor usually. Mine was $65. but then you have a fresh motor. Well worth it. Don't forget to use a torque wrench when you put it back together.

[2001300exguy]

C&D:o

[GObigORgoHOME]

did you gane much power by boring it out

[bigbore660]

I don't know, I actually bought it like that. The guy I bought it from sucked a bunch of sand in the motor and it chewed up the top end. But I do know from 5 years of racing and countless rebuilds on a 250R that it will give you more power by boring it out. But if the tolerances are ok you don't need to bore it. If your cylinder is ok it will bring back the power with a new piston and rings. Or maybe just new rings in some cases. You have to measure them to know for sure what you need to do.

ya i had the same problem and by the time i got my new piston and it resleeved and new gaskets and all plus the labor it was around 1200. but thats nebraska pricing.