Ruined my engine...

[WheelieMan4]

Well i need to get a new piston for my quad...to much dirt in my engine i guess...but my question is, what seals do i need to purchase for this? i already got the gaskets...and should i also replace the bearings? thanks alot...by the way im going aftermarket, JE 88mm 11:1 piston and HCS2...thanks


one other quick ?....i just ordered my parking brake block off and new clutch perch and lever...it doesnt have a boot, is that bad?? what can i do about it?? thanks

[premiumtommy]

seals???

dont need any

just a head gasket and a base gasket

i am not sure you're gonna want to run an 11:1 piston w/o a performance camshaft

since you're gonna be taking the topend apart, you might as well spend another $100 on a cam and throw it in

the new clutch shouldn't need a boot

it will look like a regular lever like off a bmx bike

good luck

[WheelieMan4]

i already bought a hotcam stage 2, havent got the piston yet...so what would you recomend on the compression? 10:8:1??

[RiderTRX400ex]

he didnt think you had a cam.. 11:1 will be fine with the stg 2 HC

[lghickman21]

Someone will correct me if I am wrong but I believe you may have to start using race gas if you use the 11:1 piston. Might be something to consider. You shouldn't need any seals unless the dirt ruined one of you valve seals. You will definately enjoy the 426 over stock!

[wheeltrax]

you should be fine running 93 with 11:1. Mine runs fine on it.

[WheelieMan4]

yea thats what i thought, i was pretty sure that 11:1 is the highest you can go on 93...well my dealership told me i needed to get new seals?? so i dunno what to think

[440exnacsracer]

if the bike has enough hours or enough dirt has gotten in to wear out the factory top end, its never a bad idea to go ahead and change your valve seals. they are very inexpensive, and not too bad to put in.

[bwamos]

Originally posted by 440exnacsracer
if the bike has enough hours or enough dirt has gotten in to wear out the factory top end, its never a bad idea to go ahead and change your valve seals. they are very inexpensive, and not too bad to put in.

Especially since you'll already have her torn apart. ;)

[400exrules]

how high compression can you go with the stock rod and studs, etc.

[440exnacsracer]

Originally posted by 400exrules
how high compression can you go with the stock rod and studs, etc.

i cant remember what the 88mm puts your 400 at, if its the 426 kit with the stock sleeve, you would be safe up to about 12:1 compression. if thats the 440 kit, i would run the lowest compression you can get, perhaps 10.5:1. the stock rod on the 400s is nearly bulletproof, but with larger bores you will naturally get higher compression, then with a higher compression piston, you run into the studs actually stretching resulting in blown head gaskets. if you are serious about it, i would order some heavy duty cylinder studs regardless. maybe someone could lead you in the direction of these, im not sure where to find them

[honda460ex]

GT Thunder sells the heavy duty head studs. If I remember correctly, only like $70 or so for them. I've not blown a gasket or had any problem out of my 460ex, 13 to 1 compression with the heavy duty head studs. Been together over a year now and never turned a wrench on it yet.

[440exnacsracer]

Originally posted by honda460ex
GT Thunder sells the heavy duty head studs. If I remember correctly, only like $70 or so for them. I've not blown a gasket or had any problem out of my 460ex, 13 to 1 compression with the heavy duty head studs. Been together over a year now and never turned a wrench on it yet.


wow, thats not doing bad...who says you cant have a big bore and low maintanence:D

[krt400ex]

[QUOTE]Originally posted by premiumtommy
[B]seals???

i am not sure you're gonna want to run an 11:1 piston w/o a performance camshaft

since you're gonna be taking the topend apart, you might as well spend another $100 on a cam and throw it in





uh, he's got a stage 2 hotcam. that is a performance cam.:huh

[400exstud]

Dude, chill. Not everyone on here knows that HCS2 stands for Hotcam. Hell..... I didn't even know:p

[krt400ex]

Originally posted by 400exstud
Dude, chill. Not everyone on here knows that HCS2 stands for Hotcam. Hell..... I didn't even know:p

sorry, didn't mean to offend anyone.