Rebuilding. Stay stock or go 478cc?

[QuinnLT4]

Trying to decide if I should just stay at 439 or go to the big bore kit at 478

[Gray33]

478

[Off-Road Maniac]

depends on what your doing with it. How reliable do you want it to be etc....

[QuinnLT4]

I usually able to hit the dunes about once a month but other than that just buzzing around the back forty and occasional trails. So I like it to run smooth. Not a big fan of working on it more than riding it.

[greenblood01]

I'd go 449cc.. give it a bump but keep the reliability. There are many other things you can do to gain power besides displacement.

[ohsobad_chevy]

Originally posted by greenblood01
I'd go 449cc.. give it a bump but keep the reliability. There are many other things you can do to gain power besides displacement.

Very true. ;)

[downeyballz]

theres no reason a bigger bore would be less reliable. if i were you i would get the stock cylinder re-plated and go with a je big bore piston w/ 12:1 or 12.5:1 compression. you shold also do the oil squirter mod. that would make you quad much more reliable. i recomend the je piston because there better made and 3 ring, unlike some other 2 ring aftermarket pistons that dont last as long

[BrettOaktree]

if i were you id just find a cheap stock crank off an 06 or on and it will be a 449 and like someone else said reliable and a bump

[greenblood01]

Originally posted by downeyballz
theres no reason a bigger bore would be less reliable. if i were you i would get the stock cylinder re-plated and go with a je big bore piston w/ 12:1 or 12.5:1 compression. you shold also do the oil squirter mod. that would make you quad much more reliable. i recomend the je piston because there better made and 3 ring, unlike some other 2 ring aftermarket pistons that dont last as long

This is true, however I think it would be more beneficial to spend the money on cams, port work, intake, ignition..etc rather than shooting for more displacement.

[ohsobad_chevy]

Yup, porting and cams are great ways to get power. But remember, porting will make or break a motor. Good port work is priceless, but bad port work will kill the whole motor. Do your research. ;)

[Crazy lil punk]

I am also in a similar situation.

My Grandfather is an x-drag racer, and he always said, "there is no re-placement for displacement" haha

[downeyballz]

i wouldnt go with a bigger piston if your stock piston is in good shape. i dont think cams are necessary, just go with the cam mod.
i would never recoment re-building a perfectly good motor, just have fun blowing it up first, then re-build

[greenblood01]

Originally posted by downeyballz
i wouldnt go with a bigger piston if your stock piston is in good shape. i dont think cams are necessary, just go with the cam mod.
i would never recoment re-building a perfectly good motor, just have fun blowing it up first, then re-build

If you want more power I don't see any problem with purchasing a set of aftermarket cams. Blowing a motor up can damage things that would not be hurt otherwise such as cases, crank, head, cylinder, etc.. Thats what happened to the previous owner of my YFZ...

[ohsobad_chevy]

The stock cams (modded) in the YFZ are about as good as you can get. The gain from the woods cams or webbs are not worth the money, imo. ;)

[THORrider350]

dont do the cam mod, if you mess up its not worth $1200.00

[greenblood01]

Its not rocket science, just follow the instructions and double check anything. If you are too mechanically inclined take it to a shop and have it done. It was well worth it in my opinion.