should i get my topend bored out?

[jtomasi1]

I have a top end that i brought to yamaha and the guy said it would be ok just to do a honeing, but it still wouldnt be perfect. he said that it would be take 2-3 weeks to bore it out. what should i do. i want it to be perfect and its only 40$ more to bore it out. It is worth it? i dunno if i cant wait that long. is there a faster solution? i would just get it bored to .02 more. also , if i say i want it .02 over and buy a piston from another place (cheaper than yamaha) is it going to fit perfectly or is there a chance its going to be differnt.

 

[Roccdeezy]

20 over is 20 over. When you buy a piston just make sure it is 20 over. doesn't matter where you buy it. Also if they said you could get by with a hone then go that way and use the $40 for porting mods. Everybody thinks a overbore means more power. Well, It isn't enough power to even notice. More POWER = more air and more gas. So with porting you will be able to get more air and gas into the cylinder and get more power.

 

[jtomasi1]

how would i get porting mods. would it have to be "cut" out by a dealer or something?

 

[jtomasi1]

does honing really make that much of a difference?

 

[Roccdeezy]

Every cylinder needs a good hone. Except aluminum and nikelsil. The reason for honing is to have a place for oil to hide in the cylinder when the piston moves up and down. This is what keeps the rings oiled and it also keeps the rings from wearing.

 

[Roccdeezy]

All porting will need to be done by a small engine's machine shop, atv dealer, or a race shop. Lots of people do it. The best thing if you want mods would be to send the jug to CT racing or trenga racing. But I'm sure there is someone local to you.

 

[jtomasi1]

but wouldnt that hurt the compression. or are they such small etchings it wont make a difference?

 

[Roccdeezy]

No because they will hold oil and oil on the cylinder will actually give you better compression. It will keep the rings from leaking and wearing

 

[Roccdeezy]

Haven't you ever heard of people putting oil in cylinders on cars when the compression is low to figure out wheather or not it is a valve or ring giving the engine low compression. If it is a bad ring on a car the compression will come up when doing this test. If it is a valve giving the engine bad compression the reading will stay the same. Make sense. The oil will actually seal the ring better.