Hey all, Sometime in the future before my zilla gets a new topend end, I figured I might want to take care of some common problems. Since once I get it going and I may want to start increasing performance.

12mm head studs? Mine still has the 10mm, is it worth getting? it still has the stock head also

I have to get the next size up piston from a 1.5mm (.060?) over bore, should I get it resleeved also?

Still has the messy port castings. Could anyone give me a good porters name? I was looking to keep the stock powerband just increase it some, so its not a weak spot in the in the motor, since all I want it to be is a potent trail machine. Polishing sounds good also.

Sport port templates? There are some on ebay that look interesting. They send you the templates and instructions to do it, so you could take it to a reputable form there I take it? anybody know about these?

thanks!

 

Broke

The 12mm head studs are a good idea, but not absolutely required. I don't have them with my stock head and have not had a problem yet. I do however have an o ring set up-rather than using a head gasket I use two orings. Pennzilla uses a copper head gasket and has had success with that. I suggest one or the other.

I don't know if you should get it resleeved. I have no experience with a +.060 bore.

I can suggest only someone not to go to for your port job. Jerry Hall ported my first jug and it was a grenade. I did leak down tests, different piston manufacturers, you name it and I tried it. I ended up with a new (well, used) cylinder and the problems went away. Perhaps Hall had an off day I don't know. I shouldn't dis the guy but it was not a good job after all.

Port templates are also something I have no experience with. Too many people comment on these forums about stuff they don't know about.

Good luck getting your 500 back together. What a great quad the 500 is.

 

I just had mine bored to .60 over (1.5mm). Every 0.2" is 0.5mm
Wiseco makes pistons up to 1.40 over!!! You are not even close to re-sleeving. I also had to have my main crank bearing bore in each case half repaired. If you take everything apart and your main bearing is loose inside it's bore,then you'll need to have this mod done to make it right. CT racing did mine and they machine it out to accept a steel sleeve that will restore that nice, tight fit. Good as new! Cost $220-250 bucks, though. good luck
Addict

 

You shouldnt need to change the studs if you have an 88 model engine. They started doing this with the 87 model due to head gasket problems. A word of advice to the guy above me. .60 is actually 600 thousandths of an inch. The proper way to wright it is .060 which would be 60 thousandths of an inch. He is right that the cylinder can be bored to .140 which is one hundred and forty thousandths. Keep on top of any problems that arise and you will be pleased with the quad.

 

Wow! .140...damn! how many cc's would be gained? Just wondering, Thanks everybodys for sharing.