Need help with top end!

[JoSwinBlaster]

Ok so i have an 03 Blaster that is knocking because it was ran out of oil. But i believe its just the piston. I want to redo the top end but what i need help with is what if it scarred the cylinder? Do i just get a new Cylinder sleeve? And i dont know how to install those. Any help is appreciated, i wanna get her back to good shape soon!

 

[hudack]

if its scared just get it bored over to the next size why would u have to resleave it unless its outa life.

 

[tyler1blaster]

nope, bore to the next smallest size possible. is this the first time this has happned?

 

[scotj77]

yep. if it is a stock bore still. it should be a 66mm piston. buy yourself a 66.50mm piston .10 over stock bore and take it to a machine shop to have it bored to fit your new piston. you will need the piston before you have it bored out. If you are still running oil injection you should buy a block off kit at rockymountainatv.com (cheap) and mix your gas your self(32/1) then you won't ever have that problem again. kenoconorracing.com is a great guy and will bore your cylinder for cheap. he is thourough and knows what he is doing. Good luck!

 

[125pb]

.10 over would be a 66.25mm piston. but anyways a new bore, hone and get new gaskets too.

 

[scotj77]

my bad it's late. that is what I meant.

 

[sicivicdude]

If you do not have a bore gauge or at least a caliper, you don't need to order a new piston before taking it to the machine shop. It could have messed up more than .010" and you'll be out the price of that new piston because they might need to bore it more. If you don't know anything about engines the best bet is to use a service manual to remove the cylinder and piston (it's not hard) and take it to a machine shop. They can remove the aluminum from the bore, clean and measure your current bore size, order a new piston of your choosing, and bore your cylinder to match the new piston. When you go to pick up your cylinder it will be the proper size for the new piston with everything needed to reinstall it (usually they can order a piston kit which includes gaskets if you ask them to). It will cost more at the machine shop (they'll charge a little more for the parts than you can get them for yourself) but you're guaranteed to have the right parts when you get there and it will be a single stop to have everything ready to put your engine back together.

 

[JoSwinBlaster]

Alright thanks ill take it apart today and look at it. This is the first time this has happened so i just didnt know what to do. Ill post back on here if it was scarred or not!
But thanks!

 

[royalt67]

The one thing the manual won't tell you is that you dont have to completely remove the motor to take off the topend. Just leave it in place and remove the head and cylinder.

 

[JoSwinBlaster]

Alright guys i took the cylinder head off and removed the piston, it did a little knocking on the cylinder wall but not too bad. The Piston took the most damage though. I guess the rings got wore out.. But i should be taking it to the local shop and see what they say about getting it bored.