Piston....

[fatboytank320]

I recently got a 1995 blaster, needs alot of work, I mean alot lol. Well first off it has no compression at all, the guy said he just rebuilt it .020...So I got it started after choking the hell out of it and pumpin the throttle and needless to say it was a turd. While it was running it was making a hell of a noise, sounded like the piston slapping around. So I tore into it today and was checking it out, well it is .020 over but you can actually move the piston side to side with ur fingers while its in the cylinder. With new rings would that eliminate the slapping? Or did this idiot put the wrong size piston & rings in it? Anyhelp is much appreciated, thanks.

 

[blasterfreek30]

more than likely it was not bored over and thats the stock piston in it......u prolly need a new bore job with that much play in it

 

[yb200]

more than likely it was not bored over and thats the stock piston in it......u prolly need a new bore job with that much play in it

i think he said it was bored 20 over.......what are the numbers on the piston

 

[J4M1E333]

Yeah sounds like an over bore but stock piston, get the micrometer out and measure that shiz man, wouldn't run it either because if it's been bored and still a stock piston your likely to trash the cylinder, with the stock piston slapping all over the place.

 

[blasterfreek30]

i think he said it was bored 20 over.......what are the numbers on the piston

yea but would u beleive i guy that said " it was just bored 20 over".....ahh slim chance

 

[fatboytank320]

It does have a Wiseco Piston in it...Last 4 digits on the number read 66.50 I ran it for about 3 minutes and it started slapping around, guy told me he thought it might need crank bearings but I think he just put the wrong damn piston in it lol....Cylinder looks like its in great shape though...Im gonna go get a micrometer tommorrow anyways, I shoulda bought one a long time ago. Someone might have to help me on that cuz if I buy one Im gonna be lost on what I'm suppose to do lol.

 

[J4M1E333]

anymore on this fatboytank?? you got her running yet?

 

[4StrokeHater]

That means it's a 66.5mm piston.. From what I understand .020" over is .5mm so if he says it's bored .020" over then that is the correct piston size for that cylinder.. Take the rings off and take a look at them. I'd also take the cylinder itself to a boring shop and have them inspect it as a micrometer will not suffice. They have special tools to measure such things as cylinder walls, and they can see better than you if it's time for a fresh bore or if a hone and new rings will do fine.