Do I need to bore or hone? 760

[JonnyB]

ok took my 760 apart and noticed the scuffing on the sleaves and on the pistons. I know I will need new pistons/rings but do I need to bore or hone? also ski was runing 150psi in both before taking apart and thats with 38cc domes

MAG http://s21.photobucket.com/pbwidget.swf?pbwurl=http://w21.photobucket.com/albums/b266/MDCDCCFan/Ski/1171593817.pbw&os=1

PTO http://s21.photobucket.com/pbwidget.swf?pbwurl=http://w21.photobucket.com/albums/b266/MDCDCCFan/Ski/1171593901.pbw&os=1

 

[MADMAT]

Wow those pics move SSSLLLLOOOOWWWWW!!!!

I have seen worse but while its apart.................

And it is winter

 

[MADMAT]

Oh nevermind yall don't know about this winter stuff.

But I wouold say yea. New pistons, fresh bore.

 

[JonnyB]

I had a feeling it would need it, thanks!

 

[steve802cc]

If your already buying pistons I'd bore it next over. Boring will make sure the cylinders are straight and not oval from years of wear. Honing alone will not straighten out the bore.
Steve

 

[#ZERO]

Yep ... to bore each cylinder hole usually cost between 50 to 70 bucks.

Just be sure to give the machine shop the new pistons so they can measure them for the correct bore size and clearance specifications

 

[ANT]

bore it. maybe your a little lean too.

 

[Prem1x]

I agree with all the above. Besides, there's no way to measure clearances or whether the cylinder is oblong through the pictures. However, if you're unsure that you want to go to the next size up, have someone put a micrometer on it for you.

 

[JonnyB]

Thanks guys I had a feeling I was going to need to bore it. So I will be going the next size up 85mm (already has a bore on it)

 

[SUPERTUNE]

JoonyB, Do you know what the last bore job piston to wall clearances were set to? Looks like it was too tight on the clearances, (from looking at the burn pattern on the piston top) were you running dual cooling? If so you might be able to just hone the cylinders for increased clearences, But the pistons don't look like they will survive, Mic'ing the good one and maybe a light pressure GLASS beading might make it usable, the seized one is most likely dead!
PM me if have any questions. Bore, hone and chamfer runs $60 per bore.

 

[JonnyB]

JoonyB, Do you know what the last bore job piston to wall clearances were set to? Looks like it was too tight on the clearances, (from looking at the burn pattern on the piston top) were you running dual cooling? If so you might be able to just hone the cylinders for increased clearences, But the pistons don't look like they will survive, Mic'ing the good one and maybe a light pressure GLASS beading might make it usable, the seized one is most likely dead!
PM me if have any questions. Bore, hone and chamfer runs $60 per bore.

I bought the ski used I can PM the old owner see if he knows. I am running dual cooling. I have no problem spending the money on pistons and a bore I just wanted to post this up to get a second option just incase it didn't need a bore. I much rather do it right while its apart so it will run good in the summer. I am on crunch time to have it done before Lonestar Freeride

 

[kskip]

Get your next oversize Pistons and Bore it...
kskip