top end help

[x_doug_x]

so i just put a fresh top end in about 2 weeks ago. after tuning tuning tuning and changing the reeds i had it perfect, but of course i wanted it faster. so i called kevin at herr and talked about getting my jugs ported sounded like a good deal, i pulled the cylinders off today to find that the right piston was all nicked up and so was the cylinder head. something got in there between piston and head and was beating around, it even nicked the side of the piston where the ports are in it. i shook the pipe to see if anything was in it, nothing. i checked the reeds all had the screws still in them. i stuck a magnet in the bottom end around crank and didn'tfind anything. i can't find whatever it was that caused this to happen, my clinders are not nicked they have up and down lines in them but i put my finger nail and can't feel any indentions. with about 45 minutes ride time, the cylinders still have hone marks as well from where they were just honed. i'm prob. going to get them honed again and put new pistons in. do you think the cylinder head will be ok? or am i going to lose compression, also i can't find waht caused this, do you think it will cause problems later if it fell in the bottom end? if it did the magnets not picking it up.

Edited July 15, 2009 by x_doug_x

[Rodneya]

Post some pics of the damage.

Are the wrist pin circlips in, and are you missing parts of the rings.

 

If you cant find what caused it, then I would split the cases and check down there. You may have dropped some crap down there during the rebuild.

 

What porting are you going with from Kevin?

 

[x_doug_x]

Post some pics of the damage.

Are the wrist pin circlips in, and are you missing parts of the rings.

 

If you cant find what caused it, then I would split the cases and check down there. You may have dropped some crap down there during the rebuild.

 

What porting are you going with from Kevin?

 

 

not sure exactly, just a full port job. for t5's told him i want it for trails and to run pretty good at drag strip when i bring it there. he didn't give me a specific port. the cylinders are fine "i think" no scraps, the piston just has nicks on the top

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[x_doug_x]

[KEVSWS6]

I have stock milled heads on the shelf. $50 no core. This will work well with your port job.

[x_doug_x]

I have stock milled heads on the shelf. $50 no core. This will work well with your port job.

 

i'll take them. let me get these sent off.

[Larry's Shee]

Just wondering what kind of pistons are those? Might just be photo but they look thick at the intake windows.

[x_doug_x]

Just wondering what kind of pistons are those? Might just be photo but they look thick at the intake windows.

 

 

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...RK%3AMEWNX%3AIT

[Larry's Shee]

By chance did you loose a small piece of the piston ring? Or have you determined the cause yet? Interested in what caused this. Thank you for info on pistons, might have been camera angle or just way I looked at pic. Please post if you determine cause.