gouged kx250 cylinder ?

[woodsrider73]

i am rebuilding the top end on my 03 kx250 with about 40-50hrs on it. i was replacing the orings on my pipe cause it was leaking slighly and upon inspecting the cylinder i saw what looked like a crack in the cylinder on the intake side. i decided to go ahead and pull it apart. when i did what i found was this gouge in the cylinder, no crack.


i also found a small impression and the visible scratch on the piston. the rod bearing and bottom end is fine so i am figuring it must have sucked in a small piece of debris somehow.


the rest of it looks ok.




i am trying to decide weather or not to go ahead and put a new piston and rings in and check it again in 20hrs or so or should i have it re-plated? the other option i'm considering if repair is in order is eric gorr's 265kit with the low/midrange porting.

so i guess the question is would you run this cylinder with the small gouge in it?
or is it a bad idea?
 

[hughes]

How deep is the gouge? That cylinder looks pretty good. Looks like you could run a ball hone through it and be good to go. The piston wear looks good to. The last picture of the cylinder you can see some oil glazing. Ball hone will clean that up for you.

[sandman540]

with the headpipe being loose dirt and crud will get sucked back in the cylinder. I would just hone it and replace the piston and rings if it checks good with a dial bore guage. as you can see with all of the dark staining in the cylinder you can see that the cylinder is not very round causing ring sealing issues. if it checks ok then re ring, piston after the cyl has been deglazed....my .02...since i own a engine shop thats what i would do....Sandman

[woodsrider73]

thanks for the advice guys. the gouge isn't that deep. i'd say.001"-.002" maybe. the pipe wasn't loose enough to suck in any dirt, is was just spooging a little for the very 1st time with the new fmf pipe. the stocker never leaked. i did notice how much easier it slid into the cylinder than the stock pipe. i was just going to put the larger orings on it and put it back on when i saw this.

i'm deffinately gonna go ahead and hone it and put new piston/rings in. as well as making sure it is broken in properly.

[woodsrider73]

well i got the cylinder honed by a local shop today for 10$.
you can see in the 1st pic the gouge is still slightly visible but they said it should be ok.
i guess i'll just have to keep an eye on it.

[hughes]

Looks good. Shouldn't be an issue. have fun.

[woodsrider73]

just wanted to update this. rebuild is finished with wiseco forged piston and cometic gaskets, new vent/drain hoses on the carb, fresh plug and air filter. i just did my 1st heat cycle to break it in. it started 1st kick, i'm happy considering this is my 1st 2 stroke rebuild.

[Friar-Tuck]

 Glad to hear things worked out.
    Piston ,Rings ,Gaskets etc. ... $150.00
     Grin from Ear to Ear and Bugs in Yer Teeth .....Priceless 
Tuck \o/