Well took the 250R out tuesday for a ride after a fresh topend rebuild. I had about 5 hours on it so far and the bad thing is, the cylinder is maxed out now with a 2mm overbore. The piston does not look to bad but has some minor scarring on it and the rings were stuck into the groove pretty good. The cylinder walls look somewhat ok with some melted aluminum on the walls. I am going to try some muratic acid on the aluminum and the run a hone up and down the cylinder to see if I can fix it up and then put some new rings on the piston and let it ride. My buddies uncle owns a Suzuki Shop and he told me that the shop that bored my cylinder may have not bored it out enough since it was the last bore and they may have caused my wiseco piston to seize up. I had .012 for the ring gap as suggested by the wiseco paper work, but I have heard that I should have went a little bigger. Anybody have any suggestions on where I can pick a jug that still has some life in it or any other suggestions? Thanks all

 

1. Did you check the piston to cylinder wall clearance?
2. Did you make sure the piston was in great shape before you installed it? I have bought a couple that had very small dings in the bottom skirt I had to buff out.
3. What did the plug look like after failure?
4. What oil are you running
5. what mix are you running it at
6. Did you overheat the engine? At 80 over some of the air cooled engines would cook themselves.


Without seeing the cylinder/piston; and just going off what you typed. I would say " DONT try to reuse you current setup. Once you leave aluminum on the cylinder, game over.
Look on e-bay for a jug. I have bought quite a few on there with good luck.

 

1. No I did not check piston to side wall clearance--I know that is my fault but was told piston was already fit to cylinder by the shop that did the bore.
2. Piston was brand new wiseco and everything looked good to me.
3. The plug looked perfect. The place we were riding was a shop and one of the mechanics asked the same question so I showed him and he said it looked great.
4&5. I run yamalube 2R(I believe) at 40:1 with 93 from Texaco or Exxon. I have been running this in all my pre mixers to include the LT-80 and have had no problem. If anything they all run a little rich which I would rather have a little rich than lean.
6. It could have overheated a little but I was running around at a pretty good speed, racing on a flat track, so I had plenty of air flow.

I am pretty sure that the piston was a little tight in the cylinder because I thought that when I put it in. I just want to get it running again so I can ride with the children some the rest of the summer. I really do not have the cash to resleave the jug right now so that is why I am looking for a used jug and I am going to try and make this one work for a little while longer. I can get the aluminum out with muratic acid and then I will be able to tell what the cylinder looks like. If I can take a thousandths out of the cylinder I might be fine as the clearance for a wiseco piston is 1 to 15 thousandths more than a standard piston. Thanks

 

hi
hone it out relieve the exhaust bridge .004
put it back together
klotz is better oil
you need more oil try 36:1
break it in slow

 

Thanks for the reply, where do I find Klotz oil at? I honed it out and I put a new set of rings in it. Plan on putting it back together tonight or tomorrow and see what she does, hopefully everything is okay for now.

 

sorry i dontknow if my reply went through cpu messed up

dennis kirk--1-800-328-9280
9.99 a quart---###--30-180
rocky mountain---1-800-336-5437
9.19 a quart --###--367-1044
this is really good oil ,burns clean,removes carbon buidup,and smells good too
even better with race fuel
klotz sells fuel too
also 4 stroke crank oil

 

Cool, I will order some today. Well I got it all back together last night. The cylinder dropped on so easy it kind of bothered me. Then got the head on and put the plug in to see what the compression was like and I could barely pump the kick starter by hand so I knew I had some compression. Finished it all up about 9pm and started it up. When it was running it sounded like someone was laughing in a high pitch voice. Then I realized I had an air leak on the left side between the jug and the case. In my haste of getting it back together I had forgot to scrape the gasket on the bottom of the jug, so now I will have to pull it all back apart and hope that my new gasket is not destroyed now. Oh, well at least it is running.

 

Well, pulled all the way back down again to check the bottom of the jug and like I thought I forgot to scrape off the gasket material. Cleaned it all back up and put it back together and all seems to be good for now. Now I just have to break in the rings again. I really hope this takes care of it for a while. Thanks for all the help!!!!

 

hey -
no problem have fun