Will a 78 jug fit a 79?

[firebawlp]

After completely tearing down my motor (1979 250), I found the piston and "sleeve" unusable. I'm going to need both, so is ther any chance the 78 cylinder will fit the 79? THANKS, Adam

[sachsmx]

I can't answer with 100% confidence as my expertise is with the 1979 and later big bores:D, but I would bet that the '78 cylinder would fit your '79 lower end. I am thinking that the 250 engine didn't see any major changes until '80 or'81, maybe later. You may have to use the '79 head for clearance reasons near the pipe and/or frame rails. Good luck. I hope you get it going soon.

[firebawlp]

Thanks for the reply. Just to let anyone who read my last post know what happened, here is the story:

I was cleaning the airbox when I realized I was late for something, so I laid the bolts and washers in the bottom of the airbox, sat the seat back on it and left it parked. The next day I was all excited about riding it again, forgetting the bolts and washers. I was riding and noticed the seat wasn't tight, so I pulled down to the garage, hit the kill switch, put the bolts and washers back in, went to kick it and it was locked up. My own stupid mistake cost me big. It was 1 washer that went through in that final stroke after I hit the kill switch. Could've been worse though. Thanks again, Adam.

[tomale]

Adam, you said that the piston and the "sleeve" is unusable but what about the cylinder? If the sleeve is bad but the cylinder is not it can be resleeved. I belive that Al B. (see suppliers list on this site) it should give you a another way to handle the situation. I believe he does swap so that you will not have to wait too long to get it running again. But if you can get a usable cylinder somewhere else that might be cheaper.
Don't feel too bad, I am sure that you are not the only one who has done such a thing. I had a 69'montesa 360 that sucked a bolt from the air box and it managed to make its way all the way through and beat up the head and piston. I was trail riding with friends and I had to be towed about 8 miles back to camp and then I had to just sit there because we were not going home for another whole day.It was bad enoght that I had to replace the piston and have the head cleaned up and shaved down to make it work right again as I remember. I was really bumbed and It took me a long time to save up the money to pay for it. As I remember the piston cost me 45 dollars which was almost a whole weeks pay for me back then. by comparison I could buy a piston for the Suzuki 90 for 4 dollars. I about fell over backward because I could not understand why it was so expensive.
There is a reason that you were not made so that you can't kick yourself, it is rarly of any profit unless you manage to learn from it and move on. Hang in there. besides this is a great way to learn more about the bike you ride,this is alway a plus.  I have learned alot from my broken bikes, not very cheap but you usually will not do that again. That lesson for me I still remember and it has been over 30 years.

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.

[tomale]

Adam, I just had another thought, do a search for the information you are asking about. Seems to me several months ago someone was asking something along the same lines, you might find more information there. There is a search mode on this web site. it shows up in several places including the home page. See if this might be of some help.

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.