Pics of fryed piston. I think it was to lean?.(picture of top of piston)

[bushwacker51]

Guys,
Thanks for all your help. I swear I had the trike hot before I cracked the throttle open all the way. But the guy that ported the cylinder had some machinest bore the cylinder for me and I dont know who he was so......... I dont think I can just hone it there are some deep scraring marks on the cylinder walls. If it was my torro lawn mower engine I would hone it slap new rings and piston in it and go on but dont want take a chance with my baby. Once again thanks for all your help makes me feel a little better I did not lean it out and fry a piston. Glenn O.

[oddball3]

If you got a good ring slide it down in the bore and measure your ring gap, if your below specs you might just be able to hone out the marks and just use a new piston and rings.

[DIGGER DOG]

were the ports chamfered?? when you got yhe cylinder back did the ports have sharp edges or were they rounded off ?? if the ports were sharp when you got the cylinder back the machine shop owes you a bore job because your piston rings caught on the ports and bridges of the cylinder, also definately check the ring end gap to see if they are to spec. you may have had improper ring to cyl. or piston to cyl. clearance. or it could be cold seize but i would be willing to bet the machine shop screwed up and didnt chamfer the ports .
i am by far not an expert or a professional but I am attending motorcycle mechanics institute (MMI) Im in machine shop now where we bore,rigid hone,and flex hone the cross hatch in the cylinders as well as cut valve seats,press valve guides,reface valves,and true crank shafts etc.. etc...... like i said im not an expert just my 2 cents.

[crackshot]

You people and your 2 strokes. I have had countless 2 strokes through the year.
After a rebuild, RUN YOUR PREMIX RICH during break in and I mean where you see smoke coming out pipe. Cheaper to replace fouled plugs than to tear down again and again.
Ya wanna know another secret? Don't baby them during break in. You want it to go fast? Run it hard during break in for 15 minutes at a time then let cool down 30 minutes.

[Blown 331]

Ya wanna know another secret? Don't baby them during break in. You want it to go fast? Run it hard during break in for 15 minutes at a time then let cool down 30 minutes.

This should probably be split into another thread, acutally I'm sure it has been discussed in the passed. I highly disagree and I don't know how anyone can think that is a good idea. An engine is an engine and I have lots of automotive credentials. Let take an 2003 Cobra for example. You can have 2 identical cars. Break one in like you say, break one in easy. The one that was broken in easily will have an easy 20 more rear wheel horse power on the dyno, seen this quite a few times and other examples just like it.

[denn]

ok, wiesco pistons expand a bunch more than a stock cast piston. This is due to being forged aluminum. This is no different than any other aluminum item. You would not normally run aluminum connecting rods in your 350 chevy engine if you were using it on the street all the time would you. No, It wouldn't be practical. The aluminum rods expand upwards more than steel so you would have to leave more deck clearance between the top of the block and the head. You could do it no problem but you would have to take your time and make sure all clearances are correct. Meaning really blueprint your engine. Steel would just be eaiser and less precise. Well when you get a wiesco piston the best way to install it is to have the piston in hand and take it and your cylinder to the boring place. They should measure up the piston and then bore your cylinder to the piston leaving the extra clearance for expansion. Of course, the cold seizure thing is still true and will happen but if the cylinder is bored to the piston it will be running it is less likley. I know that when I change pistons if it is a new piston I will start it up and take it easy letting the bike get hot and cold a few times after that I beat the hell out of it. Letting it get hot and cold makes the piston expand and contract a few times. So eventually it wont expand and contract as much. After that you should be able to get on the bike start it up and go. I don't let it warm up to much after that. How many people here have blown up a stock piston on a stock bike. I'm sure it isn't to many. Most of the problems is when you change pistons it is machinest error or jetting problems that are caused by another aftermarket part. Anyway, hope this helps.