piston in wrong?

[joe cool]

Just finally got my 3pg together . crank kit with piston and cyl new. When I try to start it it fires and tries to run about every third revolution. Same thing forward and reverse. Just not enough to keep going without the starter. I have lots of spark at the plug,I was very carefull to mark the timing plate and reinstall it correctly . Does this sound like a piston problem,? I am sure I even double checked it on installation. I did nothing to the carb I may pull the bowl off of it tomorrow . I was very sure to check the piston orientation. After all I am old.

[cart around]

The only way to know for sure is to remove the exhaust pipe, and look. Move the piston up, and down. If you see the piston holes through the exhaust, it's in backwards,

[cart around]

Did you put the rings bevel side up? Did you change the seals?

[joe cool]

Yes bevel side up and new seals and bearings. Thanks I will check the piston today

[joe cool]

finally was able to spend some time with this today ,Took the exhaust off and the piston was in correct , removed carb and cleaned . it just didn't seem possible ,it ran before ,just needed crank seals to help it start.Hated to go into ignition as I had spent a lot of time making sure I marked and replaced the module to keep the timing the same .As I was messing around with everything I bumped the two wire connector that leads to the module inside . Well to make this story short I had probably broke the last wire strand on one of the ends in that connector when I unhooked it when pulling the engine. I assume it would fire until it tried to start and the shaking would then break the connection.New ends solder on and it runs great. Glad I accidentally found it ,no telling how long I could have chased this problem.
Thanks to everyone who helped me .