Engine Trouble Low power after remounting engine to new bicycle

[Deleted member 27811]

Can you guys point me in the right direction at least?! Do I need need new piston head an rings? Or should I give up and buy buy new engine?

Do the second engine and keep the bad one for your learning curve or just a new cyl.& piston. If you removed the cyl. and moved the ring set into a different position, it could have caused your issue, due to fact they seat themselves during break-in and don't like it when you look @ them cross-eyed. is it possible you left some particles in the cyl.?

 

[Frankenstein]

Let me give it some deep thought......
View attachment 78539

At least the camera man didn't get killed by the train.

 

[Deleted member 27811]

At least the camera man didn't get killed by the train.

I'm fine, thanks Frank.

 

[micromaster22]

Do the second engine and keep the bad one for your learning curve or just a new cyl.& piston. If you removed the cyl. and moved the ring set into a different position, it could have caused your issue, due to fact they seat themselves during break-in and don't like it when you look @ them cross-eyed. is it possible you left some particles in the cyl.?

So if I purchase a new cylinder and piston with the Rings need to be adjusted or do I throw it on there and let the Rings seat themselves

 

[Deleted member 27811]

So if I purchase a new cylinder and piston with the Rings need to be adjusted or do I throw it on there and let the Rings seat themselves

reading: Two Stroke Performance Tuning Two Stroke Tuners Handbook
Two Stroke Premix Oil Ratios by Gordon Jennings

 

[crassius]

I saw nothing horribly wrong in the vid - also doubt that the head gasket was bad, and certain that a mechanic would have lifted it off intact

those rings do not turn easily when in the cylinder since the grooves have location pins to hold them in the right place - you may have gotten that wrong when you put it together

I advise getting a new motor, as it seems unlikely that you would be successful in rebuilding a top end, AND the problem with the old motor may even be elsewhere than the top end.

 

[micromaster22]

I saw nothing horribly wrong in the vid - also doubt that the head gasket was bad, and certain that a mechanic would have lifted it off intact

those rings do not turn easily when in the cylinder since the grooves have location pins to hold them in the right place - you may have gotten that wrong when you put it together

I advise getting a new motor, as it seems unlikely that you would be successful in rebuilding a top end, AND the problem with the old motor may even be elsewhere than the top end.

Thanks crassius. The rings moved around around the piston. I will go ahead and get a new motor and fix this one

 

[crassius]

good idea - those rings should have been placed so they would grab onto the locating pin when installed into cylinder

 

[micromaster22]

good idea - those rings should have been placed so they would grab onto the locating pin when installed into cylinder

So I could potentially fix this engine if I move the rings back in the right or is that too difficult

 

[crassius]

depends on whether they broke because of being misaligned, or maybe dug a long gouge into cylinder wall

ride the new motor while reading and trying to fix the old one - it may take quite a while to get good at this