I was riding over the weekend and all went well until it started loosing power. (Allmost seemed like the plug was getting fouled since I was riding slow)

I replaced the plug, which looked bad but not terrible and all I get is an occassional backfire.

When trying to start, it doesn't sound like it normally does. I know that is vague.....

I am at a complete loss on what the heck is going on...please..anyone got some suggestions.......

 

First thing is check compression. Hopefully may not be,but sounds like the usual loss of compression on a 2-stroke when a piston starts to seize: bogs down and looses power while riding, popping back when trying to restart,etc. Plus pull up on recoil and see if engine is easy to turn over or still has a good amount of resistance on the the pull rope. Keep us updated. OPT

 

Tried the rope pull and it feels the same.

What is the worst case senario I am looking at?

 

Compression test is the best way to tell if its an internal problem or not. If compression is only about 100 psi or less , but still tries to run and makes unusual noise(metallic,grinding sound),could be top end problem. OPT

 

When it tries to start, it sounds "hollow".

So it might need a top end rebuild?

 

Just have the compression checked first and go from there! Brand new out of the crate or a well done rebuilt top end should have between 130-140 psi. If below 100 psi,then I would say yes the top end would need to be checked out! OPT