Help me fix mechanics mistakes

[GoodDerf]

So last year my spree broke and I didn't have time to fix it. Eventually my grandfather offered to have it fixed for me. After getting it back "fixed" it sounds like a small motorcycle and can't hit 25. I don't even know where to begin or what is going on. It has a taz bbk and uses premixed gas but otherwise it is stock. Any ideas where to start (besides cleaning the carb, I am doing that tomorrow) would be much appreciated.

[fastplastic]

air leaks

[Bear45-70]

Which BBK?

[GoodDerf]

The 44mm I believe, whichever one came out first. When I bought it about a year ago it was the only one out and taz had not made the gears yet.

[eliteguy50]

What happened the first time when "it broke"? If we know where they started looking or what was wrong, that would help in finding out what the shop did.

[GoodDerf]

The first time the piston clip broke and did a number on my piston and cylinder so I decided to get the 44mm bbk. While installing said kit I dropped one of the clips into the case and then it sat until it went to the mechanic. I told said mechanic that he needed to crack the engine case to get the clip and whatever else may be in there from when the original clip broke. Of course he didn't listen and "fixed" it the first time and ended up breaking the piston rings when he was testing it. Now I have it back "fixed" again and it behaves as I said in the OP.

[eliteguy50]

Is there any vibration with it running now?

[Bear45-70]

Is the stock air box on it still or an aftermarket unit?

What main jet is in the carb?

[fastplastic]

whats your plug look like?