brought a spare repair lexmoto torando 125 completely rebuilt the engine it had in it at the time as the guy had cooked the pison to point it melted onto the pin and the pin melted onto the crank shaft so i brought a new piston crank shaft barrel and head and gaskests and carb and cdi box put that all together it started nicely but wouldnt go top speed lucky to go over 40 mph 2nd problem is it would miss fire excample driving down the street and all of a sudden sould just drop power i would then decrease power and then gentley put the power back on to get power but even then 50 cc would go faster ...

so i brought a yibon 125 spare and repair same engine with oil leak replaced the crack seal as someone has used a rage inside the engine to soak up the oil total cowboy job brought crack seal no more oil leak dropped that engine onto the lexmoto same problem so on to engine number 3 engine number 3 had no crab used one the other carbs fired it up on the table rev like a dream dropped that into the big same problem

the bike has a Immobilise eletric start and a keyfobe start and one them looks like cheap alarm off ebay on it any help ideas apperiated