No bottem end?? HELP!

[StupidHurts]

I have an 86 250r that i got about a year ago. when i bought the quad the engine had been torn apart because the counter balencer bearing set free and destroyed the left side case. i bought an engine off ebay for $600. The engine was bone stock when i got it. i added a pro design cool head with v force rad system. it also has a k&n air filter with fmf fatty pipe. when i first started riding it the plug kept fouling until i put a hotter plug in. i noticed that it had no bottem end and the only why to get power was to rev the crap out of it. Its hard to ride like this because by the time i rev it up to a point were i have power, i have to shift. i have owned 2 strokes all my life and i know that theres something wrong. i tryed adjusting the needle, the floats, the reeds, air mixture screw and i checked all the ignition parts jsut to make sure. i cant think of anything else but to change the jets a size down. i think im getting way to much gas and the engine cant take it. i pipe leaks alot around the head and were it connects to the silencer. I just want to know if im missing anything? i thought i came close today by cutting some air to the carb and adjusting the air mixture screw again. it seemed alittle better but i dont know what else to do so if any body could help that would be great. Also the air box had an outerware not a lid.
thanks

[C-LEIGH RACING]

If you dont have a compression gauge, you need to get one & do a compression check.
There are alot of things you can do to the 250R engine to make it have HP, but with any of those builds the main thing is compression.
If compression is low, then you cant flow & burn as much fuel because you dont have the compression to fire it.
That in turn creates another problem, if you cant burn it, then you cant flow a large amount through the engine to keep everything lubed & cool.
High compression, not too high, say around 200-220, you can flow some fuel through the engine making it last longer & the compression can help burn it.

High compression helps make bottom end power, makes the engine pull harder in the lower rpms.

But in short, compression is the key on any 2 stroke, the proper amount that is.

On a top end engine or drag engine, compressions not that big of a thing, yes you need it the proper amount as well, but best to go by the old rule, high compression & high rpm fight each other.

Neil

[StupidHurts]

Ok I checked the compression with a reguler compression tester (not digital) and 3 out of 3 times i only got 150psi...i believe i have found my problem and i have a spare top end that just needs a cleaning..i will port and polish it while im at it. thank you so much for your help its saved alot of time and money.