I got this 1981 ds125 not running really at all. i put some time into it and we have it running now. the problem i am having though is it will only push start, and it revs in neutral fine but soon as you put a load it dies and bogs out. things i have done. brand new carb checked the reeds mixed my own oil 32:1 blocked the oil pump checked the compression it has 120psi exhaust is clear new spark plug the only thing is the piston has some scoring but it still has great compression im lost at the moment.... help?