More problems with Huntmaster chopper

[Davidmeachen]

Hi Guys, well once again the gremlins have struck so once again in need of some advice. I went for a short ride this morning and noticed the right hand cylinder was smoking a bit. I thought it would soon clear so rode about 1/4 mile and still smoking. Then right hand cylinder stopped firing about hundred yards from home. Completed the journey on one cylinder. Took out the right plug and well oiled so quick clean and replaced and bike started first kick with loads of smoke. Then I noticed no oil going up the pipe to the top of the engine so switched off. Checked oil tank: very low! It was full yesterday so where had the oil gone. Undid the sump and all the missing oil flowed out. I refilled the tank and started the bike again. oil poured out of the sump. Thinking there must be a problem with the pump I took the timing cover off, removed the oil pump and stripped it down; everything appears to be in order. Replaced the pump ensuring the gasket didn't block any holes and connected the oil pipes. Started the bike again, still no feed to the top of the engine and oil pouring out from somewhere behind the pump. Have any of you guys got any Idea as to what's gone wrong now?
This seems typical of my luck lately as the bike is now up for sale but obviously is, at the moment, a non-runner. Would appreciate any advice
Thanks guys
Dave