Look at this link:
http://fiche.ronayers.com/Index.cfm/Mod ... /OIL_PUMP_
Are you talking about part number 19?
It looks as if that bolt has two threaded ends with an area of no thread in the middle. Is that right? I haven;t physically laid hands on those bolts before; just the nuts.
Can you get the nut off of the bolt? If so, try threading the other end first and see if that has any effect. If you stripped the actual bolt hole then you are in a little more trouble and will have to have a machine shop repair that. I wouldn't trust myself to do it. SCrew that up and your bike will be unusable.
As far as the spark plug, did you make sure that it was gapped correctly?
Also, I occasionally get the "not hitting" from time to time. How many miles are on your bike? And, did you ever have your valves adjusted?