Is that one of the older ones w/ the Iron piston? If so, and it has decent compression, it might be just as FBD sez...add some castor to your fuel and try (if you don't have already ) a #8 plug? Those older FP's and earlier MAX .20's etc. like a lot of oil, specifically castor...20% or even more.

I found an empty qt. can of Fox "Superfuel" and it's got the list of ingredients right on the front of the can:
29% (!) Castor Oil
64% Methanol
5% Nitro
1% Detergent
1% Ignitors

Thought that was interesting...