Engine did act up once before major when I pulled on a gravel road slow with a steep grade.

I was think tank vent. Right now I have a plastic tank that self drained the other day (about 10L due to parts guy selling me a tank plug that was not petro rated (ahhhhh). Tank will be swapped out in 3 months when I get it back to the shop, tank should be free of bacteria since it is all new fuel!!

I will check the tank vent or leave the cap loose for a while.

The lift pump I have is outside that tank and pulls through two filters (I was thinking of eliminating it from the system since it is not required)

Thanks for the ideas!!!! Cheers David