Premix or Fix oil pump?

[Sanducksm]

Hi, I just bought a Callenger1800 with the carb M2, got it cheap because of engine problem which turns out to be 1 cyl melted 2 others at 110 psi a 3 at 125 psi. after engine strip I found the nylon oil pump gear suffered catastrophic failure my question is pre mix or do I fit a new oil drive gear?

 

[Dr Honda]

Since the engine is apart... I would just replace the gear. The new style gear is stronger. Besides... trying to properly mix 40 gallons of fuel is dang near impossible.

FYI... the reason the gear strips, is because the engine was overheated. When that happens, the bronze bushings swell, and get tight on the pump gear. You may want to consider replacing those also. The new ones have a little more clearance.

 

[Sanducksm]

Thanks very much for your info, its no1 cyl that melted all the others seem ok but the 3 on that bank had much lower compression? are there any other areas that I should check /improve when I am in the guts of it?