Are these interchangable? I think my OMP is going south and can get ahold of a SE OMP fairly cheap. Also, Is there a way to adjust the 86-88 OMP like the SE pump? I didn't see a little adjustment screw and lock nut like the SE pump had. Thanks for the help.

 

i thougt the only difference was the size rod.

 

It's easier to pick up an S4 mop, if that's what you need. As Adam stated, the 1st gen mop rod is a smaller diameter than the 2nd gen one. The mops are also rebuildable.

 

Ok, I'll look into a rebuild kit the. When I look at my pump though it doesn't look like there is a pump adjustment screw though. Maybe i'm missing it because the lower radiator hose is in the way, But from what I can see is just the pump lever and lever stop. Are you suppose to shim the omp rod the get desired output because even when the rod is disconnected from the carb the pump lever doesn't drop any further which tells me it's closed at idle if everything else stated is true.