Stainless Plus Aluminum + salt water = Stuck bolts.

[Redbarron%%]

I am replacing the engine and the fuel tank in my Hobie Jet Skiff and this is a major project.
I have built up a spare motor to replace one that ingested water due to an improper gasket at the base. The old motor runs, but is making a worrisone noise at the top of the engine.
BUT that is not what I am posting about. To get the new fuel tank in from the rear the post that holds the throttle shaft for the Jet is too high. No problem I thought, just pull the top of the pump, but NOoooo the studs at the rear of the engine are stuck probably by the corrosion products between the sides of the hole and the studs.
I have tried heat and WD40 over a few days and continue to do so.
Anyone have any suggestions?I have the front bolts where I can wiggle the plate, but the thing is solid at the rear and judicial prying only make me worry about cracking the fiberglass mount.

 

[alldodge]

Would suggest a penetrating fluid like PB blaster, Kroil or other. WD is a water displacement fluid

Need also some heat, but this could be an issue due to tank and fiberglass. Can get a heat blanket like those used by plumbers or welders to keep heat from areas

 

[Redbarron%%]

The fuel tank is out (in pieces and also a victim of salt water)
I can heat (an have) with a propane torch I need to get a little hotter, perhaps.
I hate to cut out part of the floor drains, but that may be the answer if I can't get the top of the jet pump off to get the throttle cable mount out of the way.
Always something with a boat! Double that with a boat that is operated on salt water!!

 

[Scott Danforth]

if you dont have Kroil or PB blaster, 1/2 acetone, 1/2 ATF works just like kroil.