Exhaust cover bolt 1998 75 Force

[TwoFish]

I?m trying to remove the exhaust bolts in my 1998 75 force. Some of them have come out easily but others seem extremely corroded. The motor has been run in salt water.

I have already snapped one bolt off level with the block.

I have read other posts that say they have had to work at the bolts for days to loosen then. I not sure what ?work at them? involves.

I have sprayed Inox on them hoping it would work it?s way in. I have access to an oxy/propane torch. I tried gently heating the bolts. Have also tapped the heads of the bolts to try to vibrate the corrosion loose.

Not sure where to go from here. I can get some bolts to move but I now realise that it is only the bolt itself twisting. I?m reluctant to try and turn the bolts back and forth as I don?t want to fatigue them.

I?m hoping to remove the cover without having to remove the power head. The lower cowl does not come off with out removing the power head.

Any suggestions would be appreciated.

 

[jerryjerry05]

Re: Exhaust cover bolt 1998 75 Force

I spray PB Blaster(don't know what Inox is)
Let it soak.
Then I tap the head with a small hammer,spray again then heat with a small propane torch.
Then tap,spray,heat then repeat.
Do this and as you do try to loosen a TINY bit.
Then repeat tap,spray,heat again and again.
It might take an hour a bolt.
I worked about 2 hours to loosen the 4 screws on the thermo housing.

The tapping loosens the corrosion around the threads.
So does the heat and PB Blaster.

Takes LOTS of patients!!!

You might be able to loosen the bottom cowl enough to work on the bottom bolts??

 

[TwoFish]

Re: Exhaust cover bolt 1998 75 Force

Thanks for the advice. I have snapped 2 already. 10 are loose and another 8 still frozen. I was not sure how much heat to use. Unfortunately as far as I can see the cowl is held in place by the powerhead on this motor. I will try again Friday.