89 Mariner 100hp

[utfyrfytr]

I have a water leak on the lower port side cyl block cover so I need to pull the cover and replace the gasket. I am sure most of the bolts will be rusty and seized. What do you recommend for getting the bolts out without breaking them? I have been thinking about heating them with a heat gun, any other ideas? I'm also sure I will twist a couple off so does anyone know the size and hardness so I can find replacement bolts? Thanks for any ideas.

 

[Texasmark]

I just quoted this suggestion and will restate for you. I think it was "racerone" who grinds the heads off , removes the cover, soaks the threads overnight in a quality penetrating oil and removes them with vise grips. That is a great idea as the penetrating oil can get right at the threads and work better.

I normally soak over night and then use an impact approach on the bolt hex heads rather than a brute force twisting motion to get mine out without breaking things off.

I like his idea better because you can get right to the threads and I feel that grasping the shank rather than the head eliminates the shank to head interface area which is where mine broke when that occured.

I think you are talking about the exhaust water jacket cover. There are two gaskets, the outside cover to the water to exhaust separation plate, and that plate to the block.

 

[utfyrfytr]

Sounds like a great idea. It is the gasket on the rear of the motor where the spark plugs are that is leaking. According to the parts diagram it is the cylinder block cover and there is only one gasket. Do you have any info on what bolts I should use?Thanks again for your help.

 

[johnnyga]

use b p blaster let it soak for at least 2 hr then heat gun around the bolts.

 

[Texasmark]

use b p blaster let it soak for at least 2 hr then heat gun around the bolts.

For a readily available great working oil, I use PB also. I found that impact works better for me than brute force twisting action. I take whatever wrench required, prefer boxed end for this, and a hammer. Rather than twist directly, I put moderate pressure on the wrench and then hit the end of it with a hammer....amount of wham depends on size of fastener. Once it moves, more PB and carefully move it back and forth until it gets to moving out of the hole....along with more PB and a little time, like move them all out at once, not get one out then the second and third and all...gives the PB time to soak with the repeated applications.

"racerone" grinds the heads off the bolts, removes the cover, soaks the threads thoroughly and then removes with a pair of visegrips. Never did that but if you can get to the heads to grind off, sounds like a good idea as you can get the PB on the threads better.

 

[utfyrfytr]

Anyone have any info on what hardness of bolts to use? Also thanks for the ideas guys I appreciate you sharing your knowledge.