Transom though bolts

[Jhoppy]

I have a 1971 1350 mercury with power trim tilt and need to know how many transom though bolts should be used when re-installing the motor. It was held on with only the screw clamps and lower two bolts in the engine mount bracket. I?m thinking it should have more bolts holding it on because there are several places to bolt through the motor and cylinder brackets. There are two slots in each of the power trim cylinder brackets and two holes at the top of each motor mount bracket and then a slot at the bottom of the bracket. How many bolts is common when installing This motor?

Thanks Hoppy

 

[Bob_VT]

Re: Transom though bolts

Four and I usually use fine thread, big washers and nylock nuts.

 

[jeffrobean]

Re: Transom though bolts

I have a 1971 1350 mercury with power trim tilt and need to know how many transom though bolts should be used when re-installing the motor. It was held on with only the screw clamps and lower two bolts in the engine mount bracket. I?m thinking it should have more bolts holding it on because there are several places to bolt through the motor and cylinder brackets. There are two slots in each of the power trim cylinder brackets and two holes at the top of each motor mount bracket and then a slot at the bottom of the bracket. How many bolts is common when installing This motor?

Thanks Hoppy

Are you using anything around the bolts? like a sealant or epoxy?

 

[Bob_VT]

Re: Transom though bolts

Bolts should be sealed with 3m4200 if you EVER intend on removing them. Silicone will fail and 3m5200 is a permanent sealant

 

[j_martin]

Re: Transom though bolts

If the transom is wood, and if you have a couple of days, treat the drilled holes with penetrating epoxy sealer, maybe two applications. Let the solvent evaporate thoroughly before you install and seal the bolts with 4200.

my 02
John

 

[Chris1956]

Re: Transom though bolts

The power trim brackets should have two bolt holes each. That is a total of six 3/8"bolts

 

[Jhoppy]

Re: Transom though bolts

Thanks for all the replies, and good idea on sealing the holes before installing the motor. I was thinking that there should have been bolts though the power trim brackets. Is the 5200 or 4200 the only sealers that can be safely used? I was thinking using the right stuff made by permatex it is an automotive silicone. Also I?m needing to reinstall drain plug tubes because I replace the transom would it be ok to use JB weld on them it says it sticks to wood and metal?

Thanks Hoppy

 

[Moody Blue]

Re: Transom though bolts

The 3M products (4000, 4200, 5200) are polyurethane adhesive/sealants. Polyurethane is superior to silicone in strength, adhesion and flexibility. Some silicone's are mildew resistant but I don't think that any of the polyurethanes are.

There are other manufacturers that produce similar products. Sikaflex is one of them. There is no one product suitable for all applications. Do your research and choose the product that best suits your application.

 

[trendsetter240]

Re: Transom though bolts

The 3M products (4000, 4200, 5200) are polyurethane adhesive/sealants. Polyurethane is superior to silicone in strength, adhesion and flexibility. Some silicone's are mildew resistant but I don't think that any of the polyurethanes are.

There are other manufacturers that produce similar products. Sikaflex is one of them. There is no one product suitable for all applications. Do your research and choose the product that best suits your application.

This is true and the best sealant for engine mounting bolts is 3M 4200. You only need a small tube of it for this job and it's not that expensive.

Also I?m needing to reinstall drain plug tubes because I replace the transom would it be ok to use JB weld on them it says it sticks to wood and metal?

Not sure exactly what you mean by drain plugs, are you talking about the ones in the splashwell? If so 3M 5200 is ideal for that application. (4200 will also work but will not be as strong.)