Narrow mounting holes on old Merc

[mildewing]

I just got a 1982 Mercury 115hp. I just noticed that the mounting holes are narrow. This motor may not stay on my boat because it only has 85-88 psi on all 6 and i have run it yet. Do i have any inexpensive options besides drilling new holes?

 

[GA_Boater]

Before worrying about drilling holes, which you have to do and no way around it, build a stand so you can run the motor and getting it running well first.

Check this thread - https://forums.iboats.com/forum/eng...680-building-an-o-b-motor-stand-instructional

 

[mildewing]

Thanks for the reply. I did build that stand before i went to pick up the motor, this site is great.

I was afraid i would have to drill new holes but was hoping maybe some kind of jack plate adapter or something would work for a test drive. I am worried that i will get the motor running good on the stand to find out it lacks power under load.

I still have about a week until my transom replacement is complete. The tilt tube has the old steering froze in too so i need to replace that before it goes on the boat. Starting to wonder if maybe this motor wasn't the best option, even at $100.

 

[GA_Boater]

100 bucks! If you get her running it may be a good investment.

Sounds like the motor has been sitting for a while. See if compression improves after getting it to run, then you can make the decision.

The original motor used the BIA standard mounting as newer motors use and a jackplate would too. A jackplate would need drilling on the motor side to mount the motor. Mercs switched over to BIA mounts, but it was phased in and I'm not sure when.

 

[Scott Danforth]

mid 80's is when the mounting pattern standardized

 

[mildewing]

Thanks. I will start a new thread when i try and get the motor started. There is at least one burnt wire i will need help with.