1981 Mercury 7.5 2 stroke

keithb7

Recruit
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Dec 16, 2024
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2
I recently purchased a used 1981 7.5 hp outboard. I plan to use it with a small SIB. I am new to outboards but not new to mechanical repairs. I’ve rebuilt multiple other types of 2 and 4 stroke engines. I tend to source an OEM service manual ASAP. I’ve not found one yet but I will.

Is anyone able to tell me what year did Mercury start using the breakerless spark box on the 7.5? I might pick up a spare parts engine or two. Prefer years that are very similar to my ‘81.

I also curious to learn how many cc’s the engine is. If you have a manual you’ll sell let me know. Thanks. Keith
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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49,755
you can get the manual from Mercury or find them on-line at sites like oldmercs or AOMCI for the 7.5/9.8. look at the 1980-1985 motors as they are all the same.

the first thing you need to do is pull the leg, measure the vertical drive shaft diameter, then order a raw water pump kit. the reason you have to measure the driveshaft on that motor, is it could come with one of two sized shafts.
 

keithb7

Recruit
Joined
Dec 16, 2024
Messages
2
Thanks. I will try those web sites.
I have already pulled the lower leg measured, the shaft and ordered a water pump. Its on the way.
The thermostat was removed. I also ordered one.
 
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