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1982 e75trlcnb swap

L

Lazeronu

Contributing Member
Hello all,

my 82 75hp evinrude blew up and I found a 1989 70hp Johnson. Was hoping to get some guidance on whether not it would fit if I swapped the powerheads. Would the bolt pattern and gaskets match?

I would transfer all power/controls etc from each respectively.

Thanks in advance.
 
If it's an option keep the 1989 70 hp motor all together it's a much more powerful motor than your 75 hp. They are 2 different blocks the 89 is built on the 56 CID block. Your 82 block is a 49 CID block. Also the driveshafts are different as the splines in the crankshaft were changed after 1988 from a 4 spline to I believe 13. The controls are an easy swap.
 
Is it possible to replace my current 82 lower end unit drive shaft with a 13 spline. The motor in which I am looking at had the lower unit badly damaged and does not come with a lower unit.
 
No unfortunately the lower unit was completely removed from the motor. It is in a shop right now but the mechanic said it would. E best to replace with a new lower unit.

I have a perfectly fine lower u it from my 82 and was just hoping to be able to use that as that was rebuilt less than a year ago. But it seems due to the spline difference of the drive shafts I cannot just swap the powerheads/motors. If I could get ahold of a drive shaft could I swap it onto my 82?
 
Yes, the fine spline shaft will fit into the 82 lower unit.----------------BUT, you have to select the proper shims for long gear life.----------It is NOT plug and play.
 
You may also be able to bolt the 82 lower unit onto the 89 midsection once you get a driveshaft And use the 89 motor. I would check that out also because it's easier to swap lowers than powerheads. Now I have only heard this can be done, because they changed the castings in 1989 also but worth a try for sure. I would also call the shop that has the lower because it may only be the gears that are bad may be able to save the driveshaft.
 
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The mounts studs are bigger in the 89(3/8) vs the 82(5/16) so you would have to swap adaper plate and drill your midsection...
 
One last swap question.

I am going to look at a 1985 Johnson 70hp with manual trim. The lower unit has water in the oil and would require some repairs, compression is 120 across all 3 cylinders, spark is solid.

My current 82 with blown powerhead has power trim and a good lower unit. If I were to pull the trigger on the 1985 motor would it be plug and play on my 82 (from what I've researched t is)? Would it be best to swap power heads so that I can keep power trim? Can my current power trim work on the 85 motor? What would be the easiest way to keep power trim and swap the powerheads? Do the controls plug and play?

thanks again!!!!
 
Your tilt and trim will fit right onto 85. Then just put your lower unit on it and go. If the 85 still has the original VRO pump put the pump from you 75 hp on it and continue to premix.
 
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Thank you. Much appreciated with all the quick replies. I will double check compression and spark and if that is good I will be up and running for spring :)
 
Ok purchased the 1985 Johnson 70hp.

Can i swap all wire harness/connections? The VRO pump is already bypassed but the coils and the choke are different. Maybe an extra wire from the stator as well?

also could I just cut the my wire barness and rewire to it runs from the big "red" plugs.

The current wire set up is a huge mess and was hoping to clean it up by just swapping from my 82 75 evinrude. I guess I would ask but it does look like some things won't match.
 
Get a wiring diagram for the 2 motors and compare them. You should be able to put the wiring harness from the 75 onto the 70 hp with no cutting. You may have to splice in for the tilt and trim power wires. The 85 would have come with a red plug originally. They use the same stator and the choke wire from the 75 will now run the primer on the 70 hp
 
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