1984 70hp 2stroke yamaha lower unit swap with a 90 hp

[jimbad]

Hi, I have a 70 hp 1984 yamaha ETLK. The lower unit is bad. I found a 90 horsepower a similar year that I can get the lower unit from. Are these lower units compatible ? Can I use the 90's lower unit on my 70 ? If so and I do swap them is there anything I need to do other then bolt it up ? Such as shims or anything or does it just simply exchange ?

 

[99yam40]

Re: 1984 70hp 2stroke yamaha lower unit swap with a 90 hp

look up the part #s of both to see if they are the same

 

[boscoe99]

Re: 1984 70hp 2stroke yamaha lower unit swap with a 90 hp

The part number for the assemblies (complete lower unit) are not the same. However,

both of the housings are the same part number. So, it is presumed that a 90TLR gear case will fit a 70TLR motor. However,

the gear ratio for the 70TLR is 2.33/1 whereas for the 90TLR it is 2/1. Therefore, you might have to change the propeller to one of a lesser pitch.

 

[b10doyle]

Boscoe99, I'm wondering if you ever ended up doing this swap? I was told that my lower unit is bad on my 1987 70hp ETLH 2 stroke, and I'm wondering if there are any other lower units that would work if I have to go the used route.
Thank you.

 

[GA_Boater]

Boscoe99, I'm wondering if you ever ended up doing this swap? I was told that my lower unit is bad on my 1987 70hp ETLH 2 stroke, and I'm wondering if there are any other lower units that would work if I have to go the used route.
Thank you.

He hasn't been here in a year and a half.

Closed.