johnson,evinrude lower units

[eric the fisherman]

i have a 1989 vro johnson,evinrude 120 hp with small lower unit case with 13 spline prop shaft. Will similiar year model v4 engines with small case lower unit 13 spline fit this engine ie 115,130 140 etc. Also what years would be compatable. any info would be welcome. Thanks

 

[AEROCOOK]

Re: johnson,evinrude lower units

The 1989 120 is a looper motor so according to the lower unit interchange list in the "top secret file", it should have a 15 spline prop shaft, not 13. Maybe the motor already has the wrong lower unit on it??

 

[eric the fisherman]

Re: johnson,evinrude lower units

The 1989 120 is a looper motor so according to the lower unit interchange list in the "top secret file", it should have a 15 spline prop shaft, not 13. Maybe the motor already has the wrong lower unit on it??

Dont know aero but looks original. Engine is on 18 ft javelin fish an ski. Turned about 6500 rpms an run bout 73 mph with 13 an half by 22 pitch prop. Thought rpms was high. Holeshot an top end was awsome.Tried to put prop on xp 150 evinrude but that was 15 spline an prop only 13. Know some models had big cases with 15 splines an some had small 13 spline. Like i said looks original but dont know for sure. This was way it was set up when i bought the boat.

 

[AEROCOOK]

Re: johnson,evinrude lower units

Well I'm no expert, I was just relaying what I saw in the top secret file, perhaps someone with more knowledge will pipe in.
I tend to agree with you on the RPM's though, I don't know what the max (desired) RPM is for a looper like yours but on my 110 crossflow, it's 5500 - 5800.

 

[eric the fisherman]

Re: johnson,evinrude lower units

Well I'm no expert, I was just relaying what I saw in the top secret file, perhaps someone with more knowledge will pipe in.
I tend to agree with you on the RPM's though, I don't know what the max (desired) RPM is for a looper like yours but on my 110 crossflow, it's 5500 - 5800.

didnt happen to mention in top secret file what would interchange did it. Im kinda new on the lower units.Would big case 15 off of v6 crossover or should i try a small case with 13 spline off similiar size engine .Far as i can get on my research is small case 13 spline will fit all v4 evinrude, johnsons from like 78 to 91. Think they redesigned lu cases in 92 but think they interchange up to mid 2000s.Just hate to spend the money an not get it rite. For some reason big price difference between 115,130 an 140 lower units and a 120 specifically.

 

[Dhadley]

Re: johnson,evinrude lower units

The looper V4s used the 4.25" gearcase (13 spline) and the 4.75" case (15 spline). It's not a true V6 case but the same outside dimensions. The small case works best on a V4 in most cases.

 

[eric the fisherman]

Re: johnson,evinrude lower units

The looper V4s used the 4.25" gearcase (13 spline) and the 4.75" case (15 spline). It's not a true V6 case but the same outside dimensions. The small case works best on a V4 in most cases.

I have the small case with 13 spline.Will a lower unit from 90,115,130,140 interchange with my 120 engine from say 1980 to 1991 as long as they to are small cases with 13 splines