1997 Johnson ocean runner 115 lower

New to the forum, and new to outboards. I was gifted an mid 90's Lund with a 1997 Johnson 115 ocean runner J115SLUE with 60 degree lopper block. The motor has a Jet on it and I am trying to find a lower unit to go back on it part# 5004632. A guy locally has a lower 20" from a 1997 Johnson with a 90 degree block. Are the lower units the same for 1997 90-115hp regardless of the block?
Thanks in advance!

Upper driveshaft and shift rods may be different.-----Lower unit is different but will fit.------In fact the " crossflow " lower unit may be more robust then the " looper " lower unit.-----You would need another driveshaft shift rod to make this work.----Easy to research on this site for part numbers.

I would probably end up rebuilding whatever lower I would get anyways, I just need to know for sure before I hand someone $400.

Might as well get the correct looper lower unit I say.------All the parts will be a direct swap.----Or an aftermarket SEI lower unit at about $1000 brand new.

Is the jet broken?

No idea, Probably not since it wasnt used that much. It's just not needed for what I will use the boat for (going up rivers) plus a riveted aluminum boat is not a rock jumper like some of the NW welded aluminum boat anyways. Isn't there also a power loss of like 15% with a jet.

To place a percentage of efficiency is difficult. The wrong prop can easily cost you 15 percent as well. True, jets have their place and by comparison have a safer history as well as less moving parts. I can't begin to list the repercussions of a hard rock strike with a stainless steel prop. I repair props and skegs, sometimes the prop repair itself is just the "tip of the iceberg". This rock strike cost my customer about 2000 bucks. That is the same housing, before and after. Prop shaft was bent. Driveshaft and even crankshaft damage is not uncommon.

PNWball3 said:

No idea, Probably not since it wasnt used that much. It's just not needed for what I will use the boat for (going up rivers) plus a riveted aluminum boat is not a rock jumper like some of the NW welded aluminum boat anyways. Isn't there also a power loss of like 15% with a jet.

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It's more like a 30% difference between a prop driven O/B and a jet driven. Basically, this 115 will run the boat about equivalent to an 85HP. On a riveted aluminum boat, is that really that much of difference to worry about?

Personally, if I were going to run rivers exclusively I would stick with the jet drive since it's already on there. This allows you to run much shallower water and eliminates the possibility of slamming the outdrive on unseen underwater obstructions. Sure you might run in marked channels, but what logs and other junk are lurking under the surface that's moving with the current?

I'm sure your thinking about this from a performance/speed perspective. I'd say first run the boat and see how it performs. If speed, holeshot, ride quality, etc. are just awful then start looking for a regular LU to swap on. But, if all of those are okay then I'd just go with what you have and save the $$ for bait and tackle.

KJ

I have a Lower unit from a 60 degree 115 looper that I could sell you pretty cheap to make the wife happy. It was from a long shaft (or extra long 25"). On the longshaft they used a beefier lower unit. They also had a larger prop shaft diameter, same as the v6's. I have no idea what shipping would be. I live in Florida.