1983 115hp johnson

[jc44]

I have a 1989 evinrude 110 hp with a bad cylinder which I'm thinking of replacing with a 1983 115hp Johnson motor.
Can anybody tell me if these motors are basically the same and have interchangeable parts and did they rate the horsepower the same? The Johnson has 120psi on all cylinders. The only thing I'm concerned about is there is a small hole in front of the lower unit. New to the site would appreciate any feedback. I'll try and post a picture of the lower unit.
Thanks

 

[Faztbullet]

Re: 1983 115hp johnson

Same engine ...the 110 is a 115 without the VRO and new style elecronics...

 

[emdsapmgr]

Re: 1983 115hp johnson

The powerheads were rated differently. The 110 was rated at the propshaft, the 115 was rated at the crank. The crank rated engine would actually be about 15% lower-when compared to the later 110, or about 100 hp. It will be hard to notice that slight difference.

 

[jc44]

Re: 1983 115hp johnson

Thanks for all of the information, I'm still trying to send a picture of the lower unit which has a hole in front of it. Could this be a speedo pickup? and are the lower units interchangeable? if so what year range are the parts interchangeable?


Thank you,

 

[jc44]

Re: 1983 115hp johnson

This is the picture of the lower unit, can anyone tell me what this hole is for?
Thank you,

 

[wired247]

Re: 1983 115hp johnson

One has the bubble back exhaust ( the 110 ) and the other doesnt. Johnson HP rating bore zero resemblance to reality so dont get too hung up on that. Prop nor crank rated they were still completely wrong and picked out of thin air.. Same ports, compression and likely almost the same jetting of carburetor between the two.

 

[wired247]

Re: 1983 115hp johnson

View attachment 135728 This is the picture of the lower unit, can anyone tell me what this hole is for?
Thank you,

Its a drain hole.

 

[jc44]

Re: 1983 115hp johnson

Not clear on what you meant, are you saying that there isn't much difference in the HP rating between prop and crank? Thanks,

 

[wired247]

Re: 1983 115hp johnson

The 110 is essentially the later 115. It Is also the crank rated 140 with reduced compression heads. The 140 was never actually 140 HP so even calling it a 140 is misleading. I like to think of those numbers as model numbers more than any reference to actual HP numbers. As far as the difference between crank and prop numbers think of it as a garbage in/ garbage out sort of thing. The numbers are meaningless.

 

[jc44]

Re: 1983 115hp johnson

Thanks for all your help!! I have been debating whether to rebuild the Evinrude, most of the people i talked to said it wasn't worth rebuilding, Besides for the one cylinder its a really clean motor. The Johnson motor that i am looking to buy isn't in the best shape but it runs and has good compression. What do you think, buy the Johnson and save the Evinrude for parts?

 

[jc44]

Re: 1983 115hp johnson

bought the 83 115 johnson yesterday, do have a question though. checked compression when motor was cold ,all cyclinders between 105 to 125. warmed motor up and checked again, readings were 5 lbs. lower across the board, any concerns. was told that warm motor gives more accurate readings. any info appreciated, thanks.

 

[emdsapmgr]

Re: 1983 115hp johnson

You originally said the compression was 120 on all 4 cyls. Normal on that 115 block is probably around 125 when new. It's acceptable to have a 10% variance between cylinders. Your 105 figure is starting to crowd the low-below the "normal" tolerance. It is possible to have a 5-6 lb variance between the two heads-due to manufacturing techniques when first bored at the factory. If you are concened, you might pull the low compression head and check the cylinder walls for scuffing, the head/piston crown for pitting. If everything checks out, put a new head gasket on it and go boating.

 

[ezmobee]

Re: 1983 115hp johnson

I was under the impression that many compression testers weren't particularly accurate with regards to the actual number being returned, but they are consistent. So they're a better tool for checking variations between cylinders. I don't know that I'd go tearing into it unless there's an obvious issue. I defer to the experts though.