Johnson 115 or 140?

[JOHNSON140HP]

I just bought my first boat and i am new to iboats.I wanna do a tune up on the engine.The cowling says its a 140 also the engine mount says 140 also but this little circle on top of the engine says 115 in the serial number im confused can anybody help?

 

[boobie]

Re: Johnson 115 or 140?

Looks like you have a 115 hp ph. A lot of hanky-panky goes on in the area we're both from.

 

[JB]

Re: Johnson 115 or 140?

Looks like the 140 powerhead was replaced with a 115 powerhead, J140. Maybe you need to change your handle to "JOHNSON 115 under cover".

Servicing could be difficult until you know what other parts (beside the 115 short block) were substituted.

 

[wired247]

Re: Johnson 115 or 140?

You have a 1978 115HP powerhead. The exhaust cover is a 115 piece as is the tag. Its also obvious that the engine has been cobbled together from different parts. 140's use different heads, a machined internal exhaust passage, a different exhaust cover and internal exhaust passage set and they have a set of rubber stuffers inside the intake manifold. Someone probably blew up their 140 and replaced it with a 115 powerhead. These things are 30+ years old and 140's never did grow on trees.. My 140's block has been replaced with a 115 block that has been machined to 140 specs but it still has the 115 tag.

A 140 ( and later 115's,112's and 110's ) will look like this from behind.

 

[JOHNSON140HP]

Re: Johnson 115 or 140?

What a pain in the butt.I guess i will figure it out i'm gonna bring the boat to a local marine shop and ask them to look at it so i can figure this out thanks guys for the input oh yeah can i change my username i don't want to be a poser?

 

[JOHNSON140HP]

Re: Johnson 115 or 140?

I know one thing she runs good and starts on a dime and idles beautifully although i haven't put her in the water yet hopefully this weekend that's the real test.

 

[JOHNSON140HP]

Re: Johnson 115 or 140?

You have a 1978 115HP powerhead. The exhaust cover is a 115 piece as is the tag. Its also obvious that the engine has been cobbled together from different parts. 140's use different heads, a machined internal exhaust passage, a different exhaust cover and internal exhaust passage set and they have a set of rubber stuffers inside the intake manifold. Someone probably blew up their 140 and replaced it with a 115 powerhead. These things are 30+ years old and 140's never did grow on trees.. My 140's block has been replaced with a 115 block that has been machined to 140 specs but it still has the 115 tag.

A 140 ( and later 115's,112's and 110's ) will look like this from behind.

I will take more pics tomorrow of the engine after work .My boat is at a buddy's house so maybe you can help me more

 

[wired247]

Re: Johnson 115 or 140?

What a pain in the butt.I guess i will figure it out i'm gonna bring the boat to a local marine shop and ask them to look at it so i can figure this out thanks guys for the input oh yeah can i change my username i don't want to be a poser?

They'll figure out its a 115 because its a 115. If you took a 140 and put that cover plate on the exhaust you'd have a 115. As it stands you have a 115 stamped block with 115 accesories. You don't get much more 115 than that. The 115 and the 140 had identical bores , pistons, and block porting. You can turn that 115 into a 140 but its going to require some machine work and a few parts.

 

[Chinewalker]

Re: Johnson 115 or 140?

And, in truth, unless you're running on a lightweight performance hull, you probably won't notice much difference in performance between a 115 and 140 from that block. The 140s were always a little tightly wound without much room for error, so keeping it a 115 will likely give you better service in the long run...

 

[Dhadley]

Re: Johnson 115 or 140?

The "tune up" parts (Champion spark plugs) will be the same for either motor.

 

[glenn property of pam]

Re: Johnson 115 or 140?

dont fell bad my 140 evinrude turned out to be a 120. if it runs well and its your first boat i dont think you will be upset. think of it more as a de-tuned 140 that will last longer than a wound out motor

 

[wired247]

Re: Johnson 115 or 140?

And, in truth, unless you're running on a lightweight performance hull, you probably won't notice much difference in performance between a 115 and 140 from that block. The 140s were always a little tightly wound without much room for error, so keeping it a 115 will likely give you better service in the long run...

The 140 crossflow isnt just a wound up 115. Same ports and same power band. Just bigger carbs (sometimes ) , better intake flow, higher compression and more efficient exhaust in the 140. A good 140 should last just as long as a 115.

 

[Chinewalker]

Re: Johnson 115 or 140?

Not saying it can't last as long as a 115, but there's just less room for error. Squeezing 140 ponies out of 99 crossflow cubes is nudging the upper boundaries.

 

[wired247]

Re: Johnson 115 or 140?

The real problem with the 140's isnt the engine itself. They are very strong runners and will live all day at 6000 RPM. The problem is that many were installed on large boats with props incompatible with their power range. Running a 3000 lb 24 foot fishing boat at 2500 RPM with a 24 pitch prop for hours at a time is the perfect combination to killing a 2 stroke powerhead.

For small lightweight boats that will get run fast they are great engines and that 140HP can get boosted up considerably with a little port work. I often look back at mine and I have a hard time believing I'm going that fast with that little motor.