Good 1984 johnson 140 block

[j140head]

Thanksfor your responses!!

Ok, I believe what you are all saying is that most V4 crossflow internal parts (ie. crank, rods and pistons)parts are interchangeable as long as you have the correct crank seal assembly for your model year. as long as you match large or small split center bearing crank to same style block.
Can you take a small center berring crank (ie; 1977 or earlier) and put a large center berring on it?
Do I need to use the original upper and lower crank bearing assemblies from my block or do I use the bearing assemblies from a crank I purchase.
I also take it that I should use all of the original carbs and intake to the supply the needed fuel as well as the original flywheel and ignition components.
You are also saying that HP output of my 1984 140HP is the same as a 1995 115HP because the HP is rated at the powerhead vs the prop for later models.
What are your thoughts on after market pistons Vs OEM.

I just want to say thanks for all of your help, it is greatly appreciated!!!
Thanks, J

 

[ezeke]

Re: Good 1984 johnson 140 block

"Can you take a small center berring crank (ie; 1977 or earlier) and put a large center berring on it?" No, you cannot.

The porting on the blocks varies depending on horsepower; a 140 block is different from, say, a 90.

I would disagree with the statement that a 1984 140 is equal to a 1985 115 unless it can be demonstrated that every part is the same, which I don't believe is true. It may be true that at a given RPM the engines produce the same.

I spoke with the gentleman who is boring a block for me today. He prefers Wiseco pistons on the crossflows because he says the rings are less likely to catch. He also showed me the difference in porting between the 90 and 115. I was already familiar with the difference between the cylinder heads.

 

[Chinewalker]

Re: Good 1984 johnson 140 block

Hi Ezeke,
Sounds like my old block is going to work for you. I remember when I had a 90 and 140 block side by each and noticed the difference in porting. Those holes are HUGE in the 140!
I think J140 was comparing the 1984 and 1995 models, not 1985s. The 1995 115 is essentially the old crossflow 140, as they re-rated the 140 to 115 when they made the switch from powerhead to lower unit rating. The post 1985 115s got the bubble-back, etc. The big block blooper became the new 140...
- Scott

 

[ezeke]

Re: Good 1984 johnson 140 block

Excuse me J.

Hi Scott.

We think it might work. We welded the hole in the bottom of #4 and smoothed out the other holes. We are trying to cut the #4 cylinder at a slight angle and bore to 3.53. It may work. We talked about a new sleeve, but I think I am going to work with what I have. I will keep using the big loopers for my primary motors.

The crossflow is eventually going on a project center console to replace a 90HP Yamaha that was wrecked in the surf. I think I will use the 1994 ignition with the single rev-limiting powerpack.

W.

 

[Dhadley]

Re: Good 1984 johnson 140 block

Are you boring on a slight angle to the crank or slightly off center? Slightly off center will be OK, it's probably a little off now but be sure to bore straight to the crank centerline.

 

[ezeke]

Re: Good 1984 johnson 140 block

Thanks, we are holding the block offset slightly, but we are boring to the center of the crank. We are trying to use as much of the cut as possible on the scored side of the cylinder (port to head on #4).

 

[Dhadley]

Re: Good 1984 johnson 140 block

Excellent plan, that'll work just fine.