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1979 Johnson 140HP engine problems please help

R

Rjcamel2355

Contributing Member
I have a 79' Johnson 140, that I have been at my wits end with for the past few months. I cannot seem to get it to run correctly. Prior to this issue it ran great, and now it just refuses to cooperate with me.

Compression is: 130PSI on every cylinder
Spark: looks great really bright blue, every single plug.

I have changed: Two pistons (got water gas and melted two), timer base, stator, all coil packs, and power packs. I have rebuilt the fuel pump, new plugs, new reeds, swapped the intake, and the carbs ( to test). Crank seals, all gaskets from the bottom up.

I can run the engine on muffs or in a barrel all day long, rev it up, do whatever I'd like to it and it sounds and runs fine (or it did).

I put it in the water, start it, idles fine, sounds great. Once I put it in gear and accelerate 100-200 yards as it starts to pick up speed and get up on a plane it seems like it runs out of fuel (primer bubble is still hard, and the gas is still flowing) but it refuses to start back.

Yesterday, I tried to get it to fire off on muffs, and it did for a short time, but after running ( popping backfiring and all sorts of racket) it died, and wouldn't start back even after cranking on it (working the timing adjustment, and carbs) to try to get it to start back. Nothing.

Holding you hands over the front of the carbs you can't feel much if any air being pulled through them.

Any suggestions would be wonderful, because I am at a loss here....

I have yet to do a cylinder leakdown test on it, and that is my next step.
 
Flywheel properly torked ?---------Checked the flywheel key?--------Were the rod caps properly lined up before torking to 370 inch-lbs ?
 
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Everything torqued properly and aligned. Primer bulb doesn't stay rock hard but it still has pressure in it. I've been told possibly the crankcase or seals sucking air would cause something like this? Is that a possibility? I put it back together with ultra grey, was told anaerobic sealant is the proper substance to use.
 
Flywheel and key are In good shape and properly torqued down. It backfires and pops which sounds like a timing issue but I've tried a known good set of triggers coils and power packs.
 
Well a sheared key will throw it out of time.-----Nothing else will.--------Are the orange wires going to the correct coils ?
 
It sheared a key prior to this and I replaced the key. Wires are going to the correct coils. When I initially started having problems I could only get the engine to run correctly with the cowling off. That's when I began replacing everything in an attempt to fix the issue
 
Only a factory key is to be used !----------Did you replace the plug wires and boots ?------They can and will short to the cowling latches.-----Throwing parts at a problem does get expensive in a hurry !!
 
Factory key was used yessir. Its getting to be very expensive. As mentioned the carbs don't seem to be sucking air into them. And I'm just making guesses at this point. But back firing usually points to out of time on a car engine. There is raw fuel coming out by the property a black soot looking colored liquid. The plugs are firing hot, but it refuses to bust off and run. I'm just at a dead end I have no idea what else to test or try or replace .Good compression good fire. It should run.
 
Won't run with the choke on. Won't start even holding it wide open throttle. With it not running before unless the cowling was off it made me wonder about not getting enough air. Or the base gasket leaking. I replaced that gasket but the same symptoms were occurring. Usually on the lake when it died I would swap the plug wires on the starboard side .Crank it until it hit once swap them back and I could get it to run 100-200 more feet then the same problem. I have never seen one act this funny
 
Mark top dead center for each cylinder on the flywheel when piston is at the top of the cylinder.-----Use timing light to test timing on each cylinder.-----------Using a sealer that has too much filler in it may result in improper assembly of the metal to metal joint on the crankcase.-------The proper filler should almost all squeeze out of the joint for proper clamp up of the bearings.-------The center crank bearing was properly located on the dowel pin ?----Any damage to the flywheel and crank tapers.--Have to ask since I was not there when motor was assembled.
 
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Something is drastically wrong if you are swapping plug wires to try and get it to run !----------How have you checked the flywheel key today ?
 
Ultra grey was used to seal it all up. Which I know anaerobic sealer is the correct stuff. I personally just watched the assembly. The mechanic who rebuilt it for me 6 years ago re assembled everything and said it looked fine and would run fine (after replacing the two pistons and rings) he's also at a loss and keeps assuming it's leaking around a crank seal or the crankcase. No damage to the flywheel I'm positive on that
 
I haven't put my eyes on the key today, but I will just to make absolutely sure of it. I had it off yesterday (the flywheel), and was 99% sure I put it back together correctly. (I was only swapping the plug wires to get it to hit that one time, ), part of the reason I swapped the triggers, because I thought there was an issue with them... So far I've narrowed out the stator and triggers (I have a parts motor, so I have basically everything I need, if I have to swap anything.) I have checked the coils, powerpacks, and have replaced the plugs, and the plug wires. The plugs are wet when I pulled them out (after cranking it over several times), and when I pull the plugs to check for spark i am getting plenty of spark through them. I traced each individual coil, and plug wire to make sure they were going to the proper cylinder ( I replaced both packs, all the coils, and plugs yesterday) Still having the same issues.
 
As of the last time I tried getting it to start:
It would not start, it would continuously crank, occasionally backfire, but would never act like it wanted to run.
Around the lower unit/prop there was black-ish liquid (which I am assuming is unburned fuel exiting the exhaust).
*All plugs are firing, bright blue spark
*Coils and to the correct plug, not jumping fire anywhere (tried at night to visibily see if that was an issue).
*Keyway in the flywheel was properly seated, and flywheel was properly torqued.
* 130#'s of compression on each cylinder.
* Attempted holding throttle wide open, and rocking the timer base linkage to get it to bust off, did not help at all.

Earlier in the day WHEN I did get it to start, revved it up, backfired/popped and died, then it wouldn't start back up.
Carbs have been cleaned, reeds have been replaced.


When the engine was pulled apart:

*Replaced the crank seals (top and bottom.
*Replaced two pistons, and rings.
*Replaced timer base, stator, coil packs, timing triggers.
*Attempted swapping carbs, and intake from a known running good engine.
*Replaced intake gasket, and powerhead base gasket.
*Sealed crankcase with silicone Ultra Grey Permatex
*Followed all torque patterns/#'s
*Replaced head gaskets
*Rebuilt fuel pump
*Replaced copper tube (water tube)
*Removed exhaust (bubble back cover) and determined the filler blocks were DONE (Broke, melted, cracked) and left them out (was told this would not hurt, and would only increase engine rpms around 150rpms).

I was going to just swap the powerhead from my parts engine, but during a compression test discovered it only carried 120,120,120, and 60#'s on the cylinders.
 
I rebuilt the fuel pump, but I do have another one to swap them out. I haven't tried that yet. If I do end up tearing back into it I'll be sure to use anaerobic sealant
 
Could it possibly be a bad seal ring on the crank case? I replaced one when putting the case back together (broke it during the installation) and maybe it didn't completely compress the new one? Just trying to go over everything I did in the process, and narrow things down. I do intend on a complete teardown, re torque and seal everything (correctly, anaerobic sealant, and gaskets). But would this cause issues like those that I am experiencing?
 
Tearing it down mid-next week, I recall sealing the case, but I didn't have the "spaghetti seal", order a complete gasket kit, and will start from the bottom up, checking everything closely. If at all possible, could someone point me in the direction of a reliable torque spec guide, and/or manual? I can't recall where I got the specs last time, (I would even be interested in purchasing a manual, paper or pdf).

Thank you, I will post results/pictures if I find anything.
 
The " spaghetti seal " is shown for 78 models but not the 79 model.--------You did all this work without a manual of any kind ?
 
I believe the block has been replaced .Title says 79 block seems to be 78. I personally haven't done the rebuild I have just watched it and disassembled it. The guy re assembling and guiding me is certified and has been rebuilding the for 20+ years. I would like a manual myself though. He does it just from experience
 
The guy re assembling and guiding me is certified and has been rebuilding the for 20+ years. I would like a manual myself though. He does it just from experience
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He shouldn't have let you use silicon....
 
I'd have to take blame on that. Trying to rush getting it finished, didn't use the spaghetti seal, and silicone. I'm sure this probably has something to do with my problems.

I'm trying to recall, but last year when this all began .I ran it for 2-3 hours a day or two after the rebuild and it ran amazingly. And this all began shortly thereafter, I'm sure the silicone probably didn't hold up well. It's time to open it back up and seal, gasket, and torque everything to the exact factory recommendation.

I would love the torque specs for the crankcase .If possibly, I'm sure everything inside that is fine but I'll check it anyways.

Prior to these issues I ran boysen 2 stage reeds, will I notice much of a difference in these and the stock reeds I went back with? (A few had a little gap so I swapped them)
 
I am not a fan of Boyeson reeds as they only last a few years,a lean sneeze burns or breaks them,they warp as you have seen and you have to rejet idle mixture to use. The only difference you will see is they improve idle and mid range.I use use TDR and CCM reeds in my customer motors and never had a complaint...
 
faztbullet said:
I am not a fan of Boyeson reeds as they only last a few years,a lean sneeze burns or breaks them,they warp as you have seen and you have to rejet idle mixture to use. The only difference you will see is they improve idle and mid range.I use use TDR and CCM reeds in my customer motors and never had a complaint...
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I will be the other side of that I use boyesen reeds in all my engines. Some of my motors have been running them for 10 yrs plus and are as reliable as any of the other reeds out there. But FATZ is right about one thing set-up is critical to those, most people just throw them in with out doing the set-up. They run it and they fail in a couple of years then the reeds gets blamed.
 
The guy rebuilding it just happened to have them and threw them in the engine during the rebuild (the initial one 4+ years ago), didn't know anything about them, just heard they added a little more rpm's. They were cracked open a VERY small amount when I pulled them out during the beginning of all these problems. I cannot say anything bad about them, this motor was ran 6500-7000 rpms regularly (Yes, I now know that isn't good for them at all, and have since went to a 22P prop.)

I'll probably run the stock reeds for a little while, and then hunt up something different if they don't fit what I'm wanting.

Just hoping to get everything together, correctly and if all goes well be sitting on the lake next weekend.

140HP V4 bored .030
14' tidecraft Boat
6" Jackplate
22P Rakker prop

It should run pretty good for what it is. (I haven't even got the turn the prop, or have it run correctly since the jackplate)

I really do appreciate the input and time/suggestions from everyone. I've ordered a manual to look over and read up on during the process also.
 
Just an update on all of this:

Tore into it over the weekend, resealed the crankcase with the RIGHT STUFF (Anaerobic sealant, and some rope seal). Everything internally was clean as could be. Bolted it all back together.

Set it in the water, and had a little trouble (fuel filter inside the tank came loose, and sucked up some trash).

Installed inline fuel filter, and cleaned the carbs thoroughly.


Runs like a bat out of... well you know. Very impressed, lesson learned. Take your time, use the right stuff.


A big thanks to everyone for tips, suggestions, and every post.
 
Well, Guys back at it again.... Went to run it for an extended period of time (go fishing). Got out on the lake, up on a plane and it began "surging" if I pump, or hold the primer bubble it'll act a little better, but it still won't run WOT, it acts as if it is running out of fuel. I tried using a different fuel pump (not new, but different) and have the same symptoms. Cleaned the carbs and checked them over. They're in sync, good fire, good plugs. Primer bubble goes "soft" when running, I can pump it back up or squeeze it and force more fuel through it, but it only helps for a moment.

My question is, is this most definitely in the fuel pump?

Can I bolt a automotive electric fuel pump to it and it work?


It runs great WHEN it isn't surging.
 
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