1977 Johnson 140 V4 -- Ring trouble!

[The Wasp]

Hello all,

I'm new to the forum here -- I have a 16.5' CeeBee Avenger with a Johnson 140 outboard (1977). I've only owned the boat about 1.5 years and do not know about it's maintenance history.

It was running kind of poorly towards the end of last year and this season also. I got it running consistently at about 30%+ throttle, but it refuses to idle and noticeably runs rough at lower rpms.

I took it to a local boat place (Middleton, WI) a couple of days ago and just found out that it, apparently, has torn up one of the rings. I know enough to realize this is not good, but I need some advice beyond that.

I want the engine to be reliable. I'm not concerned about power (140 is more than plenty) and I don't want to spend a ton of money.

Is this the kind of problem I can fix myself? Parts are for sale online. I have never rebuilt an engine, but I am a bit mechanical.

Is it likely I would have to replace a piston along with the ring?

Can the engine be disassembled (enough to replace rings) while mounted on the boat?

I see pistons and rings online (for example: link). Looks like $69 for a piston and $27 for a ring. Are there many other costs involved that might come into play? Maybe some gaskets?

Any recommendations would be much appreciated. Thanks so much

 

[emdsapmgr]

Re: 1977 Johnson 140 V4 -- Ring trouble!

Any ring work will require a complete teardown of the powerhead, including splitting the block apart. That's a bench job. When you get it apart, you will need to determine the condition of the cylinder walls, esp the one with the bad rings. Depending on cylinder wall taper and the degree they are oval-shaped, you may have some options: Bore all cylinders to an oversize and install new pistons. Bore one cylinder oversize and install one new piston. Hone all 4 cyls and get one new standard piston. In any teardown you will need all new rings for sure. You will need the factory service manual and a reputable shop to check/bore the block. I don't recommend reusing the head on the side of the failure, as it will be all pitted. The hardest part will be trying to find a replacement head. You will need a powerhead gasket set. Bombardier oversize pistons come with a ringset in the box. Additionally, at point of overhaul I would install new thermostats, new impeller and overhaul/clean both carbs. You don't want to have a problem with a new powerhead when you get it running again.... I'd pull that carb apart the feeds that bad cyl and go looking for dirt or fuel restrictions in side that barrel. You should determine the root cause of the failure.

 

[rtek816]

Re: 1977 Johnson 140 V4 -- Ring trouble!

Wasp,

I am close to running my 1986 140 that I've been rebuilding over the last couple of weeks (first outboard rebuild). I had the same problem as you as 1 piston gave up a 1/2" piece of the top ring and banged the crap out of the head. I have mechanical ability and found a ton of info on this site to help me through the unknown. Take a lot (and I mean alot) of pictures before and during teardown. They will help immensly. I've wrapped about a grand into doing this rebuild myself. A rebuilt power head online is around $2,500.00 plus installation. I figure I'll have saved about that much doing it myself as well as have the satisfaction of knowing just about everything about this engine. I run it on a 21' center console Starcraft. I only replaced the damaged piston, rings all around, rod bolts, rod bearings, center main bearing, gasket set, carb kits, all new recirculating hoses, thermostats, fuel/primer lines and air silencer gaskets and a few misc. parts that were required. The long part was waiting for the parts to show up that I missed on my initial order. I purchased a used head from Joe Reeves off this site. I was able to keep all cylinders standard size and a light hone cleaned all the holes well. I should have it fired up in the next day or so as soon as I figure out how to torque the flywheel down to 140 ft. pounds. Bob

 

[The Wasp]

Re: 1977 Johnson 140 V4 -- Ring trouble!

Thanks for the feedback, guys.

What are reasonable guesses on what a boat shop would charge for a powerhead rebuild? I have read some comments suggesting around $1800 -- is that a high, low, or normal price?

It looks like a 'complete' rebuild kit can be purchased online for $1025.

 

[emdsapmgr]

Re: 1977 Johnson 140 V4 -- Ring trouble!

What is included in the $1800? Labor only or are parts included? Is boring all 4 cylinders and 4 new pistons/rings included? Does it include new stats, a new impeller and a new fuel pump-all good components to change when doing an overhaul.

 

[The Wasp]

Re: 1977 Johnson 140 V4 -- Ring trouble!

I don't know what's included in that -- that's just a price I saw on a forum similar to this one.

I'm just trying to figure out what a typical range would be so I'm not surprised when I go and talk with the mechanic tomorrow.

 

[The Wasp]

Re: 1977 Johnson 140 V4 -- Ring trouble!

I considered my options and scoured Craigslist. I came up with a 1979 Johnson 85hp engine (85ML79) for $200 (+ a 3-hour drive to go pick it up). The engine included throttle cables, control box and wiring.

I was quite pleased to find that almost everything is interchangeable between this engine and my old engine.

I was able to keep the old electric tilt/trim and transom mount. I was also able to keep my control box, ignition wiring and throttle cables. I was even able to install the brand new prop I just bought on the 85hp engine.

To those that say 140hp to 85hp is a big drop...that's true. My boat is rather small, though so while the potential horsepower is less, 85 is still plenty to enjoy. My dad and I did the engine swap last night and fired it up this morning. Had it out on the lake in less than 24 hours after purchasing the engine.

One thing that is not working is the electric choke. The original wire was cut for some reason and they spliced in another wire instead of connecting into the original wire harness. I tried testing briefly and it looks like the choke solenoid may be no good. I was disappointed to see these solenoids are hard to find and not cheap.

Does anyone know where I can get the solenoid at a good price? Are there any interchangeable/replacement part numbers I can use instead of the original 0581929? I think I can get the engine running without choke -- but it would be best to use it and I'd prefer not to have to take the cover off to work the manual choke.