1985 johnson 140hp V4

[sred137]

The motor starts fine.Then when getting up on plane sputters for a second then seems to clean itself out and run smooth as can be.At idle it seems to be loading up and begin to stall if I don't put it in neutral and rev it up.When I rev it up it smokes like crazy.I did some searching and found that the line that is feeding the carbs was cracked and changed it,but have not ran it since.When I took off the plastic cover that covers up the carbs. it had about a cup of unused fuel.The crack that was in the fuel line was to the top of the VRO pump and was minor.Enough to possibly suck air but not enough to dump that much fuel.

After running the motor and inspecting the plugs.They are equally fowled.I will be running the motor this weekend to see in the change in the fuel line fixed my problem,but any other suggestions are very welcome.

 

[bktheking]

Re: 1985 johnson 140hp V4

First I'd try it seeing as how you did a line repair, if that didn't fix it seems like your carbs are loading up, remove, clean, rebuilt with new kits for starters.

 

[kenmyfam]

Re: 1985 johnson 140hp V4

Try it again for sure after the repair you did. Beyond that do the basic health check.

Compression
Spark
Fuel delivery
Spark plug condition

Post your findings and go from there.
I have the same motor and really like it.

Welcome to iboats

 

[sred137]

Re: 1985 johnson 140hp V4

Thanks for the responses.I love this forum.I live in ohio and I am a duck hunter.I will be using the boat on thanksgiving morning and will post back with the update.

 

[tal]

Re: 1985 johnson 140hp V4

Here's what I've found in the short time of owning my 85 120hp. About the fuel in the silencer, I've noticed that if I trim my engine up fuel will eventually come out of the carbs and go into the plastic housing. The gas kind of evaporates out and leaves oily muck in there. This has happened with 3 different float bowl settings I've tried so far. These settings ranged from what the manual calls for to 1/8" lower than that setting, all producing the same results. Also make sure your gas tank is vented or disconnect the fuel line when not in use.

Mine too was smoking a lot because it had set for years without running. I had higher compression on one side of the engine and it was suggested to do a decarb. I still haven't gotten around to doing it but I did notice it not smoking near as much as it used to. I recently checked the compression and the higher side came down closer to the others and seems more in a normal range. I'd do a decarb. I think mine was burning off a lot of crud in the engine from sitting up. I had run the engine for several hours before I noticed the smoke wasn't as bad.

Make sure the red manual lever on the choke solenoid is pointing straight down (inline with the body). I doubt that yours is set wrong because it would flood really bad, but it's worth a check.

 

[emdsapmgr]

Re: 1985 johnson 140hp V4

A few things to check. Run the engine without the airbox cover and see if any excess fuel is coming out of the front of the carbs and running down the inside of the airbox. It's not unusual for a little to dribble out of the carbs when the engine is shut off and tilted upward (for fishing.) The airbox itself has a drain at the bottom which is connected by a hose (at the back) to the bottom crankcase cylinder. This hose sucks (recirculates) exess fuel back into the bottom cylinder for combustion. When any exess fuel accumulates in the airbox, it will cause smoking (loading up) due to excess fuel being sucked into the bottom cyl. Usually this will clear out after 30 seconds. If the drain in the airbox is plugged, excess fuel could accumulate in the airbox itself. After you complete your testing, you should always run with the airbox cover installed.

 

[sred137]

Re: 1985 johnson 140hp V4

Thanks again for the replies.Sorry for the delay in getting back to you.I ran the boat thanksgiving morning and it was not a good test as I could not get up on plane due to really rough conditions.

The boat seamed to start a lot better and ran smoother at idle(did not cough and sputter) but still wanted to idle slow and stall.

I did not know of a drain at the bottom of the air box before.I will investigate that to see if it is possibly plugged.

Now tal when you say decarb,do you mean running a carb cleaner through the motor.Something like seafoam.I've been recommended seafoam from a friend but have yet to try it.


Really appreciate all the replies
Shawn

 

[Tacklewasher]

Re: 1985 johnson 140hp V4

Decarb instructions

http://forums.iboats.com/showthread.php?t=302825

Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

 

[sred137]

Re: 1985 johnson 140hp V4

This may be a stupid question but I have a VRO pump and I do not premix my fuel.Is it ok to just put the 3/4 can of seafoam into a gallon of gas and run the motor same as I normally would?I shouldn't have to double up on the oil going into the motor should I?

Thanks Shawn