Johnson 1985 140 won't rev

[GTJim]

I have a 1971 19? Robalo center console with a 1985 Johnson 140 hp engine.

It was hard to start and would run ok for a while and then sputter and sometimes just quit. It would, some days, plane out just fine at 4200 rpm.

After reading the forums here and talking to a couple of friends, I decided that I had a bad bulb and possibly bad fuel line plus old fuel or water in the onboard tank.

I hooked up a new fuel line with bulb along with a 6 gallon tank of non-ethanol fuel. It cranked quicker and idled fine after a short while. It ran quite smoothly at low speed but will not rev up and plane out. I read about a ?slow mode? and wonder if I am stuck in that or perhaps have a choke problem.

There is a long wire that is not attached(see picture). I bought the SELOC manual and have picked up a lot from that but it does not help me identify specific parts wires etc for my engine so I don't know where it goes.

Suggestions?

 

[Bob_VT]

Re: Johnson 1985 140 won't rev

You found the right place.

Okay there could be multiple issues going on right now. Is the boat/motor new to you? How old is the problem?
V-4's are great motors! They do require a small amount of TLC and run great.
Here are a few questions:
The impellar should be done yearly or at least every 2 years (Plus thermostats and water deflectors at least at 5 years)
The carbs should be removed and rebuilt at least every 3 years to keep all the passages clean and working at their peak.
Depending on the compression and use of the motor I believe in a de-carbonization at least yearly to keep the rings clean and the compression up.

Seloc manuals do not hold a candle to the real thing ...... real manuals available here www.outboardbooks.com and worth every penny!

What you describe sounds like a lost cylinder (not firing) You really do not have a choke but an enrichment system that just squirts extra fuel into the carbs.

You are going to need to do some troubleshooting since your motor should be turning 5500 rpms at WOT (wide open throttle).

I would check the compression in each cylinder. (compression gauge) Among the 4 you should be within 10% of each other. When you remove the plugs look inside the hole and see it any of the pistons are real cleanas compared to the others (which could indicate a head gasket leak allowing water in)

I would check the spark on every cylinder. (Timing light)

Get back with the results here. When you get the results hit the POST A REPLY button.

oh yeah...... without seeing the whole thing I have no idea whgat the wire is but there are sensors on the head for overheating.

One other thing since you are new. You may have to scroll a few pages to find your thread since this is a very active section of the forum.

 

[GTJim]

Re: Johnson 1985 140 won't rev

I have had the boat for about 10 years. It developed this problem a few years back. I have had two mechanics work on it doing the regular things: water pump, carb rebuild, compression check, spark test etc. I?ll have to check on the thermostats.

I will order the real manual as advised.

Before I changed the fuel line/bulb/fuel, the engine would rev up over 5,000 rpm(that is when it would run). I just wondered if I nudged something loose when I took off the engine cover and thought that wire would have to be connected to get it out of ?slow? mode.

Below are two more pictures of the wire. Is it possible to show me where it might attach?

Thanks for the help.

 

[krimi]

Re: Johnson 1985 140 won't rev

Does it rev up in neutral? And then bog out and not plane in gear..3000 rpm or so??...high speed jets. A good carb job is acid washing.

 

[GTJim]

Re: Johnson 1985 140 won't rev

Does it rev up in neutral? And then bog out and not plane in gear..3000 rpm or so??...high speed jets. A good carb job is acid washing.

I think it revs OK in neutral but I will fire it up and make sure. It is not so much that it bogs down but more throttle just does not get any higher revs. It runs smoothly but seems rev limited.