1978 Johnson 115 idle problems

[Cloverdale77]

1978 Johnson 115 with all kinds of problems. It is hard to start, hard to idle, hard to accelerate. It takes feathering the throttle a lot and restarting to both idle, idle in gear, and accelerate in gear while in water. Once it does manage to accelerate in gear it will wind out to WOT and scream across the lake. The low speeds is when it has problems. Out of the water, it will start, idle and idle in gear no problems. I synchronized the engine per the Seloc manual. I cleaned both carbs and removed the jets and found no varnish or dirt. I set the floats as best I could from the manual and suggestions on here. I found that the OMC QD fittings on the supply side fuel lines were junk and new fittings leaked air within an hour of use. I just went with a hose barb for the time being until I can find a replacement QD that is not going to leak. I found that the spark advance at idle out of water was 0 degrees. The book recommends 0-4 degrees. The plugs all look good but were gapped at 0.030". I widened that to 0.040". Nice blue spark at all plugs. I have a spark checker and DVA on order to get more accurate spark readings as well as ignition system readings. Compression test was 115, 114, 120, 122. The lower being the starboard bank. Higher port. If the engine is trimmed anything but all the way in, it sputters at idle and dies easily. I found that if I pull the spark advance lever and accelerate the engine, everything is fine. If I use the quadrant to accelerate, the spark advance lever lags behind the throttle a lot before it starts to move and this is when the engine likes to die. How far should the throttle lever move before it moves the spark advance? This is frustrating as everything works out of water and putting the boat in water means I have no way to check timing and loosing tools becomes an issue. Once the spark check shows up I will be able to see if the 7/16" gap still provides optimum spark and I will see if the charge coils produce good voltage. Any other suggestions would be greatly appreciated.
Thanks in advance.

 

[boobie]

Re: 1978 Johnson 115 idle problems

It sounds like your timer base is sticking due to old grease getting hard that was put on it sometime ago.

 

[emdsapmgr]

Re: 1978 Johnson 115 idle problems

Boobie has a very good comment-worthy of checking. The plugs on that engine are supposed to be gapped at .030. It is not unusual for compression to vary slightly from one head to the next, depending on how the block was originally bored at the factory. Your compression is ok. Don't fret about the idle timing degrees. Set the idle based on the idle rpm's-set the idle to 650-750 when the boat is floating in the water, and it's in forward gear. The control box will move the shift linkage to engage either forward or reverse gear before the throttle starts to move the linkage on the side of the carbs. Sounds like you are very familiar with working on this engine. As such, I'd pitch that old Seloc and get an original factory manual from Ken Cook Co., in Milwaukee. That's the only one to have. That manual has an excellent section on the sinc and link procedure. Use an inductive timing light to check the spark on each plug wire when you have the engine under load: check the spark when it's idling in gear at the dock. The engine loading situation is a lot different when the exhaust is 20" under water than when it's idling on the trailer.

 

[mrcj001]

Re: 1978 Johnson 115 idle problems

I found that if I pull the spark advance lever and accelerate the engine, everything is fine. If I use the quadrant to accelerate, the spark advance lever lags behind the throttle a lot before it starts to move and this is when the engine likes to die. How far should the throttle lever move before it moves the spark advance?

I dont think the engine is snync`ed right...........

 

[Cloverdale77]

Re: 1978 Johnson 115 idle problems

This is my dad's boat though I have done some outboard work before. Never this involved in troubleshooting though. I don't think the linkage is working as it should. The timer base moves freely, but the advance lever lags a great deal behind the throttle lever on the engine. I think the advnace lever and throttle lever should move together until the advance lever meets max advance stop. If I do this myself not using the control quadrant, then there is no hesitation or diing under load. I have used the timing light to check for pulse while on the water at idle and under load. Problem is that it doesn't take much to trigger the light. So even if it is a weak signal, it will still fire the light.
It seems like the throttle/spark advance levers are sticky. Like the grease on them is causing the advance lever to lag. Maybe the spring is weak. I just haven't found anything on here or the manual to tell me that these two levers are suppose to move together until max spark advance.
I took the fuel pump apart just because we had a rebuild kit and might as well. I found that fuel poured out of the pump on the engine pressure/vacuum port. I thought the diaphragm was suppose to keep fuel out of the engine at this point. It was a sucker to put back together, but I think that may have contributed to some rough running.
I plan on checking spark with a real spark checker tomorrow. If no fault found, I will focus on the levers to see that they move together. Then back to the lake to see what happens. We've had so much water here lately that I have to launch from the road. The ramp is a couple hundred yards in the lake and under 20' of water.
There are a lot of different hits for Ken Cook Company in Milwaukee. Do you have a phone number, website, email address? I don't care much for Seloc....

 

[TLL]

Re: 1978 Johnson 115 idle problems

The spark advance lever and the throttle lever should move at the same time until the spark is at maximum advance, you are correct. I would also suspect the piston rings are sticking a little. Buy a can of BRP engine tuner, warm the engine up, while running the engine spray the contents of the can through the carb venturis (blip the throttle to keep engine from dying). Let motor sit overnight, start motor and run under a load up to max rpm for several minnutes to burn out the engine tuner. This process might free up some sticking rings and improve idle quality and overall runability. For a factory manual Ken Cooks website is www.outboardbooks.com

 

[emdsapmgr]

Re: 1978 Johnson 115 idle problems

It's not unusual for the factory grease under the timer base to dry out with age and slow the movement of the timer base. If that is what you think is happening, you should remove the flywheel and the timer base and clean/replace the grease with some fresh white lithium grease. Ken Cook Co.'s phone is: 414-466-6060.

 

[Cloverdale77]

Re: 1978 Johnson 115 idle problems

I appreciate the manual reference. I have one on the way.
I found the timer base was sticking, so I re greased it. It is still not real slippery and the spring on the lever doesn't seem strong enough to overcome the viscosity. I used lithium grease on it. Granted, the temperature is in the 30s-40s. I am not able to adjust the spring tension on the levers. So I think I will order a new one.
With spark checker adjusted to 7/16", I have no spark on one bank. Using spark plugs, I do. The resistance measurements didn't come close to the Seloc recommendations for the charge/sense coils, but they were the same on both sides and I have good spark on the other bank. I had lights off in the garage and made sure there was no leakage. The coils at the plugs measure the same on both sides as well, so I am leaning towards a power pack. I had one replaced a couple years ago and it is the same side that isn't sparking this time.
I appreciate all your responses. It certainly helps.

 

[emdsapmgr]

Re: 1978 Johnson 115 idle problems

The coils on that engine have a fairly low failure rate, compared to the power pack. Fortunately, with this engine, you have an opportunity to do some electrical troubleshooting on your own. That engine has two idential power packs. Swap them. If the "no spark" issue moves to the other head, You probably have a bad power pack. Also, run the engine in dim light and make sure neither of the bottom two spark plug wires are grounding out on the lower cowling latches. A rarely considered possibility.

 

[mkay]

Re: 1978 Johnson 115 idle problems

Evinrude uses a low output alternator on these engines. If the engine is run at less than 2000 RPM for extended periods the battery will run down due to starts and restarts which take a lot of battery power.That is why they didn't put a charge meter on these rigs. If you have a volt meter on the boat check the battery voltage as you crank the engine. If it falls below 10 to 10.5 volts when cranking the ignition system will not fire reliably and starting will be a problem. Lots of starting motors have been sacrificed for this design cheapy. It also will not idle well, although once you get the RPM above 2000 the alternator will run the system and the engine will take off as if there is no problem. If you have a voltmeter you will see the voltage rise to 13.5 to 14.5 volts which means the battery is charging. These motors were not designed for trolling. It's a good idea on these engines to have a fresh good quality battery and don't run them at low RPM for extended periods. Maybe that is why bass fishermen take off at high speed regularly although that must scare the fish. Some people call this a low voltage problem. I call it one of the many problems that eventually killed Evinrude. An inexpensive solar cell charger is a pretty good idea. It will do the job while you sleep, but do not get a sealed battery since you will need to add water from time to time.