Johnson staring problem

[regf]

Hello
I have a 1995 Johnson 50hp that hasn't done much work but I continue to have starting problems with it for the past 6 months that I've owned it (since I've owned it). Cranks over with ease but has intermitten problem with firing .......... Done all the diagnostics tests out of the manual in relation to stop buttons, coils and checked all wiring harness....all appears OK. Seems to work fine when eventually started (can take upto 2 hours to get started)but leave it sit for 2-3 days, ***** to start again. Spent much $$$$ on marine mechanics trying to fix intermitten problem without success. I believe it is firing on one cyclinder??...is this suppose to happen??...should I replace coil or resistor??? any other suggestions???
Thanks, Reg

 

[tashasdaddy]

Re: Johnson staring problem

Welcome to iboats. what exactly, step by step,are your starting procedures. this is usually human error. have you confirmed it is firing on only one cylinder, believing is not a diagnostic term. what's you compression.

diagnosis before throwing parts and money at it.

 

[HighTrim]

Re: Johnson staring problem

http://forums.iboats.com/showthread.php?t=225510

 

[regf]

Re: Johnson staring problem

Thanks for the instructions..........is very similar to the process I have been following. Only variance is the note about pumping the fuel bulb until hard, I find if I do this it floods the engine so much oil drips out the exhaust? I tend to only give the bulb 2 pumps and this generally is sufficent fuel at the carby (have checked this). Thanks for the info as it gives me reassurance that I'm on the right track for the starting process.......

 

[regf]

Re: Johnson staring problem

Process I normal follow for starting is;
1) Slight tilt of engine to ensure water pump can pump water
2) 2 x pumps of the fuel primer bulb
3) Check it is in neutral and pull choke half way up
4) Turn key and push to inject additional fuel if required

It runs on both cyclibnders just when starting it only fires on the bottom cyclinder.......is this normal? I have swapped spark plugs and leads to eliminate these being the issue why it isn't firing (at start up) at the top cylinder. Haven't checked the compression personally but once its started it runs very well which leads me to believe that engine compression is OK, besides 2 x marine mechaincs have done this test and state ALL OKAY!

When storing the unit between trips out to the bay (average 2-3 weeks storage) should I run the motor out of fuel when flushing out or just turn off thus leaving fuel in carby?! Thanks Champ!

 

[HighTrim]

Re: Johnson staring problem

Never run the motor dry on a multi carb outboard, leaves the top carb running without oil, and that is not good. Mix Stabil or Seafoam with your fuel instead.

 

[tashasdaddy]

Re: Johnson staring problem

move engine all the way down, tilted cause the carbs to overflow, the lever you lift is the fast idle lever, not the choke. the motor does not have a choke. move the lever all the way up, then when started lower to slow idle speed. pushing the key activates the enricher solenoid that injects extra fuel into the intake, ( sort of acts like a choke). use a fuel stabilizer, in your fuel, and never run the carbs dry.

 

[ezeke]

Re: Johnson staring problem

You say:​

"Process I normal follow for starting is;
1) Slight tilt of engine to ensure water pump can pump water
2) 2 x pumps of the fuel primer bulb
3) Check it is in neutral and pull choke half way up
4) Turn key and push to inject additional fuel if required"
​

Try it this way:
1. Engine in running position, or Anti-ventilation plate parallel to water;
2. Pump the primer bulb until it is firm;
3. Warm up lever up;
4. Push the key in while cranking until it fires, then let the key out;
5. If the engine hesitates, bump the key in a few times.​

 

[flabum]

Re: Johnson staring problem

Only variance is the note about pumping the fuel bulb until hard, I find if I do this it floods the engine so much oil drips out the exhaust? ..

Sounds like a float is sticking open. If it still does that with the engine level, you need to remove the carbs and check the needle and seats.

 

[itstippy]

Re: Johnson staring problem

"It runs on both cyclibnders just when starting it only fires on the bottom cyclinder.......is this normal? I have swapped spark plugs and leads to eliminate these being the issue why it isn't firing (at start up) at the top cylinder. "

I'm not sure what you mean by this. Do you have spark at the top cylinder when you use the starter? If you have no spark or weak spark on the top cylinder when you use the starter then you must find the cause. There should not be a difference in spark quality between cylinders when cranking with the starter.

 

[bagnallt]

Re: Johnson staring problem

Hi all.. I had this problem a while back. The motor a 50 hp was only firing on the top cylinder. In my case it was the idle needle on the bottom cylinder that had turned itself all the way in. I adjusted it out by 1 and 3/4 truns and bingo the cylinder fires as it should. Take a look at it becasue the rubber holders which restict the needles from turning rot out and allow the needle to turn as the engine vibrates. I fixed it and it ran well.. Until I sheared the Flywheel key. Which thanks to guys here ( Tashasdaddy to name but one ) Its all fixed now and i am off fishing tomorrow...