1975 Johnson: Fuel in Exhaust

[jgough]

Hi all, I have a 1975 Johnson 115 V4. It was running great, then wouldn't start, with a ton of fuel coming out of the exhaust, and black goo dripping out after I brought the boat out of the water.....Now it still won't start, and more fuel is coming out...is the carb float stuck or something? Please help!!
Thanks in advance!!

 

[mikesea]

Re: 1975 Johnson: Fuel in Exhaust

you have 2 carbs,you do seem to have a major flooding problem,your engine ,if Im right dont have VRO meaning you mix the gas,Id bet the fuel pump blew a diaphram and the fuel is pouring into the crankcase through the pulse line ,which is the hose that comes off the crankcase giving the pulse that operates the fuel pump,

 

[Chinewalker]

Re: 1975 Johnson: Fuel in Exhaust

Or, you may have lost spark, in which case the fuel is just running through the motor when trying to start it up... Check for spark - but in a well ventilated area. You don't want all that fuel to flame out on you!
- Scott

 

[tashasdaddy]

Re: 1975 Johnson: Fuel in Exhaust

was the engine tilted when trying to start, the floats don't always seat the needle do to the angle. i agree, either the fuel pump or float needles. have you check spark and compression?

 

[jgough]

Re: 1975 Johnson: Fuel in Exhaust

Thanks for the replies!

I did check for spark on 1 plug wire, and the spark jumped the gap from a screwdriver to the block in daylight, so I think it's ok....

The motor was not tilted when I tried to start it, it was in regular running position.

The "super-rich" condition started right after I had run the motor in full throttle for a few minutes ( I was checking the speed with a GPS). I shut off the motor, went and got the truck, and when I tried to start to get it on the trailer, it wouldn't start and a ton of gas came floating up... so it went from running to not running in 2 minutes...

Should I try replacing the fuel pump first? THANKS! -Jim

 

[DJ]

Re: 1975 Johnson: Fuel in Exhaust

No oil injection on that engine.

It could be carb needle/seats.

It could also be a failed diaghram in the fuel pump. Been seeing a lot of that with more ethanol showing up in the fuels.

 

[wavrider]

Re: 1975 Johnson: Fuel in Exhaust

Definately look at the fuel pump, also and maybe this is not important as I am not an expert but try pumping your primer bulb to see if it gets hard and holds pressure. If the primer bulb does not get hard it is the sure sign of fuel leakage problem either in the lines,pump, or carbs.
You can eliminate the carbs one at a time by disconnecting them at the T where they are connected at coming out of the fuel pump. Just disconnect the fuel line and install a piece of capped off fuel line to isolate a single carb, pump the primer bulb to se if it gets hard and stays firm.
If it does turn out to be a carb at least you have isolated which one it is and can gofrom there.
If it does turn out to be a carb I would reccomend to rebuild both of them since you are tearing into it.
If it turns out to be a pump rebuild kits are available also.
I have a 1978 115 so a little familier with what you are doing, please feel free to ask any questions, enjoy n be safe,WAV.

 

[jgough]

Re: 1975 Johnson: Fuel in Exhaust

WOW, outstanding tips and info...thans yo guys so much. I will let you know what I find out. I feel like I have a real direction to start looking in, thanks to you all.
Jim

 

[jay_merrill]

Re: 1975 Johnson: Fuel in Exhaust

You might also want to check all four spark plug leads for spark. I bought a very handy little spark checker at Autozone the other day - it has a spark plug type insert for the lead/boot and an adjustable screw/ground clip so that you can set the gap as recommended for your motor. The grounding clip is too short to work easily on an outboard so I just clipped a piece of wire in that and ran it to a ground.

Mine is checked with a 1/2" gap and the test that I ran showed nice, fat sparks when I used it. Just bear in mind that these things only check what is happening when you do the test, so if you have an intermittant coil or something, they don't always pick that up.

 

[HighTrim]

Re: 1975 Johnson: Fuel in Exhaust

I use to use the same one Jay...



until I got a multi cylinder spark tester, they are much handier, especially if you have a 2 cylinder + outboard. It tests the spark simultaneously on all cylinders.

 

[Gary H NC]

Re: 1975 Johnson: Fuel in Exhaust

Same one i use too.I thought it was a cheapo but hey it works good!

 

[jay_merrill]

Re: 1975 Johnson: Fuel in Exhaust

Yup, the first one is exactly what I bought. Where did you get the multi-cylinder unit?

 

[HighTrim]

Re: 1975 Johnson: Fuel in Exhaust

Ebay

"http://cgi.ebay.com/ebaymotors/Marine-Spark-Gap-Tester-Adjustable_W0QQcmdZViewItemQQ_trksidZp1638Q2em118QQcategoryZ50442QQihZ013QQitemZ230205572426QQrdZ1QQsspagenameZWD1V"

They are also handy since you can visually see the difference in spark between cylinders. Hard to see that testing them one at a time.

 

[jgough]

Re: 1975 Johnson: Fuel in Exhaust

OK very good, very good....now where to start...I think I'll check the spark in each cyl., as mentioned, then check the fuel pump....trying to go from easiest to most difficult....thanks guys, I wish it were warmer in the garage!!
Jim

 

[iwombat]

Re: 1975 Johnson: Fuel in Exhaust

ooooh garage . . . fancy.

Out here in North Bend we just call it a car hole.



(Gig Harbor native)

 

[thresher15]

Re: 1975 Johnson: Fuel in Exhaust

FWIW I had a bad stator on a '96 carbed johnson 175 that allowed the motor to run on 3 of the 6 cylinders. No spark on the other 3 cylinders and fuel was dumping out of the exhaust.

 

[jgough]

Re: 1975 Johnson: Fuel in Exhaust

good tip, thanks, I think I'll check the spark in all cyl's