1975 Johnson 25hp 25RL75B Not Starting

[87fourwinns]

I've been browsing the forums for a while but now I'm here for some help...

Here's the story:

I bought this motor last week and got for $60.00. When I picked it up, it was filthy and had been sitting for a few years. It had good compression (approximately 118 psi in both cylinders) but no spark. The night I brought it home, I tore it down and sanded the points. Boom! We had spark. Being excited and not having a gas tank on hand, I gave it a shot of starting fluid and she fired up for a second (I'm aware this isn't a great idea but I was caught up in the moment). One of the ignition coils was cracked so I replaced both and replaced both spark plugs.

I got my hands on a gas tank and hooked it up with high hopes. However, it wouldn't start up. Wouldn't even kick over like it wanted to start. I pulled the plugs and still have good spark and they were both wet and smelled like gas. There was actually fuel dripping from the exhaust and the throat of the carb.

I purchased a rebuild kit and plan on digging into that job tonight. Is there anything glaring that I should be looking for? I don't have any experience with working on outboards so I'm flying by the seat of my pants and basically relying on these forums and youtube videos to get through.

I'd appreciate any input if someone has had a similar experience...

Thanks!

 

[Bosunsmate]

Re: 1975 Johnson 25hp 25RL75B Not Starting

hi
light the fuel on the plugs to check its fuel not fuel mixed with water.

If thats ok and you are sure the spark is jumping a 7/6 gap then you will need to check timing, maybe the coils are hooked up to the wrong cylinder, or its out of time somehow

 

[87fourwinns]

Re: 1975 Johnson 25hp 25RL75B Not Starting

Thanks for the reply. Seeing as I'm no expert... how would I go about checking timing? Sorry if the answer is obvious haha

 

[Bosunsmate]

Re: 1975 Johnson 25hp 25RL75B Not Starting

I wish it was obvious, takes bit of explaining
But you need a timing light $15 or so to start with.
You then hold the light over the flywheel and attach a lead to the sparkplug lead and see where the light lights up on the flywheel.

Theres a few youtube videos on it

If it starts on that engine starter stuff, use a spray bottle and put in some two stroke mix.
If it runs on that, your timings probably ok
Are you sure the spark jumps a good gap?

 

[Bosunsmate]

Re: 1975 Johnson 25hp 25RL75B Not Starting

Also the motor in that test is running real weird so it shouldnt look like that on a proper running engine. Also the flywheel will be marked on yours so you dont need to add paint to it

 

[Bosunsmate]

Re: 1975 Johnson 25hp 25RL75B Not Starting

Plugs cant be wet with fuel and have good spark unless you are flooding it or spark isnt good.
Check choke isnt stuck on and check primer bulb is hiolding firm with engine off.
If it isnt itcould mean you a getting a leak into the engine and its flooding out

 

[87fourwinns]

Re: 1975 Johnson 25hp 25RL75B Not Starting

Thanks! I'm heading home to work on it now. Hopefully your guidance can get me on the right track. I guess I'll try to pick up a spark tester on the way home.

Also, Yes it does start with a shot of starter fluid so I believe the timing isn't the culprit. I'll try the spray bottle technique. I'm guessing it should work the same as the starting fluid.

 

[Bosunsmate]

Re: 1975 Johnson 25hp 25RL75B Not Starting

Thanks! I'm heading home to work on it now. Hopefully your guidance can get me on the right track. I guess I'll try to pick up a spark tester on the way home.

Also, Yes it does start with a shot of starter fluid so I believe the timing isn't the culprit. I'll try the spray bottle technique. I'm guessing it should work the same as the starting fluid.

Yes it might unless the engine is flooding.
Starter fluid is just a bit stronger so it can temporarily fire a flooding engine.
Check primer bulb holds firms first with engine off,
Fuel on plugs and out of carb throats sounds far too much.

Lucky you, Im soon heading off to work myself in this southern timezone

 

[JohnnyRudeClassics]

Re: 1975 Johnson 25hp 25RL75B Not Starting

too much fuel could mean the float / inlet needle is stuck open
you will likely trap it out when you rebuild the carb

 

[87fourwinns]

Re: 1975 Johnson 25hp 25RL75B Not Starting

Well after some blood sweat and tears.... She purrs like a kitten!

I tore the carb apart and the tip of the inlet needle was completely missing. Also, there were quite a few parts that were just plain missing from the carb. I'm guessing someone attempted to get it running but gave up. After rebuilding the carb, it started up on the second pull and ran real strong. Took it out on the river yesterday afternoon and I was more than pleased with how it ran.

Its a long shaft motor on a short transom so it wasn't optimal. But I'm going to rig up some kind of jackplate to get it sitting where it should.

Thanks for your help! Gotta love the guys at iboats

 

[loiner1965]

Re: 1975 Johnson 25hp 25RL75B Not Starting

glad its sorted