1974 Johnson 9.9 Won't start

[Putzaroni1]

I was finally able to start working on this motor and it would not start.
I began by removing the carb and spraying it out with carb cleaner and compressed air. There was rust on the outside of the float bowl but none on the inside. The float was a cork one and was a black color but was hard and not soaked with fuel so I left it in (at least for now). I cleaned everything without pulling the core or welch plugs (whatever they're called). The carb was fairly clean and did not have build up inside. The plugs looked pretty good but I replaced the Champions with NGK B7HS plugs and put an inline spark tester on both cylinders. This is a pretty bright blue spark from both.
I replaced both of the fuel lines plugged into the fuel pump, one from the fitting to the pump and the smaller one from the pump to the carb. I also unscrewed and looked at the fuel pump. The screen was clean and I could blow through the pump with my mouth. I hooked it up and disconnected the fuel line at the carb. It trickles out of the pump but doesn't seem like enough fuel. I put a fuel system pressure tester on it and get about 2 PSI when I pull start the motor with the tester connected. When I pump the priming bulb I get 8 psi.
I also did a compression test and am not sure what it should be but both cylinders are between 85 and 90 psi.
It does not sputter or make anything that would encourage me that it is trying to start.

I'm lost now. I am about to pull the carb off again check it but thought maybe someone can provide some guidance here.
I've ready through a bunch of previous posts and Leroy's Ramblings but not knowing how much pressure the fuel pump should have or what the compression should be, I'm kinda floundering.....

Thanks for any suggestions.

 

[Bosunsmate]

Re: 1974 Johnson 9.9 Won't start

Ground the spark cover boots but leave the sparkplugs in and then pull the starter a few times. check they a both wet with fuel.
if they are then check the timing

 

[Putzaroni1]

Re: 1974 Johnson 9.9 Won't start

I'm assuming I would just pull the 2 leads off and insure they are touching the engine block ? If so I'll try that tonight.
I have not yet pulled the ignition apart and that will be new to me but it's all a matter of learning.
Thank you !

 

[Fleetwin]

Re: 1974 Johnson 9.9 Won't start

You need three things to make it run:

1. Compression. You have that.
2. Correct fuel/air mixture. I doubt that. You need to more thoroughly clean the carb. (removing plugs). And, replace that cork float.
3. Spark, at the right time. You MAY have that. I would pull the flywheel to make sure the flywheel key has not sheared.

 

[Joe Reeves]

Re: 1974 Johnson 9.9 Won't start

Compression is good.

Check the spark by removing both spark plugs, then rig up a tester whereas you can set a 3/8" gap for the spark to jump. The spark should be a strong blue lightning like flame... a real SNAP! Is it? The gap is important!

Spark Plugs should be Champion UL81J gaped at .030 .

The brass object at the bottom nozzle of the carburetor top body is a high speed jet which must be absolutley clean (sits at the bottom portion of the float chamber). Fuel must flow thru that jet before it can gain access to any other passageway of the carburetor. Make sure that it is clean.


(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

If you have fuel, compression, and ignition, the engine has to fire in some fashion. Let us know what you find.

 

[Bosunsmate]

Re: 1974 Johnson 9.9 Won't start

I'm assuming I would just pull the 2 leads off and insure they are touching the engine block ? If so I'll try that tonight.

yep thats it, if one or both plugs a not wet with fuel then fuel delivery is your problem (at least)

 

[Putzaroni1]

Re: 1974 Johnson 9.9 Won't start

Looks like fuel delivery is likely the issue. I pulled the carb and cleaned I again with everything EXCEPT the plugs. I put it back together, primed it up, pulled 6 or 7 times with the choke out and then again 6 or 7 with the choke off and nothing. I then pulled the plugs and they look like new. Doesn't look like any fuel got to them. I will do the complete carb rebuild including the core plugs and then try again.
So do I need to soak this in solvent if it's not too bad once everything is apart or just hit it with carb cleaner thoroughly and then blow everything out with compressed air ? Also, it's an OEM kit from OMC. Do I replace everything or just the items that look like they need replacing ? Thanks again......

 

[racerone]

Re: 1974 Johnson 9.9 Won't start

Is the choke plate fully closed when you pull out the knob ??

 

[OptsyEagle]

Re: 1974 Johnson 9.9 Won't start

I would squirt some premix gas into the carb throat and give the starter cord a pull and see what happens and then I would remove each spark plug and put a teaspoon of premix in the cylinder's and try it again. See if you can get it to pop a little that way.

 

[AlTn]

Re: 1974 Johnson 9.9 Won't start

fuel pump pressure from 1978 9.9/15 hp. FM...600 rpm=1 psi...2,500 to 3,000 rpm=1.5 psi...4,500 rpm=2.5 psi : you can always rig up a gravity feed to the carb to take the f/p out of the equation as far as a starting problem cause < make sure to divert the fuel from the pump to a container as >...I'm with Optsy on the starting deal; you should get at least a sputter using his suggestions

 

[racerone]

Re: 1974 Johnson 9.9 Won't start

When you operate the manual fuel pump then the carburetor fills with fuel.-----Fuel pump starts doing it's job once motor starts.---Fuel pump does not come into play during the starting !

 

[Putzaroni1]

Re: 1974 Johnson 9.9 Won't start

I'm embarrassed to ask this one but what is the best way to squirt premixed fuel into the carb ?
I could get some in there but is there a good easy way ?
Laughing at me is allowed for this question !!

 

[bonzoscott]

Re: 1974 Johnson 9.9 Won't start

Squirt bottle. I use an old Armor all bottle. It holds up to fuel.

 

[AlTn]

Re: 1974 Johnson 9.9 Won't start

with new plugs it isn't always apparent that they are soaked with fuel...I hold the plug in one hand and try to sling any fuel mix off onto the palm of the other hand...none should come off unless the plug is soaked

 

[racerone]

Re: 1974 Johnson 9.9 Won't start

I see no reply on the actual gap that the ignition can fire.---------So will spark jump a gap of 1/4" or more?-------Laying plugs on the block is not a very good spark check !

 

[oldboat1]

Re: 1974 Johnson 9.9 Won't start

think racerone correctly wants to point back to plugs. As Joe Reeves pointed out, the standard gap for the Champions is .030. I would go back to the original Champions (the ones you removed), if they were the right plugs for the engine, clean them with 400 grit sandpaper or similar, and maybe a little carb cleaner or lacquer thinner, regap and reinstall them. Try it with the original plugs and see if you get the engine to pop. I don't know if the replacement plugs you installed are exact replacements for the correct Champion plug (go with the one Joe R. cited). You don't want to change heat ranges, for example, until you have the engine running and want to make a correction or set it up for a particular application.

 

[AlTn]

Re: 1974 Johnson 9.9 Won't start

a little late in the game, but what is your starting procedure?...do you twist the throttle as far as it will go in neutral,pull the choke on, then use the pull start?...with the throttle advanced in neutral is the carb linkage roller slightly past the mark on the timing cam and the throttle plate open slightly?..speaking of choke, choke pull specifically, is the long slot facing up or down?

 

[racerone]

Re: 1974 Johnson 9.9 Won't start

Post # 8 asks a question about the choke , but no response on that ???

 

[PutPut1]

Re: 1974 Johnson 9.9 Won't start

I have the same motor and same problem. I squirt a bit of fuel (an eye dropper works) into the cylinder and it goes on the first pull. It will keep starting as long as I don't let it sit too long. (More than a few days). That should hopefully get you started. I asked a question today about how to correct it all together.

 

[Putzaroni1]

Re: 1974 Johnson 9.9 Won't start

Thank you all for your suggestions. I have been working a ton and didn't get a chance to get on here for the last week. I will dig in tomorrow afternoon and try your suggestions and report back....... Thank you all for your ideas..... This one is a good learning motor for me. More to come tomorrow.