Stalling Motor?

[Maximum12]

My reliable '67 9.5HP Johnson is having a rough summer.

At the moment, the nasty little beast is sometimes starting, sometimes not. Once I remove the hood, the think fires up on the first pull every time. It seems like it's not getting any air under the hood.

Any speculation as to what's causing this?

[Chris Haley]

I would be looking more for a short than airflow. Does it fire at all with the hood on when it doesn't start?? Even with restricted airflow it should at least fire. Nothing with the hood and starting as soon as you take it off sounds like an electrical short.

[Valv]

I agree with Chris, also check hood when it closes, it might catch a coil or plug boot and short it out.

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Val Vignati

www.kvesurplus.com
sales@kvesurplus.com

[Maximum12]

Sorry I wasn't specific enough!

The motor will run sometimes with the hood on, & always fires, but when it starts, it stutters & barely idles until I put it into gear. But if it dies, it'll start for a second or two, cough, & die on me. This will happen as many times as I want to pull the cord until I take the hood off.

[IFallsRon]

Does it run OK with the hood off?

[Surface Tension]

Should be getting plenty of air with the cover one. Did you look to see if the cover latch is snagging or grounding a plug wire when you replace the hood. Also look for loose wires routed under the flywheel that may be getting grounded out. Look for loose sound proofing(insulation)on the cover obstructing movement on the timing advance.

[Maximum12]

It runs perfectly with the hood off.

Thanks all. I'll check to see if anything on the hood is loose or messing up the works. Hopefully a few minutes will solve the problem in the next day or two.

[fishermn]

I had exactly the same problem with a '74 Johnson 15 HP. Same exact symptoms, and it was just as the others suggested. It turned out that one of the plug wires was arcing over to the hood, and shorting out the plug. Hard to belive I know, but I found out for sure when I got my hand too close to the plug wire when it was running... Now that was an arm numbing experience I will tell ya! In the case of that particular unit, I had to buy an entire coil assembly because the plug wire was molded right into the coil assembly. It didnt turn out to be all that expensive, but it made a world of difference. Like you I was initially thinking it was an air intake problem, but that wasnt the case, and the new coil+wire did the trick. Good Luck!

[fishermn]

One other comment: I could not actually see any damage on the spark plug wire on mine. Although when you got something close enough to the plug wire, it would arc over. The puncture in the wire must have been pretty small.