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Runs great, won't start 1987 40hp

CJ51973

New member
I have rebuilt the carbs, new plugs and swapped the leaky VRO for a standard fuel pump on my 87 Johnson 40. It now runs great but it takes for ever to start. It will crank & crank, finally start sputtering a little and then run. You can turn it off and it will fire back up first crank. Idles good, shifts in and out fo gear without dieing. The plugs are wet during this cranking so it's getting fuel it would seem. So I am assuming spark? But it doesn't make a lot of sense because it runs smooth once it starts. Ideas? I haven't been around this motor long but it never started that well.
 
Re: Runs great, won't start

Try a new 6 gallon fuel can, with new fuel line and bulb assembly and see if the problem goes away. Sounds like a fuel issue to me.
 
Re: Runs great, won't start

I have two tanks. Does it on both. I guess both could be bad. It's getting a strong spurt from the primer solenoid.
 
Re: Runs great, won't start

Is this only a cold start problem, or when first started after sitting for a long peroid of time?
Could the needle and seat be leaking fuel when sitting and flooding on start up?
Do you leave your fuel hose connected when not in use?
 
Re: Runs great, won't start

Is this only a cold start problem, or when first started after sitting for a long peroid of time? It will do this if it hasn't been started for an hour or longer. I haven't tried a shorter restart other than maybe 2-3 minutes. Then it starts right up.

Could the needle and seat be leaking fuel when sitting and flooding on start up? They are new and freshly adjusted. But I guess they could be. But it did this the first time I tried to start it meaning dry carb bowls.

Do you leave your fuel hose connected when not in use? Yes.
 
Re: Runs great, won't start

Have you tried a shot of starting fluid when it is cold? I know some guys swear this will "ruin" your motor but I think it is worth a little wear vs the wear on your starter and selinoid. I had a 71 evinrude that did the same thing. when I shot a small amount in the carb, it fired right up and got the juices flowing. i only had to do it the first start of the day, after that it would fire up quickly with a little choking. Some motors are just cold collarded. I don't think anyone can truly explain why, it just is what it is. I have a motorcycle that runs like a cheeta, but it is the most cold collared motor i have ever seen. It takes a good 3 minutes to get the damn thing out of the driveway.
 
Re: Runs great, won't start

Figured it out. The triangle knob on the primer solnenoid was turned up. In any position but all the way against the stop pointing toward the carb end it would pulse fuel with or without pushing in on the key. So it was way flooded.

I did go ahead and replace the fuel line/bulb assembly as it was old, leaky and stiff. I would like to install a fuel filter back into the system. The fuel pump has a screen but I thought a filter should be in there too. The old set up was a filter before the fuel pump in the line between bulb & engine. Anything wrong with this?
 
Re: Runs great, won't start

Go ahead & install the filter as mentioned. Note the arrow on the filter which shows the direction of fuel flow.
 
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