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1972 Johnson 85 hp (85ESL72R) Carb/throttle Adjustments

JLMEMT

Member
I just discovered that the carb cam was severely out of adjustment. With that I now am at least close to full carb travel with the throttle cable.

This engine has no high or low speed adjustment needles, everything is fixed orifices. I was really confused because the air silencer has plugs and labels indicating slow speed adjustment, however they are not needle screws and do not adjust anything. And the manual indicates that they do not have them. So apparently it was a part used on fairly different engines.

I did find that the carbs and chokes were not synced properly anymore, that should help some.

So I think that I am slowly getting close. I suspect that the fuel pump diaphragm, or bulb check valve, may be leaking as the bulb never gets hard now. At first if I pumped the bulb it would get pretty firm, so I am assuming that is how it should be.
 
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So I did get the bulb hard earlier after having confirmation that it should be. The engine ran quite well for about an hour of tubing with the boys today. And then it would die when I tried to give it any throttle. Now the bulb doesn't get hard again and it seems like it is shooting gas back into the tank. The check valve should be right at the bulb, correct? I have a Moeller tank, or two of them actually. It doesn't appear that there is a check valve there. If my bulb is going bad would that be enough to not get much fuel to the engine? It seems like it should still pull through once it is going. The better of the two tanks ran fine until it was empty. The second tank then seemed to work at first, and then I started having problems. The fuel was the same age, treated the same etc, in both tanks. If the bulb isn't likely the problem then I have to wonder if it might be either the vent or the fuel pickup. This tank does not seem to vent like the other one does and it does leak around the gauge. I will probably try to fix it as a new tank is fairly spendy and it seems structurally fine. Just trying to figure out the likely culprits so that I don't waste parts and money where it isn't going to help.
 
The bulb is a MANUAL fuel pump used to fill the carburetors.---Saves the starter motor from doing that.-----When float bowls are full the bulb goes hard.----When motor starts the bulb does nothing, and goes soft.-------Some plastic tanks have leaks on the pick up tube.
 
That's what I thought. Thank you.
That makes me wonder if the pickup was sucking air instead of the bulb pushing fuel backwards, because it seems fine in the other tank.
 
On more than one occasion have I seen issues inside these " cheap " plastic tanks.-----I prefer the older OMC metal tanks !
 
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