'72 70Horse Johnson Outboard Motor

[Tonobo]

Vaccum lock in gas tube
Symptoms: Will run at top speed for 25 to 30 minutes. Motor will surge, then slow down, surge, then slow down. Then the motor, I think, will die for lack of fuel.
Could it be, that I sealed the engine compartment?
Thanks in advance.

 

[tashasdaddy]

Re: '72 70Horse Johnson Outboard Motor

have you tried pumping the bulb when it's doing this? what were the results. it sound more like a power pack, or coils getting warm and failing. had a 73 50hp that did that.. was power pack.

 

[Tonobo]

Re: '72 70Horse Johnson Outboard Motor

The bulb stays flat.
Sometimes does not have power to get up on a plane.
Feels like its definitely a vaccum lock. I have taken the cap off of the gas tank when I fondle with the connection between the gas can and the gas hose, I can get air in the ball. Then I try to pump more gas into it. Sometimes it works and others it wont give me the power; however never left us stranded before. Is possible coil's are heating up with the surging that sometimes occurs. There is one time I started the engine in neutral during one of these episodes and the engine went straight to high RPMs. Had jammed in the gear before RPMs got too high. Ran it for five minutes and that problem has not occured again. I apologize for all the text but I can't tell you how much I appreciate your response. Thank you.
---
Yes, Siberian Huskies do rule, espiecally my Aisha

 

[tashasdaddy]

Re: '72 70Horse Johnson Outboard Motor

i think with just hit the problem, it's starving for gas. the bulb stays flat. something between the bulb and the gas in the tank is clogging up.. is the fuel line connected properly the bulb has an arrow on it, that points to the engine. (very stupid feeling but common mistake) the gas tank has little pin that is depressed when you connect the fuel line, (this is designed to keep fuel from leaking from the tank, when line is disconneted. this may not be opening the fuel line. next the pick up tube in the tank, maybe clogging. i live on the west side of Jax near 295 and wilson, i see you're in Green Cove. check these things out and let me know.

 

[Tonobo]

Re: '72 70Horse Johnson Outboard Motor

Thank you so much for all of the help you've given me. I'm not much of an internet/computer man, of course my brother who typed this up for me. But I can see that the internet is a very useful medium. Again, thank you for all of your help.
The arrow is pointing in the right direction and I've put in a new tank. That doesn't mean, as you say, that something in the tank is clogging up the tube.
As for my engine cover, that can not be too tight?
I will try these things as you say and will reply with my discovery. Thank you
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I know I am getting good advice for how can it be bad coming from a husky man?