1956 7.5 Johnson need help again

[aaind]

So got spark now ,pump up tank start up runs little bit stops thought to pump up tank it was soft ,start right up and stops again.
Put on new line air and gas to carb and manifold ,I know tank is good just did 5 others .also wont run much past 1/2 throttle ,but runs rather smooth

What should I try ,also put new gasket for settling bowl thought it was leaking ,did not put hole carb kit in.
Thanks in advance .

 

[nwcove]

Re: 1956 7.5 Johnson need help again

sounds like you need to do the whole carb, welch plug and all. you can try setting the tank on a stand higher than the motor to see if it makes any difference ( gravity feed), but i doubt that will help.

 

[aaind]

Re: 1956 7.5 Johnson need help again

ya ,what the welch plug

 

[nwcove]

Re: 1956 7.5 Johnson need help again

the small nickel sized aluminum plug on the top of the carb, it covers the idle circuit. never do "half a carb kit". if its on the bench, do it right.

 

[aaind]

Re: 1956 7.5 Johnson need help again

if i am loosing pressure ,would there be gas coming out somewhere ?

 

[Daviet]

Re: 1956 7.5 Johnson need help again

Will it continue to run if you keep pumping the primer button on the tank?

 

[aaind]

Re: 1956 7.5 Johnson need help again

i think so dint really try but think it would ,every time i pump it up it runs

 

[Daviet]

Re: 1956 7.5 Johnson need help again

If it will continue to run by pumping the primer button on the tank, you are not building pressure in the tank. Either you tank is not air tight or the hose from the engine to the tank has a leak in it or the engine is not producing air pressure.

 

[aaind]

Re: 1956 7.5 Johnson need help again

why would the engine not produce pressure ,it runs nice if you keep pumping it up ,and tried 2 tands that were both good

 

[nwcove]

Re: 1956 7.5 Johnson need help again

two post going on the same subject but, how do you know both tanks are good? if they have been tested on other motors, maybe the male connector end on your 7.5 has a problem. ( its not a big job to connect the air line from the tank directly to the air nipple on the manifold for trouble shooting purposes)