johnson 140 hp, 1992 , ethenol damaage the gas line en the primer fuel solanoid , I replaced the P fuel solanid and I clean the carburetor trought the screw inthe front of eachone of them but the motor won't start;if it does it turn off by itself. do I have to rebuild the carbuletors?
No worries,they are the tiny holes/or needles where the fuel comes out into the carburettor bore(hole in the middle where air sucks into the engine). They are very tiny so often clog up. You can get at them by removing the float bowls and blowing down compressed air or sticking a pin up or similar to check they a clear but be careful to not damage them
Thats good that that fix has got it going now. I dont have that motor so i cant comment on adjusting the carbs but since you have fixed the problem of leaking gaskets it will be running richer to what it has done previously. Check your timing as well, an advanced timing will cause a higher speed idle.
You will probably find an article on how to adjust the carbs and the timing in the topsecret files at the top of the main page