1955 Johnson 25 horse not running

[RyanBCarroll]

I have been working on a 1955 Johnson 25 horse. Has not ran in at least 7 years. Put on coils,points,condensors,set them with a tool I bought on e-bay. I am getting good spark. I have had the carb apart 3 or 4 times now, it is clean. My pressure tank works good. It will fire for about 4 seconds if I spray fuel in the carb, or spray fuel direct into the cylinders. It will not run long, just a few seconds. Anyone have any ideas, I am guessing something with the carb, but what could it be? How are you sure that the reed plates are ok? Compression is 75 in each cylinder. Thanks in advance for your time any help will be great. RyanBCarroll@msn.com

 

[jbjennings]

Re: 1955 Johnson 25 horse not running

First, 75psi is not enough for that motor. You need at least 110psi (in my opinion) for it to run decent. However, don't freak out because your compression gauge is likely to be wrong. I've never seen 75psi on both cylinders in an 18hp or above. I would test a motor with known good compression and see what it has using your gauge. If it really is just 75psi, I'd forget working on it.

As far as the carb., I'd check to see that your float needle is opening and letting fuel enter the fuel bowl. It sounds like it isn't. Is our float upside down? It's gotta be something simple. Is your fast needle totally closed?
JBJ

 

[samo_ott]

Re: 1955 Johnson 25 horse not running

Pull the fuel hose off thew carb and pump the button on the tank. Is fuel coming out? 75#'s is low. I'm not sure if it's too low but on an engine that has sat for 7 years it's gonna be pretty dry. Hopefully it will come up with use or a de carb...