PRESSURE SYSTEM 1957 18HP EVINRUDE

[01SENDERO]

I have a 1957 Evinrude 18 hp motor that I am having troubles keeping it running. If I prime the tank manually the motors runs great. I have put in a new gasket kit on the tank and I have no leaks that are visible on the hoses or the connections or the tank itself. Is it possible that the motor is not producing back pressure that is needed to be returned to the tank? Is there a one-way valve on the crankcase that could be faulty? Is there any way I can check for this? The motors runs great so I hate to junk it. If anyone has any suggestions please get back to me.<br />Thanks

 

[rolmops]

Re: PRESSURE SYSTEM 1957 18HP EVINRUDE

Hello.<br />It looks like there is no pressure build up from the engine coming back to the tank.There is really nothing in the engine that can cause that.Your answer is in the hoses.You should check the one that comes from the crank case to the connector,then make sure the connector does not loose pressure and that it is not clogged.Then go from the connector on to the pressure tank.Last but not least,make sure to screw the top on tight so you don't loose pressure on that end.If none of this helps,take the filter out of the bowl and see if that does the trick.<br />When you manually prime the tank,you dont pressurize it.All you do is, you pump fuel to the carburator.You do use a double hose I suppose.<br />Good luck.

 

[alcan]

Re: PRESSURE SYSTEM 1957 18HP EVINRUDE

Did you replace the o-rings in the connector?

 

[rodbolt]

Re: PRESSURE SYSTEM 1957 18HP EVINRUDE

hello<br /> best thing you can do is convert it to a fuel pump model and get rid of the bomb in your boat<br /> when running you have a compressed perfect fuel mix. safety issues is why it went away anyway. unless you wish to keep it as a collectors item I would convert it. if done carefully it can always be converted back.<br /> good luck and keep posting

 

[01SENDERO]

Re: PRESSURE SYSTEM 1957 18HP EVINRUDE

Thanks for the info. I have repalced all of the clamps and hoses, both fuel and air. I have primed the system and soap tested all connections and hoses on the motor and on the tank. (No Leaks) I am also not getting leakage from the connector. I will try taking out the filter; I have had it out recently and it appears to be clean and free of varnish. How does a person extract those orings in the female side of that connector without damaging the connector? Can you just buy them at any oring shop? Are they made of a special material? <br />Thanks

 

[rwise]

Re: PRESSURE SYSTEM 1957 18HP EVINRUDE

OLD18<br />after the engine has ran for a moment, and dies, loosen the cap on the tank slowly, there should be presure in the tank. The seal in the cap can be bad as well, take a look at it. If there is no presure in the tank, you have a leak and. No presure = soap test will not work. New dual line is still around for those, I just replaced mine about $1.60 per foot.

 

[alcan]

Re: PRESSURE SYSTEM 1957 18HP EVINRUDE

Hi old18<br />We'll get you going here. The soap test is good and valid. The only thing is the motor has to be running for the test. There has to be presure on the tank. The thumb pump (primer button) will not presurize the tank. Prime up your motor and start it. It should run long enough to remove the connector and you should hear and see presure hissing from the male connector. It sounds to me like you may not have put things back together correctly. Do you have a plastic primer button or the aluminium button? Did you install the presure relief valve correctly? <br /> How to install new o-rings in the connector? Here is the easiest way. You will want to make yourself a jig. Get a short chunk of 2x4, 6"-8" long. Place the connector on the block face down. Trace around it with a pencil. Center two holes in the pattern. Should look like a shot gun. Bore the holes just a hair bigger than the bronze bushings in the end of the connector. Make the holes about 1/2-3/4" deep. Use four finish nails as locators,to position the connector over the holes. Now comes the tricky part. You will need a punch 31/4" long and about 1/8'dia.,a little longer is ok. Not so long as to cause it to bend or break. I always end up making mine. Sorry I don't remember what I used. Any way just polk the punch down the holes from the hose end and tap the bushings out. This way you catch all the innerds in the holes in the block. You loose no springs or washers. The o-rings are a special size, They are fatter than average. You may be able to find them at a hydrolic place or something. They don't cost a whole bunch from the OMC dealer though. Take your time build a good jig and punch. Make it out of aluminium block if you can,then you got something. Wooden prototypes work well, and last a long time. Once you get set up this job takes about five mins.tops. Be sure to save your new tools. And buy lots of o-rings. Once word gets around all your buddies will be at your house. Another idea, just for grins disconnect the fuel hoses from the carb (gas) and the manifold (air). Now hook the hoses from the tank direct, by-passing the connection. See what this does.