Marinette Boat Forum

Question about fuel here. In getting my 440's started for the first time in 12 years my engines have lost prime a few times. One being after I pumped my tanks out and now after the carbs were removed for rebuild? I spent 5 hours today with a mechanic and we primed the carbs a dozen times with a bottle of gas. Pumped the crap out of the throttles and I could never get the fuel line to pick up fuel from the tank. The engine would run as long as we were adding gas by hand but nothing at all when we stopped. Shouldn't there be a anti siphon valve to keep the lines from running back into the tank? Just seeing if anyone else has seen this? Previously when it happened I spent two days and finally was able to disconnect the fuel line, use a transfer pump to get fuel into the line and then finally after hours of tries the fuel pump picked up and it pumped like crazy. Is my pump bad? When it has fuel it sprays it across the bilge but it doesn't seem to get primed. I don't want to have to do this process every week if I'm gone for a week a two. Is it because the carbs were removed for rebuild?

I have had the anti syphon valve for the generator stick several times. They locate them right off the top of the tank, threaded onto a nipple coming out of the tank. Also make sure you have no leaks along the fuel lines. A pinhole can suck in enough air to stop the draw of fuel. Good luck

Disconnect the fuel lines from the main tank and try running from a remote tank, if it runs replace your anti siphon valves. You sure your pumps are good after sitting for twelve years?

Once primed the pumps will pump like crazy. This is the second time I have lost prime on them.

Put a primer bulb between the tank and pump. It will also give your starter motors some relief.

is primmer bulb an uscg approved item for inboard use??

Don't know but can tell you mine have been on for several years. After the boat has sat for extended periods I squeeze the bulbs until I can see pressure on the gauges and it fires right off. One thing I will say is crank it over several times before priming to get oil to the top of the engines, avoiding dry starts.

Not sure if they were originally equipped with them, but mine has a set of stainless/bronze ball valves in each fuel line. I shut them off when the engines are off, never looses its prime. As liquidplummer stated, a pinhole could be a problem, you will never notice fuel leaking, but it will let in just enough air to loose prime. Used to see that all the time back when I was wrenching on trucks working for Caterpillar.

I got it primed back up finally. I will try shitting the valve off on top of the tanks if I am not going to be cranking her for a few days. Carbs back on now so hopefully I will be good.

replace the pumps,dont get out there with pumps that have set up dry that long ,your asking for trouble. (mechanic?) hmmm