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fuel pump problem on MBL engine

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jwoldeboat
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fuel pump problem on MBL engine

Post by jwoldeboat » Sat Jul 02, 2011 6:03 pm

I put a new fuel pump on my mbl engine last fall and ran the boat without any problems for maybe three or four hours before winterizing the engine and putting the boat away for the winter. Put the boat in the water yesterday and expected it to fire right up--Wrong !!-- After checking many things found that the fuel pump was not filling the carb and when trying to use the primer lever found that it did nothing. Took fuel pump off and took it apart and looked at the two little rubber valves to see if some dirt was causing the problem but they appeared to be fine so put it all back together and back on the engine, not a fun job with my old body in cramped quarters but a lot of swearing got me thru the ordeal. Now I think maybe it will work--- Wrong again !!! More swearing and I am now reaching out for any help i can get to help me solve this problem and hopefully without buying another new fuel pump. Thanks in advance for any ideas or suggestions on what the problem might be and how to fix. Joe

farupp
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Post by farupp » Sun Jul 03, 2011 6:11 am

Joe, make sure the fuel line valve on top of the fuel tank is open. Maybe your fuel bowl float in the carburetor is stuck in the closed position. Try tapping the side of the float bowl with a small hammer. Also try tapping it where the fuel line goes into the carburetor from the fuel pump. Then try the priming lever.

Is the glass bowl full of fuel? If you disconnect the fuel line at the intake if the glass bowl you should be able to feel suction when you operate the priming lever. If you don't then you may have a pinhole (or larger) in the fuel pump diaphram.

Try all of that and see if you can get it to work.
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

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Mark Campbell
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Post by Mark Campbell » Sun Jul 03, 2011 6:48 am

Hello Joe.

A few questions as well here to help.

When you say (write) new fuel pump , does that mean it was restored with a new diaphragm?

Not to assume, I have some questions to help figure things out

...was the new diagram one that is resistant too ethanol ? (not the end all, just letting you know some material is)

When you took it apart...during reassembly did you keep some pressure resistance on the diaphragm by pressing the armature while tightening the diaphragm screws. ( vice helps here as a third hand) it needs some movement freedom in addition too the rubber flex ?

As stated above may I repeat a few things? The primer should give a gafump kinda sound indicating movement inside. Sometimes it can take 12 or more quick priming bursts to pull an empty line.

The line will not prime if the the primer jar gasket is leaking air. Make sure the jar is tight, take off the jar and check the gasket for breaks or cracks.

Not for every one , but it works for me (I am a smaller guy) if you can , blow on the line from the pump side line and listen for bubbles at the tank (an appropriate hose can be substituted here too) This removes all doubt about a clog.

I hope this helps your thoughts. Have good boating days . Mark
Apprentice too Dale Tassell from 1985 till current. Too listen is to learn.

1933 CC Split 15.5 Model 300
1942 CC Special 17
1946 CC Deluxe 17 (2)
1949 CC Deluxe 17
1956 CC Cavalier 15

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Mark Campbell
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Post by Mark Campbell » Sun Jul 03, 2011 6:59 am

PS...REMEMBER when the pump is reinstalled that the arm goes 'against' the lobe and not accidentally over. This can be a bear of a job depending on the stroke position of the lobe too pump arm.
Apprentice too Dale Tassell from 1985 till current. Too listen is to learn.

1933 CC Split 15.5 Model 300
1942 CC Special 17
1946 CC Deluxe 17 (2)
1949 CC Deluxe 17
1956 CC Cavalier 15

jwoldeboat
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Joined: Tue Jan 09, 2007 7:23 pm
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fuel pump problem on MBL engine

Post by jwoldeboat » Sun Jul 03, 2011 9:07 pm

THanks Frank and Mark for the feedback with all of your ideas and suggestions on what to check and do on the fuel pump and fuel system. Went over all the items suggested to make sure everything checked out ok.I then tried primeing the system with the primer bail but it would still not prime the bowl, a friend suggested that I undo the rubber fuel line where it goes on the copper line ,lift it straight up and pour gas in the line and fill the glass bowl while operating the primer bail and all of a sudden the primer bail worked and primed like it should. Funny thing is that I did this procedure the afternoon before and could not get it to prime,I think the fuel pump fairy's came and worked all night to fix the problem!!!. Still not sure what caused the problem from the begining but I would like to think maybe it is the wonderfull ethanol gas and the effect it might have on the rubber parts and diaphragm. In any case I am going to order a fuel pump re-building kit to have it on hand if I have a problem later on. Re- launched the boat this afternoon and it ran great like there never was a problem !!! Thanks again and Happy Fourth Of July !!! Going boating tomorrow after this eight year boat restoration project is finally finished with boat in the water and running !!! Joe

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