1973 Johnson 25R73A Fuel pump / fuel tank issues

Riley3443

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Hey everyone I'm new here and I did do a fair bit of reading before writing this but could not track down my issue exactly and I'm new to the boating world so I'd figured I'd post here.

I recently purchased an Alumarine 14ft glider with a Johnson 25hp and although it runs good there's a few issues. Mainly under about 1/3 throttle it needs to be primed to stay running... Not good for trolling. I don't think it's a carb issue because it runs good when it gets fuel.

​​​​​​Now I noticed the top valve on the original OMC metal tank seems to leak a bit so I want to go ahead and rebuild this part. I know I will need new core plugs and orings and was wondering if they are metric or standard as I want to buy an oring kit as opposed to ordering them from the dealer. Any advice or links to rebuilding the valve assembly would be appreciated and any other replacement parts. I would like to fix this tank because it's original and matches the boat.

Second can I replace orings in the connectors of the fuel line as it would be cheaper then buying a new fuel line. Or would I be better off buying a new assembly? If so should I get the one from evinrude / Johnson or are any other brands good.

I want to eliminate the possibility of air leaks causing the stalling problem as the fuel pump seems to work as it will run at higher speeds with no issues. I was thinking at low vacuum the air leaks may cause it to lose prime..

Thirdly if the above doesn't fix the problem is a Sierra 18-7350 the correct fuel pump for this and are they reliable.

Thanks for any advice!
 

racerone

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Fuel pump repair kit is about $20 or so.----Tested compression ?
 

F_R

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Off hand, I would "guess" the o-rings are standard, not metric. The one that is around the valve pin (behind the brass washer) on the tank is probably the one that is leaking. It will suck air when it does, and cause the problem you are experiencing. I don't know what size it is, other than tiny.

Sure, the ones in the fuel connectors can be replaced. Hook the old one out and slide new one in. Um....saying that about OEM ones, it's a crap shoot if aftermarket connector.
 

Riley3443

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Thanks I will replace those orings. I would like to take apart the two valves and replace those orings as well. How do I take out the valve pin is there a specific way to take out the valve retainer if the one you are talking about is behind this. It is shown in the picture below. Thanks.
 

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Riley3443

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A couple pics of the boat:
 

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F_R

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Drill or poke a small hole in the core plugs, then stick a punch or similar object in the hole and lever the core plug out. Spring and valve pin will then come out. Now stick a punch or similar object in the brass retainer and lever it out. Use a hammer and screwdriver to stake the retainer back in. Flatten new core plugs to expand them in the holes.
 
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