Carb problem on 1982 25HP Merc

[wannagofishin]

I tried doing a search but found nothing like my problem. I just got a 1982 Mercury 25 hp outboard engine. I rebuilt the carb as best I could since several parts are NLA. I can get the engine running, but as soon as the bowl is empty, it quits. I would say it was a diaphragm problem, but it is new. I have cleaned the carb, new gas tank, new fuel line, (from tank to carb)and float adjusted. I can't find a new needle and seat but am still looking. When I pump the bulb, fuel will come out the front of the carb throat and the hole at the top left (accross from idle adjust valve) which leads me to believe the needle needs replacing. <br /><br />When I got the engine, the seller told me it ran fine until he loaned it to a friend. I noticed the idle adjust valve was missing and bought a new one along with a rebuild kit. I got new plugs, tank, tank to engine line and bulb, and new fuel line to filter and from filter to carb. I did a compression test after running it a few minutes and on each cylinder I pulled 4 or 5 times. Each cylinder gave a reading of 150 psi on the third pull.<br />I have built motorcycles (4 stroke) and cars but know little about 2 stroke engines. I'd like to just buy a new carb, but can't find one anywhere. Anyone out there have any suggestions?<br /><br />Dan

 

[Laddies]

Re: Carb problem on 1982 25HP Merc

Get a factory manual and carb kit and redo the carb, it is definitly leaking by the inlet needle and the fuel pump is not working that could be the carb gasket is blocking the pulse hole to the crankcase, it sounds like the trouble could be in misassembly

 

[wannagofishin]

Re: Carb problem on 1982 25HP Merc

First, thank you for your reply. I don't have the factory manual, but I do have a Seloc (I know, I know) The rebuild was successful and the leaking only occurs when I pump the bulb. It probably wouldn't hurt to get a new valve and seat, but right now it doesn't seem necessary. I found my problem thanks to your statement about the blocked pulse hole.<br /><br />The rebuild kit didn't include a carb-to-manifold gasket so I had to buy gasket material from NAPA. When I cut it out, I didn't see the hole on the manifold so I covered it up. After reading your reply, it hit me. I removed the carb, found the hole, cut it out, replaced the carb, and now the thing runs like new. <br /><br />Thanks again for your help. It's storming here right now but you can bet I'll be on the water ASAP!<br /><br />Dan

 

[Laddies]

Re: Carb problem on 1982 25HP Merc

In most cases you can make the inlet leak with the bulb