basic carburetion...I don't get it.

[rivet]

I've been given a mercury 9.9 (1991 -thanks Laddies)and I can't get it to start. I removed the cover and started it by squirting gas/oil mix directly into the carb. It idles perfectly if I keep squirting it. It'll be hard to fish and squirt at the same time so I need to fix my carb! On to testing...<br /><br />I removed the hose that went from the fuel filter to the carb fuel intake and pumped the bulb. fuel flowed freely. Great! Next I attached a spare piece of fuel hose to the fuel intake on the carb and blew into it. Nothing. It was blocked. That explains why it wasn't getting any gas. At this point I figured I'd go inside and look up info on getting a carb rebuild kit. About 30 minutes later I went back outside and blew on the hose again only this time it was open! WTF? As I blew I could see the blue-ish gas flow from the vertical tube (venturi?) into the carb throat. I immediately re-attached the fuel hose and started it up. It ran for about 30 seconds and quit. I then re-attached my fuel hose and blew. Sure enough it was blocked again.<br /><br />Is this normal? Does this have to do with the float level in the bowl? Any help on this would be GREATLY appreciated. Thanks in advance.

 

[Laddies]

Re: basic carburetion...I don't get it.

Your inlet needle is sticking, with a little luck you can get away with cleaning the carb and might not need a kit

 

[rivet]

Re: basic carburetion...I don't get it.

You nailed it Laddies. Thanks again. I ran out and bought carb cleaner and cleared it.

 

[rodbolt]

Re: basic carburetion...I don't get it.

hello <br /> you really should dissasemble and clean the carb, go ahead and replace the fueel pump diaphrams as well. the gasket kit is cheap. less than 10 dollars I am thinking. a clogged jet or a partially blocked needle can make a sweet engine a pile of pistonless rubble in a matter of minutes while cruising about.

 

[Chinewalker]

Re: basic carburetion...I don't get it.

Sticky floats usually mean goo in the carb. Goo in the carb may work "sometimes", but not others. Take it apart and clean it up. Install the kit as advised above. You'll thanks us later as a much larger boat is bearing down on you because the helmsman is more interested in the bikini on the forward deck than what is forward of his deck...<br />- Scott

 

[rivet]

Re: basic carburetion...I don't get it.

Thanks everyone. I do plan to rebuild the carb. I think it's the 18-7212 Carburetor Repair Kit and it goes for $30.00. <br /><br />I've heard that the 9.9 HP is the same engine as the 15 HP and that people convert them by changing the jets. Anyone here ever done that? Sounds risky...