Engine will only run when choked or partially choked.

[SeaKing15hp]

I have finally gotten good fire to both of the cylinders and I had the carb cleaned on my 1982 Sea King 15 Hp. It starts and runs when choked, and will idle roughly until you turn it off. I think that its just running way to rich. The problem comes when you try to turn the choke off.. its like you turn the entire fuel system off. I have found that it runs best when you rapidly push and pull the choke on and off. What would cause this? Thanks in advance.<br /><br />Jacob

 

[eurolarva]

Re: Engine will only run when choked or partially choked.

Most cases it is the carb. Aside from cleaning it you should get a rebuild kit. If this is a chrysler or a force the mixture adjust screw needs to come out and blast it with carb cleaner. Clean all tiny holes with carb cleaner, a thin wire and compressed air around 20 PSI. Also inspect all fuel lines for leaks. Verify that the primer bulb stays firm and does not leak gas at the carbs when you prime it. When carb is back together turn mixture screw clockwise till lightly seated and then turn it counter clockwise 1 1/4 turn. This is a good starting point. If this seaking was made my evinrude or johnson you may want to post it there.

 

[SeaKing15hp]

Re: Engine will only run when choked or partially choked.

Hey, thanks for the reply<br /><br /> The primer bulb stays firm, so I don't think that would be the problem. I haven't taken the idle screw out though. The motor was made by chrysler. Its got a Walbro LMB carb. Thanks for your help, and I'll try what you posted. <br /><br />Thanks!<br />Jacob

 

[SeaKing15hp]

Re: Engine will only run when choked or partially choked.

I really appreciate your help, but I think I have singled down the problem to a certain area. My motor is a 15 hp, and you can bolt up a 9.9 carb, and it will run, but at a lesser power and a lesser rpm. However, I switched the jets on the carbs, so the hp would be in between. I hooked up a known good carb, and the problem persists. I believe that the problem may be in the vaccume of the pistons. It's like its easier to suck gas in from the choke than the throttle. I have made sure the gasket between the carb and intake is good, and I also replaced the head gasket. The compression seems good, but I will have to find my hose to the compression gauge and get back to you with the numbers. Is there anything else to check? Has anyone ever had this problem? I guess that I may have a bad jet, since it is the only thing that I switched between the carbs. I will check it in the mean time, but see if you can ponder any other things that could be causing this malfunction.

 

[eurolarva]

Re: Engine will only run when choked or partially choked.

Might want to rebuild the fuel pump as well. Is this what your fuel pump looks like? FUEL PUMP .<br />It is possible you have a two stage pump as well. It is bigger and almost has a figure 8 appearance.

 

[SeaKing15hp]

Re: Engine will only run when choked or partially choked.

When I got the motor, it wasn't running at all. Fixing the fuel pump was one of the first things that I did. I also replaced the fuel lines with 1/4" fuel hose. <br /><br />UPDATE:<br /> I changed out the jets, so that I was running a 9.9 jet in a 15 hp carb, also I switched back to a factory type hose from the fuel pump to the carb. I started it, and to my suprise, it didnt like the choke at all, and ran pretty good not choked. I believe the jet is just not getting enough fuel in, but at least it works! I am bad about fixing more than one thing at a time, so I really don't know what helped. Does anyone know where I can get a 15 hp jet to a Walbro LMB carb? Also, what size hose should I use on this motor? I really appreciate your help. Without this site, I would be lost in the dark! <br /><br />Thanks!<br />Jacob

 

[Scaaty]

Re: Engine will only run when choked or partially choked.

Low speed jet and/or bleed passage ways plugged. Spray the crap out of the openings with carb cleaner-wear a face mask and rubber gloves