Motor Problem

[Flint River Pirate]

Tuesday I bought a little 1998 Sears Gamefisher 3hp from a buddy's dad. It is an air-cooled little motor made in Japan by a company called Tanaka, it looks brand new. When I picked it up he said that he dumped the old gas out and drained the carb then put fresh gas in because it had been in his barn for 4 years. . He fired it up and revved it and it sounded perfect. Well yesterday I put it on my little Gheenoe and fired it up. I decided to let it idle for a few minutes. It ran about 2 mins then died. I cranked it again and it fired up.....ran 2 mins and died. I drained the carb and took off the fuel filter and it looked like there was sand inside at the bottom. I cleaned it out and screwed it back on. Now I couldn't get it to crank....at all. It has a tank on top of the motor and I made sure the vent was open. I think I flooded it so I gave it about 20 mins and tried again and it fired. This time it will idle without cutting off. I took it to the pond to try it. I ran it wide open and it will fly but after about 100 yards it choked down. It didn't die because I put it back to idle, waited 10 seconds and took off again. It will run about 100 yards wide open and start sputtering. But it will run at idle all day long and even half throttle is better. Do you guys have any idea what's up or what I can do? It is a 2 stroke air-cooled motor. Thanks.

Dave

[Ty one on]

FRP,

Sounds like you need to open the air valve at your gas cap. If your using a seperate gas tank be sure your hose isn't kinked and nothing is sitting on the hose.

Good Luck,

[Flint River Pirate]

Ty, It has a self contained tank on top of the motor. I made sure the vent was open also. Thanks for your reply.

[tin can]

I would suspect, on that particular motor, the fuel is gravity fed. That would eliminate a fuel pump issue. A couple of things come to mind. There might be trash or varnish in the carb. A good carb cleaning will solve both problems. The high speed jet is usually screwed into a stem that sticks down into the carb bowl. If the jet is partially blocked, or restricted, the motor will lean out. When you clean the carb, use a small piece if wire to open the jet. If you have access to compressed air, blow every passage in the carb to clear them. The other thought is a little bit of water in the fuel. But, usually, if this were the case, it wouldn't run at all. You mentioned a dirty fuel filter. Is that filter mounted to the engine, or in line? I would also replace the filter with a new in line filter, as well as clean the carb.

[Flint River Pirate]

TC, it is gravity fed. I say fuel filter but it is a little plastic cup on the bottom of the fuel shut off valve. That is what had the sandy looking stuff in it. Thanks for your advice. I will take the carb apart tomorrow and see if it is dirty. I just don't think it can be anything major, it runs too smooth at idle and the brief 30 seconds before it chokes.

[chugbug]

I would also suspect a fuel filter problem.

[Jumptrout51]

Carb jets.

[Joe]

Did you see or clean out the brass screen in the top of the bowl you removed?

[Sea Fox]

Just a thought in addition to the carb cleaning is the fuel lines dryrot sometimes and it could be sucking air under pressure. Good luck with it. SF.

[TroutTrent]

[quote="tin can"] You mentioned a dirty fuel filter. Is that filter mounted to the engine, or in line? I would also replace the filter with a new in line filter, as well as clean the carb.

Sounds to me like it's starving for gas if it will idle fine but cut out at WOT,, I would start off simple by just replacing the filter and go from there

[wevans]

Start really simple and take the cap off the tank, then try running WOT you may just have a stopped up air vent

[waterman]

had same problem with mine. had to take carbs off and had them cleaned, also put a in line filter on. Have not had any more probleems since I did this

[Flint River Pirate]

OK, here is what I did today. I took the fuel lines off and blew air through them to ensure they weren't blocked. I took the bottom off the carb and it looked clean. It seems to be getting better because now it will run, sputter, then pick back up. I could use it like this but it would be frustrating.I also tried taking the fuel cap off wevans. I have exhausted anything I know to do, plus I am not good with engines so there may be something I am overlooking. I don't think there is anywhere air could be leaking in. Is there more to cleaning a carb than to take the bowl off? Thanks everyone for your help!

Dave

[dolphinatic]

Did you check the flux capacitor????

[Flint River Pirate]

Did you check the flux capacitor????

Tom, yeah I checked it earlier, it is putting out exactly 1.21 Jiga-watts