Suzuki 4 hp problem

[seascene]

1985 4 hp 2 stroke engine: Will not start except at near full throttle. Once there if you try to slow down the engine quits. Anyone have a similar problem with an older 2 stroke. I will be doing the usual thing like clean out carb, change the fuel ...all the typical stuff. If the problem is still there I am defaulting to the fuel pump diaphragm unless there is something I might be missing.. thanks

P.S. I will be updating to a newer 4 to 6 hp (sailboat dingy) ... so if you have one for sale (short shaft)... please get in touch.

Thanks

 

[GLG]

Have an older honda kicker that does that. What worked for me was to remove the air/fuel mixture needle valve and blow compressed air in the opening to clear the idle circuit in the carb. Most carbs have 2 circuits, one for idle and the other for the main fuel. The idle circuit has a needle valve screw that sets the air/fuel ratio. When you remove it you need to put it back to where it was set. How I do it is to gently turn it all the way in counting the turns that it takes to seat. Make sure you don't reef on it as that can damage the seat. Once I have that number I then remove it and apply the compressed air. Put the needle valve back in to seat then back off the number of turns that you counted in the first step.