suzuki O/B 4hp

[jiggler]

I have a 4hp suzuki engine about 5 years old. It has had about 20hours running in fresh water . The engine was then laid up . Since starting it this year it will not idle.
it starts immedieatly on choke and will continue to run on high revs when choke is pushed off and throttle opened. When throttle is eased it will not idle but eventually peters out. I have put carb cleaner into petrol and also sprayed carb cleaner into air intake at choke. I have also dismantled carb but find no blocked jets. Any suggestions?

<hr width=100% size=1>W. L.Topping

 

[Davy_S]

Have you tried to ajust the slow running screw ! its on the starboard side of the carb. if not then its possible that your pilot jet is blocked.

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[jiggler]

Davy-S Thanks for the info. can you tell how to locate the pilot jet.

<hr width=100% size=1>W. L.Topping

 

[extravert]

Does this engine have a separate fuel tank and fuel pump? I had a similar problem where an outboard would run at any revs above idle, but left to idle would stop after a minute or two. After squeezing the bulb it would immediately restart and repeat the effect.

I found the problem to be in the fuel pump. One of the non-return valves was not seating properly. The pump worked effectively when the revs were up, but at idle speed the leaky non-return valve was letting too much fuel back to pump at all.

I cured this problem for nothing. The non-return valve was a little flap of black rubber. Inspecting it closely I could see a slight indented ring where it fitted over the hole from the inlet pipe. Solution - I turned it over.

<hr width=100% size=1>One day, I hope to own a real boat.

 

[andy_wilson]

Is the fuel fresh?

If not, discard and start with fresh.

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