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JEdward · 31-12-2012, 10:43

After taking carb apart no less than six times, cleaning, poking holes with wire, etc. and still having engine stall problem, last night I gave up. This morning, disassembled carb again to check float valve. No visible problem. Reassembled. Cranked engine. Started quickly and purred like a kitten with catnip. I have no idea what changed between last night (would not run) and this morning, no problem? I will appreciate any thoughts.
Meanwhile, I am not sure I have needle valve adjusted correctly (rich vs. lean)? Any direction how to "tune" this will also be appreciated.
Thanks.

**noelex 77** · 31-12-2012, 11:06

Carburettor blockage is very common on these small 2 stoke outboards. I know the symptoms and clean mine every few months. Sometimes it does take a couple of goes for no particular reason.
Try blowing through the openings as well as poking with a needle.

On my Yamaha, like most, there are two common sites of blockage, the carburettor jet and the needle float valve.

If you have an internal tank often these rust internally and this blocks up the carb, but even with an external tank it is a common problem.

On the larger 8hp outboards it seems a much less common problem.

tropicalescape · 31-12-2012, 11:14

Quote:

Originally Posted by JEdward

After taking carb apart no less than six times, cleaning, poking holes with wire, etc. and still having engine stall problem, last night I gave up. This morning, disassembled carb again to check float valve. No visible problem. Reassembled. Cranked engine. Started quickly and purred like a kitten with catnip. I have no idea what changed between last night (would not run) and this morning, no problem? I will appreciate any thoughts.
Meanwhile, I am not sure I have needle valve adjusted correctly (rich vs. lean)? Any direction how to "tune" this will also be appreciated.
Thanks.

Screw all jets to the bottom ,then turn each one a complete turn out,then crank it and give it full power,adjust the High jet screw until it is running at top rpms and then turn screw back in until you notice a drop in rpms , you never want it to go to full rpms for very long only a few seconds then back it down a few hundred rpms,to set the low end just turn the jet set screw until it is at the point of 4- stroking and will take the gas as fast as you can give it to it,it should rev up as soon as the gas is given ,if it spurts and kicks and then revs you will need to adjust it until it takes the gas instanly..thats all it takes,good luck..