3 hp lightwin worn s/s needle valve

Canoe2

Petty Officer 2nd Class
Joined
Jul 22, 2012
Messages
136
Hi, another carburetor question here, I've got my carburetor rebuilt, including the removing the core plug, cleaned the fuel filter and replaced the gas line, but still having trouble with getting and keeping this motor running. I noticed the slow speed (and only) needle valve on it is somewhat worn and grooved at the tip, but should that be giving me this much of a problem? I had it running for a while but only with full choke and since i tried to adjust it to run properly, I can't get it to stay going. I have it initially set at 1 and 1/2 turns out.Part of me is tempted to drop in an identical carb I have from another one i have running like a top (thanks to iboats for that advice too by the way), but I hate to go that route if there is a simpler solution. Thanks.
 
Joined
Oct 22, 2007
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2,598
Re: 3 hp lightwin worn s/s needle valve

Let's think about this.

1)You're having trouble with the engine running properly at slow speed.

2)You've identified a problem with the slow speed needle in the carb.

I think there's a pretty good chance you've identified the problem. Of course it's always possible that's not it, but you'll never know unless you replace that needle. (Every engine manual I've ever seen says that worn or gouged carb needles will cause running problems and should be replaced.)
 
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Canoe2

Petty Officer 2nd Class
Joined
Jul 22, 2012
Messages
136
Re: 3 hp lightwin worn s/s needle valve

To be fair, it isn't just a slow speed problem, but there is no high speed valve on this one. I just wanted to verify my thoughts on the problem were heading in the right direction and i hadn't missed something else. I have a good line on a couple of other similar motors right now so I should be able to get something going with the other parts. Thanks.
 

nwcove

Admiral
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May 16, 2011
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6,293
Re: 3 hp lightwin worn s/s needle valve

does the butterfly open at the correct time in relation to the mark on the armature plate cam? a wonky needle will cause some issues, but the motor should still run "reasonably" well none the less. jmo
 

Canoe2

Petty Officer 2nd Class
Joined
Jul 22, 2012
Messages
136
Re: 3 hp lightwin worn s/s needle valve

I will try to check that out tonight, been too busy with the kid's hockey season. Thanks.
 
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