350X stalls when coasting with clutch in?

[Yamaha Tri-Moto]

Not sure what could cause this.

It idles pretty good, but does take a couple seconds to idle down again.

When coasting in a higher gear with the clutch in sometimes the engine stalls out.

Any idea what the problem could be?

Thanks

[Tri-Z 250]

Lube the cable while the cap it off the carb inspect the clip and retainer for correct position. Cable lube tools are a $12 item and are very handy. I recommend doing the job loose of carb as you want to flush out the grime and not drip into the carb it self. I use WD40 to the point that it’s running clean throughout the inside and the dirt grim appears out of the cable.
Hit the clutch side while your at it really helps with pull feel.

[Yamaha Tri-Moto]

Thanks I'll give that a shot.

Would the mixture screw on the bottom of the carb have anything to do with the engine stalling when not under load?

[Dirtcrasher]

When you're coasting it's your idle/pilot circuit.

IDK if you have any mods (exhaust/carb/cam/piston etc), but that would be the pilot circuit which is part of the fuel screw too.

I'd make sure the fuel screw is in correctly screw, spring, washer, o-ring - in that order and gently bottomed then backed out 1.5 to 2 turns. If a pilot requires more than 2 turns out, bump up your pilot 1 size.

Sounds like you like your idle where it is set now, and don't want to increase it, it's when you coast that it starts acting up. So, you may be too rich or lean in another circuit whereas when you let off and coast, the motor is still dealing with lack of or excess fuel.

That's my best guess for you, if you have mods or different jets that may be the key...

[Yamaha Tri-Moto]

When you're coasting it's your idle/pilot circuit.

IDK if you have any mods (exhaust/carb/cam/piston etc), but that would be the pilot circuit which is part of the fuel screw too.

I'd make sure the fuel screw is in correctly screw, spring, washer, o-ring - in that order and gently bottomed then backed out 1.5 to 2 turns. If a pilot requires more than 2 turns out, bump up your pilot 1 size.

Sounds like you like your idle where it is set now, and don't want to increase it, it's when you coast that it starts acting up. So, you may be too rich or lean in another circuit whereas when you let off and coast, the motor is still dealing with lack of or excess fuel.

That's my best guess for you, if you have mods or different jets that may be the key...

Thanks for the info, the bike is all stock aside from a supertrapp exhaust. I think it has 4 or 5 discs in it and I've heard that that is the closest to how the stock pipe would be.

I'll adjust the idle screw a a bit. I have the mixture screw set to 1 3/4 turns out as I think that is what the manual said was the factory setting. I guess I may have to adjust that as well to compensate for the exhaust. Would you figure in or out?

[350for350]

I'm guessing that "closest to stock" isn't very close. The original mufflers on these trikes were pretty restrictive. I'm guessing that you'll have to dive into rejetting.