How to Check Auto Choke

[gary]

I have a 2003 Yamaha Vino 50 that I bought used. It has trouble starting even when outside temperature is not cold. It catches and starts to run, but dies when throttle is applied. Start again - dies again. This goes on until the engine warms up a little, and then it will run (though a bit rough). I've read that it could be an auto-choke issue and that I should check the operation of the auto-choke. How do I do that, and what should I be looking for it to do while I'm checking it? (PS - scooter has new plug, clean air filter, etc. -- all the obvious remedies.)

[90GTVert]

:welcome:

As it heats up, the enricher should be pushing the needle outward to block off a fuel passage. When cold you get additional fuel to aid cold start and idle. As it warms addtional fuel is blocked off. If it's not starting well due to the enricher, I'd think it would have to be stuck somehow and shutting fuel off all of the time. No power or not expanding would mean it's a little rich all of the time, so it would likely start fine but run poorly once warm.

I pull it out and apply power to watch it expand, but you could check it cold and then let the scooter run for a few and check it again quickly. You should be able to tell if it's moving. If it doesn't move at all, make sure you've got power to it when the engine is running.




You may also want to try adjusting the idle mixture and speed settings with the engine warmed up.

[helirlc]

I have a Bennelli Andretti X50, it seems the choke is not working, before I screw it up I need to know how it works electrically. Your video seems to have a variable voltage flow to the coil to control its movement. How do I test the coil, and what actually gives or sends the power to the choke coil? and how you test it.

Thanks
Russell

[dennis5150]

This was an issue on the Vento the choke / enrichner was stuck open "choked" it started and ran but it was rich, I replaced the choke/ enrichner and the new one is evidently stuck closed as it won't start when cold, apply 12 volts the coil spring will slowly heat-up pushing the choke/ enrichner closed

[texasliam]

Does a Honda met have one of these. If so I don't see it

[pinkscoot]

Liam, yes the enricher is also referred to as the auto choke. It doesn't choke in the traditional manner but opens up a passage that richness the mixture.