2006 Yamaha Vino XC50 starts then quickly dies

Lou · 10-18-2021, 03:23 AM

Hi there --
I've had my Vino for about 6 years. 2 years ago I was riding it and it bogged down. I put it in the garage and didn't take it back out until about a month ago.

I started by replacing the radiator fluid. Then I removed the carburetor and took it apart. I opened the bowl and removed the screw that was holding down the float pin. I had a heck of a time getting the float valve out. I had to pull quite a bit on the float to remove it. It was covered in green stuff which almost looked waxy.

I cleaned the carb, and then I replaced the float valve with the same OEM one. I reused the float as the kit didn't come with a new one.

I reinstalled on my scooter and kick-started it -- it started surprisingly easily and continued running -- however, gas was pouring out the bottom of the carb. I figured I needed to redo the float adjustment. I ordered a new OEM float.

I took it apart again, and replaced the original float with the new one.

A couple notes:

I had an extremely difficult time releasing the Throttle Position Sensor connector. really difficult. I did a LOT of pulling.
when cleaning the carb, i pulled off the Throttle Position Sensor (at the time I had no idea what it was). I put it back on and made sure that the throttle could still move freely.
My electric start wasn't working and I had determined that it was the handlebar start/stop unit. I replaced it with an OEM new one.
in trying to figure out why my electric start wasn't working I cleaned all the electric connectors.

I reinstalled the carb on my bike and tried to start it with the electric starter -- the starter was working, but it wasn't starting (if that makes sense). I moved on to kickstarting it and then I rolled the throttle. On the next kickstart it started then quickly died. I did this over and over -- squeezed brake, rolled throttle, kickstarted it -- it caught then died.

I checked to make sure I hadn't confused a vacuum line with the fuel line; I hadn't.

I removed the carb again, took it apart and cleaned it again. I put it back on the bike and had the same problem as before -- i could get it to catch if I rolled open the throttle, but then it would quickly die.

Here are things I'm wondering:

could I have messed up the throttle position sensor and this is the result?
could my float still be incorrect?
In changing the handlebar start/stop unit could I have done something to the throttle cable? (Though in checking it it moves freely)

Thanks for any help.