Running uber rich and can't figure out why? Check this out!

[Silar]

I posted about this in the troubleshooting section, but thought I would mention it here also as it may help people that may be having the same issue.

I've been having a bad overly rich problem on my scooter and couldn't figure it out so I started throwing parts at it like crazy figuring something would fix it.  I've installed a BBK, A9 cam, performance CDI, coil and wire, gates belt, sliders, different main jets and diaphragm needle adjustments, etc.. etc.. etc..  Also installed some new clear fuel and vacuum line.  

All of that and still had the exact same problem.  It would only go to about 10 mph... Then I noticed something...  I noticed that the clear vacuum line that is attached to the fuel pump was somehow sucking fuel into the intake directly.

If you watch the video, the vacuum line is running from top to bottom, and the fuel line is running from left to right.  If you look at the vacuum line right under where the fuel line is, you'll see something pulsing through the line.  Guess what.. That's gas!



So like me, then you will have to replace your fuel pump.  Of course I now highly recommend the clear polyurethane lines.  Thankfully I bought some and installed it or I'd still be pulling all my hair out still thinking it was a carb issue, or rings or seals bad.

[Upgrayedd]

you can just replace it with a manual petcock and cap the vacuum port on your intake. the manual petcocks hold up a lot better.

[Florida Antique]

The problem with the manual petcock is that most of these tanks are so buried in the scooter, you would have to disassemble the whole scooter to get to it to turn it off. I had a vacuum petcock do this exact thing. The service manual said to test it, suck on the vacuum line and see if gas flowed out the gas line. Well guess what, because the petcock was bad, leaking gas down the vacuum line, I got rewarded with a mouthful of gasoline. I guess the service manual was right in one aspect, I was able to determine that it was a bad petcock!

[humanshield]

Great post Silar.

Sometimes even the most experienced can overlook things or forget them.

[Silar]

Apr 28, 2015 10:38:45 GMT -5 humanshield said:

Great post Silar.

Sometimes even the most experienced can overlook things or forget them.

I know..  

It's something that I never thought would be the problem and didn't even see it since the factory lines are black.  

[scootscoot1313]

thanks for posting this. this may just help me with my problem