Is this vapor lock?

3angieyou · Post by **3angieyou** » Wed May 22, 2013 10:50 pm

Only happens in third gear going up hills. The bike acts like it is gonna stall going back and forth between losing power and normal speed. Only happens sometimes but it tends to be on warmer days.

fisher1 · Post by **fisher1** » Thu May 23, 2013 8:09 pm

I'd start by checking the float, float needle, and other fuel flow possibilities. I've seen vapor lock also show up at idle at stop lights and at startup when the engine's hot. Just my novice thinking.

Dooglas · Post by **Dooglas** » Thu May 23, 2013 9:48 pm

What most folks call "vapor lock" on modern scooters with a gasoline vapor recovery system is actually a problem with fuel tank venting. It typically shows up as fuel starvation after riding for an extended period. The easiest way to diagnose it is by opening the fuel cap. If venting has been blocked, you will hear a hiss - then the scooter will run fine for a while. A vented gas cap fixes the problem if you have it. Your description really doesn't sound like "vapor lock" unless there are other symptoms as well.

3angieyou · Post by **3angieyou** » Thu May 23, 2013 11:24 pm

The only other thing I can think of is that I have a 2012 stella that I bought new from the dealer a few months ago. Before then it had been sitting in their shop unwanted and untouched. When I first went to test ride it wouldn't start. The mechanic said the carb was gummed up, and took it apart and cleaned it. Started up after that. Maybe some gunk in the tank? I don't know much about this sort of stuff but attempting to avoid going back to the dealer.

Dooglas · Post by **Dooglas** » Fri May 24, 2013 3:50 am

The quick and cheap way to clean the carb is a dose of SeaFoam. If that doesn't work, disassembly and cleaning of the carb is the more complicated fix. Probably not a job for someone with no expereince and some hesitation in getting into more complex mechanical projects.