My Zip 50 2T wouldn't start yesterday morning but it was running fine at the weekend. There was also a tell tale strong smell of petrol in the garage. The plug was soaking wet so I dried it off and tried again , No good. Started to strip parts to get to the carb and when I opened the air filter box about a half a mug of petrol poured out. Dam good job it didn't start. So assuming the float valve needs replacing I have ordered a servicing kit but I can't help wondering if that amount of fuel should have passed through the carb? If anyone has had a similar experience I would be interested to know any details. The vacuum petcock is only a year old so I'm hoping the servicing kit should be the answer. One more thing, what a pain it is working on the air filter box with it being tucked behind the body panel, any one have any tips? Thanks, Graham
New float, hinge pin and float valve fitted, so far so good. Thinking back, I did get a fuel smell a few months ago. Thought it may have been the petrol cap seal so replaced that and the smell disappeared. Obviously there was more going on. Just can't get my head around the fact that there is no means of discharging the excess fuel to waste, so it would be visible sooner, rather than letting it all accumulate in the air filter box???
Normally it leaks out the airbox. Its not the end of the world if you try starting it like that, it will just smoke a bit more than normal. Its quite normal for fuel to go back through the carb when you try starting a bike.
I was expecting an overflow and to discover the evidence on the floor beneath the carb. Ex-firefighter you see, I can't help myself. Learning as I go. Thankfully the Zip has been well behaved since the repair.
Back again. Another mug of fuel dumped into my air filter. So back in October I fitted a new float valve, hinge pin and float and things have been going along fine. I also remember that the guy I purchased the scoot from said that he replaced the vacuum tap in September '17. I don't use the scoot that much, it's only covered about 10 miles in the last month but that surely shouldn't be a problem. All I can come up with is perhaps fitting an inline fuel tap??? I would really like to get to the bottom of this problem so I would be grateful if you guys have any ideas. Thanks
Have you checked the reeds That can account for fuel in the air box if there worn and not sealing properly Not sure about a mugs worth though
It's the fuel tap, replace it. When the diaphram doesn't close properly, fuel leaks past it, fills up the float bowl. The float needles on these scooter carbs are not like the bigger bikes carbs where they definately shut off the fuel supply when they get full. They still allow some fuel to get past, hence the vacuum operated fuel tap. Your carb has a slight backwards tilt to it, hence the fuel is overflowing from the carb and back into the airbox. I had a 100cc peugeot that filled the engine up completely with fuel. It hydro-locked the engine. When I took the plug out and turned it over I had a huge spark plug hole sized jet of fuel come flying out the engine. If you want to check the fuel tap, disconnect both the fuel feed and vac lines from the carb, put the fuel line into an empty jar, suck on the vac pipe, fuel should flow freely while you maintain the vac pressure. When you stop sucking on it, the fuel should stop flowing when it empties the pipe. If it continues even a small amount the diaphram is shot. Simples.
Sam, apologies I missed your response. I have replaced the reed valve within the last 12 months so hoping that might be OK. Thanks.
