Flooded Airbox.. By kbuddington89 (Read 2,432 times)

[kbuddington89]

Hey guys, I suppose I'm a noob, but this is a pretty strange problem. I just bought a Bashan 50cc scooter a week ago, its a 2011 model, brand new, I am the first owner. For some reason, the past couple days, the engine would randomly not start, and then I opened the filter box to see if there was any clogs, as I was doing a checklist to make sure the engine had fuel, air, and spark. I opened the airbox/filter box and to my surprise it was soaked with gasoline, and it appears that gasoline is seeping into the airbox from the intake hose to the carb. What could possibly be causing gas to come up through the carb and out into the airbox. Not making much sense to me. Any ideas?

[Bashan]

That sucks, especially on a new scooter. I thought maybe the quality was coming up on the new scooters but that sounds like business as usual. Your carb float is probably sticking. You'll have to pull the brand new carb and check it. Do you know how to do that or do you need some assistance? Rich

[abispax]

if you bouht it new, just take it back or make them give you anotherone....

[kbuddington89]

@ abispax, I have a 6 month Engine part warranty, but the place I bought it from "ATVs For Less", has no refund or return policy, you buy as is. I can get parts replaced for free but I have to pay for labor.

@ Bashan, yea, I'm pretty sure I can pull the carb off, I'm pretty savvy with Harley and Jap Motorcycle engines, so working on a scooter shouldn't be much different. I was thinking something had to be stuck inside the carb, being as thats the only way fuel will make it into the Intake/Airbox. It doesn't do this often....I'm starting to wonder if it only does it after the engine gets really hot. I noticed the two times it did this, was when I made a straight 40 mile treck, non-stop. Other than this happening, the scooter runs great, looks great. So hopefully it's just a stuck float....but what you mean is that the float gets stuck and then the carb just fills up and pours out into the Intake?

[Alleyoop]

You will always get a little bit of gas blowing back into the Air Box( but just a little). If there are PUDDLE of gas the air box or the Filter is ACTUALLY SOAKED with gas then yes it is Flooding at times. Take the carb bowl off and clean it out there may be some crud and at times the crud makes it up to the fuel inlet and impedes the plunger from closeing the fuel inlet hole and allows fuel to keep coming in. Also check the Float Plungers rubber tip for damage or varnish on it as well as the fuel inlet hole itself.
Alleyoop

If this is a 2 stroke what usually causes that is the REED VALVE is not closeing or is damaged and blows gas back into the carb.
Alleyoop

[Bashan]

Alley's right on about how to clean the float mechanism. Pull the bowl off and you'll see, it's a very simple device. The warranties on scooters are practically worthless. Most vendors tap dance around and do everything they can to get out of sending you one small part. If you can't get the carb working right you can get a GY6 new carb for about $30.00 and just slap a new one on. You'll save yourself a lot of frustration. Just think about how little you paid for the thing to begin with, that's the upside to Chinese scooters. Rich

[alrider]

Had a similar issue on a 150cc GY6 engine on a dune buggy. Turned out to be a bad vacuum fuel valve/petcock. Not sure if you have a manual petcock or the vacuum fuel valve. If it is the vacuum fuel valve, unplug the line running from the valve to the fuel filter and it should only empty the fuel from the line, not continue to flow. If fuel runs out constantly with no vacuum applied to valve, valve is faulty.

[kbuddington89]

Yea, I was working with the carb, and I noticed a hose running from the front of the engine (actually at the top of the "jug" I suppose), and it runs to the intake hose between the carb and the airbox. I removed the intake hose, and the hose from the front of the engine, and I noticed there wasn't much wetness in the carb or the intake hose, but the hose coming from the front of the engine appears to be wet. Also it is a vacuum hose as well. I turned the idle way down on the carb, and I haven't had any more flooding problems. I'm assuming the fuel/air mix was out of wack. Cus one way gives you more fuel and less air, and the other more air and less fuel. I believe I was getting to much fuel and not enough air, thus causing the gas to fill into the airbox. Eitherway, I appreciate everyones help, if I have anymore problems I'll ask.

I do have a question though. I recently completed the break-in period on my scooter and it says to change the engine oil after the first 300 miles. It also says to change the gear lube after 300 miles. I used Quaker State Ultimate 10W-30 for the engine oil, and MasterPro 85W-90 GL-5 Gear Lube. I was unsure at the time, but should I run 10W-40 for the engine oil? I didn't think the oil would need that much viscosity for a moped, but you never know. Also, is that an adequate gear lube to use?

And another question, does anyone think it worthwhile to add one of those "Performance Boxes" to my moped? A friend told me that they plug in next to the battery, and its pretty much like a Cherry Bomb for a four-wheeler. Just enhances torque and speed. If it's a good idea, anyone know of a good brand to buy?

[sprocket]

Check the vacuum lines, particularly to the petcock and make certain the spring clips are in place...I have seen defective petcocks fail to close properly and fuel siphons into the carb and airbox.

Run the oil the manual says The gear oil is fine...

Save your money on the performance box... nothing you plug in anywhere will increase torque. An adjustible CDI, may give you a bit. If you want to shift the power curve, start with the CVT, experiment with weights and sliders etc...