Scooter runs Only after taping off air intake - How to fix?

[John Phoenix]

I've pulled my hair out last couple of days trying to get my 150cc scooter to keep running after it sat for 9 months. I changed the gas, sprayed the heck out of the carb with carb cleaner, checked the hoses etc. I don't suspect the electronics because the bike is only 2 years old with only 150 miles on it.

I read last night a trick to bypass the auto choke by taping shut the intake holes in the housing of the air filter. I was actually shocked to see the bike start right up and keep running! Now give me a Haynes manual and I'll tear down and rebuild anything but I don't have that for this scooter and have no experience otherwise with motorcycles.

What does this tell me? How do I correct the problem? I feel the auto choke itself cannot be bad cus it's practically brand new. I do know I have to re-adjust my idle. I also know I cannot change my gas/air mixture because it's sealed inside the carb with a plug. That's set by the China factory and may not be exactly correct for my southern USA climate but the bike has been working fine until now.

Ideas? Thank you gents!

[JerryHawk250]

You will need to adjust the idle mixture. You can drill the brass plug out to gain access. My ATV did the same thing after after a few years. Adjusted the fuel mixture and works perfect now.

[John Phoenix]

Thanks Jerry. I have been dreading the idea of fooling with that cus everything is so hard to reach. I'll have to pull the carb all the way off and grab some gasket sealer in case I ruin a gasket.

Now if I understand this correctly, restricting the air tells me it was getting too much air OR not enough gas for the air/fuel ratio. Of course I want it as lean or rather stoic (which I understand as a good balance) as possible to save on gas while still running well.

I suppose this could be an indication that the carb is still not clean enough to let the proper amount of gas to get through, is this correct? (aside from the factory set air/fuel mixture)

Until I get the time to tear the carb down and adjust the mixture will it harm the bike running it with a restricted air flow?

Btw, I'm in Metairie. I wish I knew some scooter folks in my area to hang with/learn from as a buddy to help me fix such issues would greatly help.

[65cabriolet]

You say it sat for 9 months? did it have gas in it while it sat? if so idle jet is probably clogged.

[krat]

All suggestions here are valid. The auto choke might also be stuck due to that fouled gas situation.

As for access, after you drill out that plug you can access the idle screw from the side of the bike with a long screwdriver.

No matter what the problem you are going to have to remove the carb so you might as well open it up and do a good cleaning after a 9 month retirement.

I put mine in storage every winter for nearly 6 months and put stabilizer in all the tanks. It is cheap insurance against this problem.

BTW, every step of the processes we are discussing are available step for step on various Youtube videos.

[John Phoenix]

I Have to get it running tomorrow because my 2008 Smart Car died. A oily ring fell out of the back engine area which I found on the street while the wife and I were pushing the car back onto the property. Never buy Mercedes, Over priced junk. I don't just say that because of my car, my moms AMG has been in the shop for over 8 months.

So I will not be able to go buy tube of gasket sealer and of course I wont have the paper gasket that came with the carb incase I ruin it. Am I likely to need to do so? All I can do it take it off as carefully as I can and Pray the gasket isn't ruined.

Thanks so much for your replies folks.

[JerryHawk250]

Check that you don't have any vacuum lines unplugged or cracked. A vacuum leak will cause a leak condition.

[krat]

Originally Posted by John Phoenix

So I will not be able to go buy tube of gasket sealer and of course I wont have the paper gasket that came with the carb incase I ruin it. Am I likely to need to do so? All I can do it take it off as carefully as I can and Pray the gasket isn't ruined.

Thanks so much for your replies folks.

Your scooter carb will not need a tube of anything, or a paper or fiber gasket.

It is sealed using a rubber ring gasket that will require no sealant and will come off without damage if treated reasonably.

Really, you need to watch some Youtube videos and get some concept of what you are dealing with before proceeding.

Just getting into the carb is going to require some surgery that you are probably not anticipating. You will need to drill out the plug over the idle adjustment screw and you will also need to slot the assembly screws before you can open the carb to clean or adjust anything. They are all assembled with breakaway screw heads to make maintenance and modification as difficult as possible and to insure emissions compliance.

[John Phoenix]

Krat - I just found that out when taking off the carb. Go ahead, laugh at the newbie! LOL

"you will also need to slot the assembly screws before you can open the carb to clean or adjust anything." - I did not know this. Do you have a video on it?

Also, this may help you answer that as this is my next major question.. Just covering my bases..

Which one is my Welch Plug? (video I just made for you guys)



From the video's description: "Looking to adjust the air/fuel mixture on my awesome Chinese 150cc scooter. The carb is model PD24J made by " You-All " - Serial number (I think) VE CA 1016R"

Edit - I think I found the answer with this video as it looks just like my carb. I was right, it's not the brass plug but I just had to be sure. -

[John Phoenix]

Krat - I found this on the screws that need to be slotted -

Looking at my carb I do have slot-less screws that hold on the float bowl but I seem to have slotted screws everywhere else. These slot-less screws are even raised up off the surface in a cone shape so they give me plenty of material to get a tool into to make a slot! Awesome. (not sure I need to take off the float bowl at this time unless I decide to clean it)

[John Phoenix]

Originally Posted by JerryHawk250

Check that you don't have any vacuum lines unplugged or cracked. A vacuum leak will cause a leak condition.

There is one port on the bottom of the float bowl next to the hose that allows you to drain the gas from the bowl that is not plugged nor had a hose on it. I assume this is on purpose? I don't see how I could have lost any hoses as everything else is pristine on the bike. I'd have to look at a break down of the carb's parts if I can find one. Easily seen in my video above next to the brass plug there is a 90 degree hose attached to a carb port that is cut at an angle after the bend and just left there. There is no plug at the end of this hose. I also assume this was done from the factory. Other than that, all hoses seem new and intact.

[John Phoenix]

I didn't have a drill but used an awl from a Swiss army knife to make a pilot hole then used a screw eye to bite into and remove the plug. This worked well because I had to get pliers on the screw eye head to turn it.

I still cannot get the bike to stay running no matter how many videos I see on adjusting the fuel screw and idle settings. Later today after some sleep I aim to take the carb back off and slot out the screws to access the jets for cleaning.

[John Phoenix]

Bluewing Lives!

I think it runs better than it ran from the factory. I had no drill or grinding wheel. Trying to use a hack saw on the cone shaped breakaway plugs on the float bowl wasn't working, I couldn't keep the saw in the middle due to the point, it would just slide off. What worked was using a center punch to make a line of 4 holes next to each other in the screw. This gave me a groove to allow the hack saw to create the slots.

I could not see light through the idle jet. The main jet was clear. Carb cleaner would not work. I tried using a straight pin to ream the gunk out and it would not budge. On advice from a video I heated up the idle jet with a cigarette lighter and reamed it again with the pin as well as using carb cleaner. I did this several times. I didn't notice any gunk actually coming out but it must have at one point because I was able to see light through the hole finally. That hole is Teny Tiny! I found out the very tip of the straight pin was the only thing that went through the hole from either side, it would not accommodate the whole circumference of the pin. It does not seem like that tiny hole would allow enough gas to keep the bike idling but it must be the case.

I did not know where to set the idle speed screw but I knew if it was too low the bike would not run so I opened it a good bit. I started with the fuel/air mixture all the way in (to the right) then turned it two full rotations to the left. The bike not only started but to my surprise it kept running!! After it started to warm up a bit the idle increased. so I turned it down some. Just at the point where it wanted to bog again I decreased the fuel mixture back toward the right again, and after a minute or two had to back down the idle speed screw some more. I did this several times so the fuel mixture is somewhere between one and and a quarter and one and a half turns I think. The fuel mixture and or idle speed screw may still not be set right and or the jets may not be the right size (I don't have an ear for these things) but on my test rude the bike ran well enough. No hesitation at the stop signs and it seems to have good acceleration when I hit the gas. I relate all these details in case it will help someone else. Not even sure I adjusted the fuel air mixture and idle speed right according to how it Should be done but that worked for me. Thank you folks!