Help with 50cc gy6 running rich

[cjoslin]

I was wondering if anyone could help me. I'm working on a friends tank 50. It has a walbro carb on it. The scooter only has 24 miles on it but is 2 years old. It is difficult to start. When it does, it usually idles for about 30 seconds and then stops. Then you have to wait a few minutes before trying again or it won't fire. I've adjusted the idle screw and was able to get it to run. However It smokes and also surges badly at top speed. I varified that the feul pump is working and that there is plenty of gas getting to the carb. I basically think it needs the air fuel mixture adjusted. I only see one other screw located on the oposite side of the the throttle/idle side. It has red tamper ink on it.
Is this the mixture adjustment and how should it be done correctly.

thanks, Corey

[Aaron]

Is the gas two years old Corey? If so drain it out and put in fresh... Also the carb sounds like it may be gunked up from sitting. Depending on your comfort level taking apart a carb you can easily remove it and dissasemble it for cleaning blowing out all the orifices and paying close attention to the main jet. Check here www.oregonvintage.com look in the scooter help area. Stan has great pics of Scoot repair issues including a carb. The pics are of a Tank but not a 50... same idea though. Someone will be able to help you sort it out I'm sure..I doubt it's serious.


Aaron

[cjoslin]

Thanks for the feedback. I already drained all the gas out and put in new. I'm very comfortable taking apart the carb. That sounds like the next step before adjusting anything.
I will take a look at stan's site for any additional help. He is really a good person to deal with. I've purchased a bunch of hop up parts from him for 2 UM Matrix 150 scooters.

Thanks,

Corey

[perrym]

Corey, where do you live? Are you in a high altitude or hot climate? Did you replace the spark plug with an NGK CR7HSA and gap it to .040"? Change the spark plug first and gap it. If it's still doing bogging, then remove the snorkel from inside the airbox. The air mixture screw that is on the lower left front of the carb should be backed out 1.5 to 2 turns, you access it from the tranny case side.

[cjoslin]

Thanks for the info. I have changed the plug and ensured it was gapped correctly. Still no luck. I live in Knoxville, TN.
I will try adjusting the air mixture screw as see if that helps. I've also tried unplugging the choke with no luck at all.
The wierd thing about this problem is if it doesn't start, you have to wait for several minutes before trying again or your wasting your time. Almost like it is flooded. I will also disconnect the air intake filter and see if that helps. I've the caarb completely down and cleaned it out. I did'nt find anything alarming. still no luck. I verified spark as well.
I really think the carb is drowning the engine for some reason. Then by waiting several minutes and backing the idle screw all the way out, it will start and idle for about 30 seconds. Then it's dies.

Thanks, I will try your suggestions and let you know. I just have to keep eliminating things.

Corey

[ryan_ott]

Have you pulled the jets out and cleaned them, try blowing air through all the openings to clean it real good. The choke needs to be plugged in or it is on all the time. Have you checked the air tube to see if the filter is clean and no one made a home in there.

[jdikov]

You mau have a cracked block. I had that happen onec with a scoot. Did the same thing, runs 30 seconds or so then quits, can't start it for about 4 mon then it does the same thing.

[cjoslin]

Good news. I got the scoot running well. It was a combination of old gas, poorly adjusted carb, spark plug gap, and a loose coil wire.
Bad news, now the front wheel wants to grab. I can't achieve top speed or go up hills. The wheel will free spin although there is a sqeeking sound. The owner of this scooter put the front wheel on himself.
Does anyone have any suggestions what to look for?

Thanks,
Corey