YY250T suspect fuel issues By cranky68 (Read 1,943 times)

[cranky68]

Hello all. I am new to this site but am glad I found you.

Here is my dilemma. I bought a Shanghai JMsport YY250T two years ago. I had some overheat issues. I have had some wire burn issues. I have had some battery recharge/alternator issues. It has been in the garage for the past year or so without being ridden. I removed some fairings on it recently to chase suspected wire issues. The coolant fan needs to be replaced because the wire harness insulation has melted. I took care of that issue with electrical tape as a pacifier for now. The main problem is that it will not start. I replaced the spark plug and inspected the fire; it has good spark. I then put new gas in the tank (there may have been a little over a quart in it while not being ridden). I disconnected the fuel line at the exit side of the pump and tried to turn the engine over. Fuel squirted out which tells me the pump is working correctly. I then removed the spark plug and poured about a shot glass in the cylinder and then replaced the plug and turned it over again. It started and ran for a second or two, long enough to burn through all of the fuel in the cylinder.

Does anyone sell a carburetor repair kit for a pd30j carburetor? Is there something else I should check before I suspect a dirty carburetor?

[richardthescooter2]

Does this scoot have the air / fuel mix screw on carb, try this turn a/f screw all the way in til it stops, turn out 2 1/2 turns out, then try to start.

[Bashan]

If my Fashion sits for very long the carb bowl dries out and it takes forever to get it started by cranking. If you can get some gas into the supply line and fill the carb it may start. That's all it may need since the pump is working. Rich

[rob63]

Quickest option is take the carb off, pop the float bowl off, whip the jets out and check they`re clear. My money is on the primary being blocked.

[Alleyoop]

+10 Rob63, the scoot has been sitting for so long the Pilot Jet and passage are clogged. Also how about your ENRICHER take it off and see if it is RETRACTED I am betting it is but the Tiny fuel outlets by the BUTTERFLY are CLOGGED and even fuel from the ENRICHER is not getting out.
So I would take the Carb off and take the jets out and make sure you can see DAYLIGHT through them and then SPRAY into the Jet holes and SPRAY should come out by the PILOT JETL tiny holes like in the pictures here:
Alleyoop

[cranky68]

Wow! I was not sure what to think of this site. You "guys" responded very quickly. Thank you. I plan on working on the bike this weekend. I will let you know how things went. Again, thank you all. Very impressed.

[cranky68]

OK. I cleaned the carb, blew out all of the jets. It will only start if I prime it by pouring gasoline into the cylander. It will not idle but does run rather smoothly. Are there factory presets for the jet adjustments?

[cranky68]

richardthescooter2, in your post you mentioned the air/fuel mixture screw, where is it located on the carb? Do you have a picture?

[mike6736]

Yuppers, it sounds like fuel mixture and idle adjustment now. Turn the fuel mixture screw totally in and than 2 1/2 turns out and adjust as need from there that is if you removed and totally cleaned the carb.

Magoo

[cranky68]

Thanks Magoo,
Do you have a picture of the air/fuel mixture screw? Or where, in relation to other componenets on the carb, I could find it?

[Cruiser]

Here is a tutorial on the carb:

scooterdoc.proboards.com/index.cgi?board=intake&action=display&thread=1395

The right hand picture shows the location of the idle mixture screw. The one pictured is a horizontal screw that many 150cc carbs have. The screw for most 250cc carbs is vertical and is facing down between the engine and the carb. This makes it sort of difficult to adjust while the carb is mounted on the engine. A good starting point is to turn the mixture screw clockwise until it just seats and then turn counterclockwise 2 1/2 turns. This is a good ball park setting and should allow the engine to idle so that it can be fine tuned.

[Alleyoop]

This is what your carb probably looks like I labled the parts on it: You can see where the Fuel Ratio Mixture screw is at.
Alleyoop

[mike6736]

That Silly Rabbit has piture of very thing!!!

Magoo