Carb jet adjustments By cranky68 (Read 727 times)

[cranky68]

Jemstar 250cc (carb jet location pictures attached)

I cannot seem to get my scooter to start without pouring gas into the cylinder. I would prefer to not go through all of that trouble just to go for a Sunday ride. Inside the float chamber there are three separate jets. How do I know they are adjusted properly? I cleaned the carb a while back and did not note how many turns in/out the jets were to begin with.

The scooter started well before I messed with the carb. I felt it needed to be cleaned because the scooter ran a little rough.

Attachments:

[Alleyoop]

Turn the fuel ratio mixture Clockwise until it stops and COUNT THE TURNS. Then turn it out Counter Clockwise 2 1/2 turns. From there only minor adjustmensts should be needed if at all.
Alleyoop

[Bashan]

Inside the float bowl you have the main jet and the low speed jet. They are not adjustable in the bowl except by replacing them with different sized jets. If the scooter ran well with the same jets it should again once you set your A/F as Alley described. If you're having to pour gas in to start it I'd check your auto-choke and also set your valve gap.

[cranky68]

I ran a test on my auto-choke and I believe it is bad. PLease look at the attached pictures and let me know if it looks like the auto-choke is operating properly. The manual said that the tipo should extent 3-6mm but it looks to me like the "base" extened not the needle tip. Could this cause a scooter to not start?

Attachments:

[Alleyoop]

It is stuck in the EXTENDED POSITION that is why it is hard to start and not getting extra fuel for starting. Get a new one. It should be RETRACTED to feed it fuel for starting then when 3-4 minutes or so it should EXTEND out like in your picture to cut off the extra fuel.
Alleyoop

[cranky68]

Excellent! Thank you very much. Where could I find a new one?

[Alleyoop]

www.buggypartsnw.com/home?page=shop.browse&category_id=14