150cc main jet sizes By new2scooters (Read 1,086 times)

[new2scooters]

On my 150, my main jet is marked 105. I have seen a recommendation by some of the vendors on here to upgrade the main jet 1 size when going to a performance dc cdi. How are the jets sized? Is a 110 considered one size up from a 105?

Thanks

[Alleyoop]

You can get 107 main jet,
Quesiton are you sure you have a DC CDI and NOT a AC CDI? What a performance CDI does is ADVANCE your timing.

I did find 108s:

www.jetsrus.com/a_jets_by_carburetor_type/jets_keihin_99101-393_main_round_28-xxx.htm

Alleyoop

[new2scooters]

Mar 6, 2013 21:06:02 GMT -6 Alleyoop said:

You can get 107 main jet,
Quesiton are you sure you have a DC CDI and NOT a AC CDI? What a performance CDI does is ADVANCE your timing.
Alleyoop

I'm 99% sure it is a DC. CDI has 2 plugs, one with 3 wires and one with 1 wire. As soon as I get it back together I'll take a voltage reading off of the 1 wire plug. With key on and engine off, I would expect to find ~12v dc on the 1 wire plug if it is a dc cdi.
Thanks

[Alleyoop]

Yes, that is the way to make sure it is a DC CDI.
Alleyoop

[new2scooters]

Mar 6, 2013 21:06:02 GMT -6 Alleyoop said:

You can get 107 main jet,
Quesiton are you sure you have a DC CDI and NOT a AC CDI? What a performance CDI does is ADVANCE your timing.

I did find 108s:

www.jetsrus.com/a_jets_by_carburetor_type/jets_keihin_99101-393_main_round_28-xxx.htm

Alleyoop

Thanks Alley. I ordered a set of jets that include 108, 110, and 112 from KidNme. That should pretty much take care of me for now. The set with shipping was $19.80. They weren't the cheapest but I ordered from them only because they are a supporter of this forum...I for one certainly appreciate all of the effort you put into this information database. I would be lost without it. Thanks again.
Bill