1p39qmb 50mm bore jet size?

[SirYes]

I have a 1p39qmb and a 50mm bore kit and a ported head 69mm valves 22mm carb 150cc intake manifold ported. but don't know what jet size to use.

[skuttadawg]

No exact answer and results vary like climate , altitude , exhaust and if you modded the airbox or installed a Uni or K&N . I used a 95 MJ with my 50mm BBK since I live near mountains and its so darn humid .

I would get a jet kit instead of paying per jet price . PFS has one but their site seems to be down at the moment . Here is another source for a jet kit http://enviromoto.ecrater.com/p/4129835/naraku-main-jet-set-gy6-50

[SirYes]

using the stock airbox with the black part of the stock filter use 98 jet 44mm bore

[blueboy5000]

22mm is probably a bit very large for that set up, I use a 19mm carb w #94 main #38 pilot, standard intake and cone-paper filter on my 50mm BBK

[SirYes]

22mm is probably a bit very large for that set up, I use a 19mm carb w #94 main #38 pilot, standard intake and cone-paper filter on my 50mm BBK
intake port on my head is bigger than a quarter same goes for the exhaust side.

[SirYes]

https://mail.google.com/mail/?ui=2&ik=a29a64da21&view=att&th=1411d8bdd349de74&attid=0.2&disp=thd&realattid=1446175219378027786-local1&zw https://mail.google.com/mail/?ui=2&ik=a29a64da21&view=att&th=1411d8bdd349de74&attid=0.1&disp=thd&realattid=1446175219378027786-local0&zw

[SirYes]

well i but the kit on ran a 40 idel jet main jet drilled that sh#t out 1.20mm was to big 1.00mm didnt even try it to small. drill bits from manards tryed a 55# that they had and it works some what needs to be a bit bigger.

[skuttadawg]

Did you use the spacer on the intake ? A buddy built a 50mm with large valve and ported head but used a 24mm without the intake spacer , Uni and a performance exhaust .

Jetting is a trial and error series of testing but once you get it dialed in well worth it .

If you have the cabbage you can go with EFI www.ecotrons.com

[SirYes]

yeah this guy is using the spacer just made the hole bigger

[skuttadawg]

Here is a cheaper jet kit that work on the 22m but if not they have on for the GY6 as well http://www.partsforscooters.com/114-49-QMB139-Main-Jet-Kit?sc=34&category=133078

[f4milytime]

I run a 95 main, with an 18mm carb. Does well so far....Alohaz

[SirYes]

looking for more top end some where around 70 to 75 and putting in a cam. just not share witch gear to run with 10" tire at some point will go bigger rim and tire just not now.

[venxxxxx]

also run mine at 95 and its perfect

[SirYes]

https://www.youtube.com/watch?v=fElPPzGiVH0

[SirYes]

http://www.youtube.com/watch?v=wpgzlqfQN5I&feature=youtu.be

[SirYes]

this video has the stock variator with rollers so yes it can go faster in top end.