1p39qmb 50mm bore jet size?

SirYes · 09-06-2013, 11:00 PM

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 · 09-07-2013, 12:10 AM

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/4129...jet-set-gy6-50

SirYes · 09-09-2013, 10:22 AM

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

blueboy5000 · 09-14-2013, 09:22 AM

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 · 09-14-2013, 12:15 PM

Quote:

Originally Posted by 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

intake port on my head is bigger than a quarter same goes for the exhaust side.

SirYes · 09-14-2013, 02:16 PM

SirYes · 09-27-2013, 10:17 PM

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 · 09-27-2013, 11:37 PM

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 · 09-28-2013, 12:50 AM

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

skuttadawg · 09-28-2013, 01:17 AM

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-...ategory=133078

f4milytime · 09-28-2013, 11:54 AM

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

SirYes · 10-14-2013, 12:19 PM

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 · 10-14-2013, 05:12 PM

also run mine at 95 and its perfect

SirYes · 10-19-2013, 11:48 AM

SirYes · 03-03-2014, 02:20 PM

09-14-2013, 09:22 AM	#4
blueboy5000 Join Date: Jul 2011 Location: Connecticut Posts: 493	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 __________________ 2011 Roketa MC-23-150 4T 150cc 157 qmj 24mm carb w 115 main jet and paper cone air filter Manual petcock w Tygon fuel lines Scrappy Dog Scooters Retro-slash stainless straight-thru exhaust RED spring clutch Adjustable CDI (brand unknown, it's blue and red and works great!) KOSO high performance variator w 12g sliders Gates Powerlink 835-20-30 belt GPS verified 65mph on flats.
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09-07-2013, 12:10 AM	#2
skuttadawg Join Date: Jul 2011 Posts: 127	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/4129...jet-set-gy6-50
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09-14-2013, 02:16 PM	#6
SirYes Join Date: Jul 2013 Posts: 44
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09-27-2013, 10:17 PM	#7
SirYes Join Date: Jul 2013 Posts: 44	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.
	0

09-27-2013, 11:37 PM	#8
skuttadawg Join Date: Jul 2011 Posts: 127	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
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09-28-2013, 12:50 AM	#9
SirYes Join Date: Jul 2013 Posts: 44	yeah this guy is using the spacer just made the hole bigger
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09-28-2013, 01:17 AM	#10
skuttadawg Join Date: Jul 2011 Posts: 127	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-...ategory=133078
	0

09-28-2013, 11:54 AM	#11
f4milytime Join Date: Sep 2013 Location: The Valley Isle, Hi. Posts: 3	I run a 95 main, with an 18mm carb. Does well so far....Alohaz
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10-14-2013, 12:19 PM	#12
SirYes Join Date: Jul 2013 Posts: 44	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.
	0

10-14-2013, 05:12 PM	#13
venxxxxx Join Date: Sep 2013 Posts: 20	also run mine at 95 and its perfect
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10-19-2013, 11:48 AM	#14
SirYes Join Date: Jul 2013 Posts: 44
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03-03-2014, 02:20 PM	#15
SirYes Join Date: Jul 2013 Posts: 44
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