2019 YZ250 oem jetting specs ?

H4L
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1/11/2020 9:16am Edited Date/Time 1/28/2020 1:25pm
Looking for the oem jetting specs on a 19 YZ250. Thnxz..
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hubbardmx50
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1/18/2020 4:24pm
H4L, I thought you were a red bleeder!? Lol! Jk
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H4L
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1/18/2020 5:59pm
H4L, I thought you were a red bleeder!? Lol! Jk
Last time I cut myself I did bleed red. Haha
Picked up an older AF YZ2 to flip that has updated jetting specs, but runs like crap.
Trying to sort it out.
FGR01
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1/18/2020 6:05pm
Pretty much all YZ250 2007 and newer are 178main, 50 pilot, and N3EW needle. 1999 to 2006 the leaner N3EJ needle was standard and it came with the N3EW as an optional needle which people used when the bike would ping on pump gas.

If you put in this jetting (either needle) and run 32:1, the bike should run reasonably well. If it doesn't you have other problems. You'll sometimes see YZ250's with much leaner jetting like 162-165 main and 45 pilot from guys who are either slow woods riders, at elevation, or running lower oil ratios like 50:1.
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H4L
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1/18/2020 6:51pm
FGR01 wrote:
Pretty much all YZ250 2007 and newer are 178main, 50 pilot, and N3EW needle. 1999 to 2006 the leaner N3EJ needle was standard and it came...
Pretty much all YZ250 2007 and newer are 178main, 50 pilot, and N3EW needle. 1999 to 2006 the leaner N3EJ needle was standard and it came with the N3EW as an optional needle which people used when the bike would ping on pump gas.

If you put in this jetting (either needle) and run 32:1, the bike should run reasonably well. If it doesn't you have other problems. You'll sometimes see YZ250's with much leaner jetting like 162-165 main and 45 pilot from guys who are either slow woods riders, at elevation, or running lower oil ratios like 50:1.
Thnxz for the info..
I haven’t had a chance to open up the carb yet, but it is running lean. Hoping to get it done next weekend.
hubbardmx50
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1/18/2020 8:01pm
Nice, I flipped a 2001 Yz250 last year and made some money.
15tc150
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1/26/2020 1:21pm
Check the slow jet as well, should be a #55 stock, but they did come with two sizes of slowjets in the factory jetting kit that gets sold with new yz250's
FGR01
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1/27/2020 5:59pm
15tc150 wrote:
Check the slow jet as well, should be a #55 stock, but they did come with two sizes of slowjets in the factory jetting kit that...
Check the slow jet as well, should be a #55 stock, but they did come with two sizes of slowjets in the factory jetting kit that gets sold with new yz250's
50 pilot is stock in the USA. Maybe 55 is stock in Canada ?
15tc150
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1/27/2020 6:11pm
15tc150 wrote:
Check the slow jet as well, should be a #55 stock, but they did come with two sizes of slowjets in the factory jetting kit that...
Check the slow jet as well, should be a #55 stock, but they did come with two sizes of slowjets in the factory jetting kit that gets sold with new yz250's
FGR01 wrote:
50 pilot is stock in the USA. Maybe 55 is stock in Canada ?
No, pilot jet 50 stock, slow jet it the teeeny little guy to the right of the carb bowl, and controls the flow that comes through the electronic boost jet, 55 is stock, but they do come with a 50 and 45 slow jets as well
FGR01
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1/28/2020 1:25pm
15tc150 wrote:
Check the slow jet as well, should be a #55 stock, but they did come with two sizes of slowjets in the factory jetting kit that...
Check the slow jet as well, should be a #55 stock, but they did come with two sizes of slowjets in the factory jetting kit that gets sold with new yz250's
FGR01 wrote:
50 pilot is stock in the USA. Maybe 55 is stock in Canada ?
15tc150 wrote:
No, pilot jet 50 stock, slow jet it the teeeny little guy to the right of the carb bowl, and controls the flow that comes through...
No, pilot jet 50 stock, slow jet it the teeeny little guy to the right of the carb bowl, and controls the flow that comes through the electronic boost jet, 55 is stock, but they do come with a 50 and 45 slow jets as well
Ahhh... we've got a difference in terminology here. What you are calling the slow jet is called the power jet here in the USA.

Also, here in the USA the term "slow jet" is a synonym for the pilot jet.

Also, here in the USA, the power jet, or what you are calling the slow jet, is also a size 50 stock. Not sure about Canada.


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