2006 YZ250F Big Bore Jetting Problems

braaap_man
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braaap_man
Edited Date/Time 10/10/2019 9:42am
Hey everyone, got a really disgusting bog going on with the bike since I put an Athena 270cc kit on it. It bogs like a mf on every single gear and wants to die if it's not choked. My current setup is (before kit) Main - 180, Pilot - 45, Leak - 50, Auxiliary - 72, Needle is 3 from the top, Air Screw was 2 turns and a quarter out, and the Boyesen QuikShot thing was at 1 turn and 1/8. Any comment or feedback would be greatly appreciated, I’m not getting Dad’s help anymore haha, and the race is this weekend 🤦🏽‍♀️ thanks in advance for the help 🤙🏽
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Paw Paw 271
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Paw Paw 271 10/9/2019 7:03pm
10/9/2019 7:03pm
Accelerator pump working correctly?
Have you tried changing the accelerator pump timing?
Is the spray hitting the slide?

Paw Paw
1
braaap_man
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braaap_man 10/9/2019 7:13pm
10/9/2019 7:13pm
Paw Paw 271 wrote:
Accelerator pump working correctly?
Have you tried changing the accelerator pump timing?
Is the spray hitting the slide?

Paw Paw
I’m not gonna lie, I’m actually confused as to where and what it is lol. As far as I know, I know gas is getting where it’s supposed to and the mechanic installed everything right...so, please educate me
braaap_man
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braaap_man 10/9/2019 7:26pm
10/9/2019 7:26pm
Radfonz wrote:
blocked pilot jet
Could it be? I always empty the carb whenever the bike is gonna sit for a long time but it could be that, I’m thinking it’s a little on the rich side but I’m 100% sure on that yet.

The Shop

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garagedog
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garagedog 10/9/2019 9:47pm
10/9/2019 9:47pm
With the Quickshot, isn’t the Leakjet supposed to be blocked in the float bowl?

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Paul_Pitzonka
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Paul_Pitzonka 10/10/2019 5:26am
10/10/2019 5:26am Edited Date/Time 10/10/2019 9:23am
Stock Leak jet should be plugged off... plugged squirt nozzles possibly...As mentioned above incorrect accelerator pump timing... I’ve also ran into an issue one time while using a boyesen quick shot where regardless of the needle adjustment position it was flooding the bike and causing the same symptoms (never figured out why assuming machining error on the circuit in the accelerator pump cover) replaced it with another one cured the problem... Adjusting squirt timing is fairly simple, if you have a slow motion camera function on your phone it helps an incredible amount... take the carb off and fill the bowl with fuel... (There is an Adjustable screw for the accelerator pump under the side cover) Look down the back of the carb throat from the airbox side... open the throttle to full throttle quickly as you would while riding... note when the fuel shoots out of the squirt in correlation to throttle position... it should be just missing the slide as it begins to open... adjust as necessary
braaap_man
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braaap_man 10/10/2019 8:44am
10/10/2019 8:44am
garagedog wrote:
With the Quickshot, isn’t the Leakjet supposed to be blocked in the float bowl?

I’m not sure, I never experienced any bog or removed a leakjet...
braaap_man
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braaap_man 10/10/2019 8:45am
10/10/2019 8:45am
Paul_Pitzonka wrote:
Stock Leak jet should be plugged off... plugged squirt nozzles possibly...As mentioned above incorrect accelerator pump timing... I’ve also ran into an issue one time while...
Stock Leak jet should be plugged off... plugged squirt nozzles possibly...As mentioned above incorrect accelerator pump timing... I’ve also ran into an issue one time while using a boyesen quick shot where regardless of the needle adjustment position it was flooding the bike and causing the same symptoms (never figured out why assuming machining error on the circuit in the accelerator pump cover) replaced it with another one cured the problem... Adjusting squirt timing is fairly simple, if you have a slow motion camera function on your phone it helps an incredible amount... take the carb off and fill the bowl with fuel... (There is an Adjustable screw for the accelerator pump under the side cover) Look down the back of the carb throat from the airbox side... open the throttle to full throttle quickly as you would while riding... note when the fuel shoots out of the squirt in correlation to throttle position... it should be just missing the slide as it begins to open... adjust as necessary
Hmmm I’ll try that out, thanks man 🙏🏽 I’ll keep it updated
DynoDan22
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DynoDan22 10/10/2019 9:42am
10/10/2019 9:42am
Make sure the carb slide cutout plate isn't installed upside down. I've seen this stump many people. If installed incorrectly, the bike will barely run and pop etc. Its easy to check by pulling the rear carb boot off and looking into the throat. the cutaway should be on the bottom not the top. I don't know if you had the carb apart or the slide out, but if so, double check this. good luck!

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