Author Topic: XR 250 Won't run without choke on??  (Read 1508 times)

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Offline Kenneth S (222)

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XR 250 Won't run without choke on??
« on: August 11, 2013, 06:47:00 AM »
Hi Guys,
I'm restoring an old XR250 and yesterday got it started. My experience with 4 strokes is next to nothing so need some help sorting it. I've given the carb a thorough clean and it has a new Unipod air filter. The bike starts pretty easy with the choke on but after warmin the motor up for a couple on minutes, as soon as I turn the choke off it dies in the ass. What does that mean? Are the jets too small so it needs the air restriction to get the mixture right?
Kenneth S
Go For It

Heaven VMX Club - Racing No 222 - 79 CR250RZ - 84 CR250RE (Steam Train) - 89 CR250RK

Race Bike History
76 RM125A, 77 RM125B, 78 RM125C, RM400C, 79 CR250RZ, 80 YZ250G, 81 RM465X, 82-83 RM490 Frank Pons Special(Beetle's 81 Race Bike)

Offline bazza

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Re: XR 250 Won't run without choke on??
« Reply #1 on: August 11, 2013, 07:57:00 AM »
bit lean or air leak
Once you go black  you will never go back - allblacks
Maico - B44 -1976 CR250- 66 Mustang YZF450,RM250
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Offline head

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Re: XR 250 Won't run without choke on??
« Reply #2 on: August 11, 2013, 08:25:45 AM »
Pilot jet blocked

Offline oldyzman

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Re: XR 250 Won't run without choke on??
« Reply #3 on: August 11, 2013, 09:20:57 AM »
 DIDO
Blocked Pilot
I have a soft spot japanese mxers with aluminium tanks. Two stroke classic Dirt Track...

Offline evo550

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Re: XR 250 Won't run without choke on??
« Reply #4 on: August 11, 2013, 12:03:08 PM »
Air screw setting?

Offline crossedup2

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Re: XR 250 Won't run without choke on??
« Reply #5 on: August 16, 2013, 12:25:41 PM »
Blocked Pilot Jet!! Some of the XR's blocked up in the tube leading to the inlet and are not easily cleared. The jet itself may/will appear clear!

Ultrasonic cleaners sometimes cleared the tube. Goodluck.

Peter B
Anything Yamaha. AT1, CT1 (X3), RT1, DT3 (x3), YZ125X,  YZ250E, YZ400D, IT175E, IT250H, XR500RC . Always looking for Pre 78 Yamaha stuff....