2007 YZ250F

2007 Yamaha YZ250F

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2007 Yamaha YZ250F


YZ250Fw parts list and exploded diagrams
Valve clearances:
Exhaust 0.17 – 0.22mm (0.0067 – 0.0087″)
Dec2017: L 0.203mm, R 0.178mm
Jun2018: L 0.203mm, R 0.178+mm
Dec2018: L 0.178mm, R 0.178mm
Shims: L 1.72mm, R 1.75mm
New Shims: L 1.70mm, R 1.73mm
Jan2019: L 0.203mm, R 0.178+mm
Jan2020: L >0.178mm, R >0.178mm
Mar2021: L >0.203mm, R 0.203mm

Intake 0.10 – 0.15mm (0.0039 – 0.0059″)
Dec2017: L 0.102mm, M 0.102mm, R 0.127mm
Jun2018: L 0.127mm, M 0.127mm, R 0.127mm
Dec2018: L 0.102mm, M 0.127mm, R 0.127mm
Shims: L 1.76mm, M 1.73mm, R 1.72mm
New Shims: L 1.72mm, M 1.72mm, R 1.70mm
Jan2019: L 0.152mm, M 0.127mm, R 0.152
Jan2020: L >0.127mm, M 0.127mm, R >0.127mm
Mar2021: L >0.127mm, M 0.127mm, R >0.127mm

Aug 18: Backed off pilot air screw ~1/4 turn to address hanging idle and tough warm starts (although we weren’t following the procedure in the manual)

May 2020: Unscrewed pilot air screw a little ~1/16 turn due to a bit of popping on decel.

To Do List

  • New front brake pads?
  • Replace upper rear shock bearing – got a set of bearings but there isn’t much play at all, probably install them next winter

Completed Tasks

January 2020

  • Check valve clearances

June 2019

  • Replace broken ASV clutch lever screw – Josh picked one up from TSR

Feb 2019

  • Oil and filter change – AMSOIL synthetic

Jan 2019

  • Re-fill with coolant
  • Install new head gasket
  • Check piston and con rod, visually inspect crank – looks good
  • Check valve clearances
  • Repacked muffler

Before 2019

3 replies on “2007 Yamaha YZ250F”

Before removing the forks to change the fork seals, it is best to loosen the cap on top. On these forks that requires a special tool, a large octagonal wrench. These can be bought for about $30 but I was convinced that I could design a tool that could be 3D printed. After a couple of iterations and several hours of printing, the tool in the pic worked a treat! Both caps are now loose and the forks are ready to be removed.

First time out at the track I had the lad ride the 4 stroke as I figured the smooth power delivery would be easier for him to cope with. He did excellent, only had one little fall in a corner and was soon hitting some decent jumps. When he tried the 125 SX on the next outing, he came back with a huge smile on his face and said “I want to ride this, we’re trading”! I rode the 125 SX exclusively on the first outing, and loved it, I wasn’t overly keen on even trying the 4 stroke but after a couple of laps on it I was sold! The YZ250F handles great and gives confidence over the jumps with the smooth power, vastly superior to the old 2001 YZ250F I had. There is a harsh double on one section that I daren’t attempt on the SX but after a couple of laps on the YZ, I went for it and cleared it no problem! The only bit of concern now is the reliability, the experience with the 2001 dropping a valve has shaken my confidence. It sounds a bit rattly to me especially when you shut off the throttle but I’m not sure what is ‘normal’ for these.

Out at the track again yesterday, bike ran great! Only minor thing was that the gear shift lever worked loose – same on the KX100 weirdly?? Oh also the front end washed out a couple of times but I think that was rider error.
I was nailing some of the jumps and doubles but still jibbing out on the big ones. The old RXR inflatable body armour I picked up was nice and comfy, not too bulky.

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