WR426 overheating after cam retard for YZ timing

Hi Guys,

I brought this bike a month ago and was running well old owner couldn't tell me if the valves had been checked, So i took the cover off and checked the valve clearances and got them to spec, now i retarded the exhaust tooth by 1 tooth put it all back together and she fired up on 2nd kick (Still getting used to De compressor) pretty hot day like 37 degrees and i was in the garage so more like 40's anyway i let it idle for a while then gave it a few squirts to check there was no back firing etc. then i noticed she was overheating within 5 mins roughly

i have attached picture of what i think is the right cam settings.


sorry guys the first picture is what i have set it at the 2nd picture should be stock wr timing correct? and the 3rd picture is how it was set before i touched it

Please give some feedback i think that the cam chain may be stretched but then again ive heard the yamy mechs were a lil lazy with the punch marks on the 01 wr 426's

all picture are at TDC with cam lobes facing out of course,

Thanks guys look forward to your response

I forgot to mention I had to put oil in bike prior to starting as silly me left the plug to rotate to TDC out over night and found a puddle on the floor

Started bike 1St kick today the header pipe started to get hot in less than 30 second think I'm going to put it back to how out was when I first pulled the cover off


I have an 06 450 so i could be wrong here but compared to my bike it looks to me like:

pic 1 both cams are retarded a tooth or your not on tdc but on the timing mark at the crank. it will move around a little.

pic 2 looks correct

pic 3 looks like the intake cam is retarded 1 tooth.

make sure its not on the timing mark but on actual tdc. you might have to hold it there because i have seen them rotate a little when you let go of the wrench. its normal for the exhaust header to glow a little when just sitting in the garage not moving.

let me know what you find. p.s. its -14C here and lots of snow so no riding... wish i was there

Hi Swolf,

Definitely on TDC there is a HI on the flywheel and instructions are to be on the I and also have checked the piston height with a screwdriver/ straw ect.

I changed it back to the way it was when i first pulled it off i keep you guys updated.

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