Timing mark - 01 WR450

[gregghealy]

When the dots on the cam gears are flush with the top of the head, should the cam lobes be at exactly opposite angles at TDC compression?

My buddies bike that I just tore down had the exhaust lobe almost parallell with the head, and the intake out and up about 20 degrees. On my RMZ the lobees should be at opposite angles. I assumed that should be the case for any 4 stroke? Im wondering if this motor didnt jump time.

Wont be able to put it back together till I get shims tomorrow, I guess then Ill know if it was out.

[tom00013]

I just did my valves on a '02 yesterday and I think that when you're looking at the cams from the shifter side you will be able to see the "E" and the "I" letters on the cams and they will be right side up -the exhaust should have one dot visible on the left side of the gear and the intake should have one dot visible on the right side of the gear-the timing mark should be lined up with the "I" on the crank. I think this is right-I checked and double checked by the book before checking the valve clearances and I think this is what I had-on a different note....if the previous owner changed to YZ timing your exhaust cam will be off a little because of moving it one pin closer or further-not sure which. Do a search on timing and yz and you should get tons of info on this.

[gregghealy]

Yep, the exhaust if advanced (or retarted) on tooth. So we could have moved it one tooth like the YZ and made it run stronger without any side effects? Ill start searching...

Thanks!