Need timing degrees on yz cams

9 replies to this topic
  • ready fredy

Posted August 14, 2008 - 03:47 PM


Im having trouble getting my timing and need actuall open degrees on a 450 wr or yz ill degree it and then make solid marks to end this night mare 4 ever. I searched for hours and cant find actuall timing degrees for the cams pls help!!!!!!!!!!

  • tweav

Posted August 15, 2008 - 03:19 AM


what are you trying to do ? you do know that the timing gears are fixed on these cams ,and the cam flip trick does not work on a 450, because of the automatic decompression pin location is also fixed timing. What nightmare?

  • ready fredy

Posted August 15, 2008 - 05:25 AM


I am using the tfz cam here and some posts say that the marks on the new cam are usless on the old 400-426 heads and even the timing marks on the factory cams arent even spot on for exact accurate installation either. But on the other hand i have read posts that on the yfz450 some people have changed the timing and had no troubles. With kick start i dont think there is the same reprocussions as with the happy button. I want exact openg in degrees so i can use a degree wheel and set the cams on the first try i hate and i repeat hate have to do something twice coz of innacuracys on the gears after degreeing ill mark the gears and never have this issue again!!!!!!!!

  • tweav

Posted August 15, 2008 - 06:06 AM


I've never seen it posted anywhere the degrees , lift and duration of any of the wr or yz cams , it must be top secret . I've also seen nothing on the graves cams

I did find this info on the hot cams for 2003 + 450

Exhaust lift (mm): 8.67
Exhaust lobe center (degrees): 103
Exhaust duration (degrees at 1mm): 265
Exhaust valve lash (mm): 0.2

Intake lift (mm): 8.86
Intake lobe center (degrees): 110
Intake duration (degrees at 1mm): 269
Intake valve lash (mm): 0.15
Note: Divide mm values by 25.4 for inches

  • ready fredy

Posted August 15, 2008 - 12:43 PM


Wellllll i guess its my mission to get the specs so all of us can rest easyer and totally eliminate cam timing issues 4 ever. And i almost forgot!!!!!! I read some posts where the cam gear slips on the cam shaft further comfusing some of us on performance issues. I am sure my friend will let me take readings from his 426 with yz timing but ill still have to find a donor 450 to take measurements from ill post them for all to read along with instructions for degreeing cams for dummies as i know some are intimidated by this process but its quite simple and very accurate nooo guessing anymore 360 degrees is 360 degrees plain and simple!!!!!!

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • ncampion

Posted August 15, 2008 - 04:58 PM


As tweav said, you cannot "degree" the cams in like in a car engine. The sprokets are fixed to the cam, all you can do is screw up the timing by one whole tooth. I agree that the factory timing marks that are stamped into the sprokets are somethimes not "right on", however I don't think there is appreciable variation in the actual cam timing. if there was, there would be a lot of really poor running bikes out there and people would be screaming at Yamaha. Hot Cams does make adjustable sprokets for their cams, but the stockers are fixed. Cams slipping on the sprokets is very rare, usually associated with a screwup on the part of the user. Just follow the timing instructions as far as the marks are concerned and make sure the "pin" count is correct and you'll be fine.


Posted August 15, 2008 - 09:53 PM


Here is an excellent post regarding the most common mistake made while timing... I made it, more than once :D I could have sworn I had everything set up at TDC... install the chain tensioner and it all went hell :)

This whole thread is actually pretty entertaining :worthy:


  • ncampion

Posted August 16, 2008 - 07:15 AM


One of the best tools I ever made for the WR is to get a bolt the size of the plug for the inspection hole in the flywheel cover. Then when you have TDC perfectly located, just screw the bolt in until it contacts the flywheel, not too tight, but tight enough so that it locks the flywheel in place. With this in place you don't have toworry about the flywheel turning a little when you put the chain over the cam sprokets. It helps if the bolt is ground to a point at the end so it bits into the flhywheel a bit. Cam timing is not magic, just pay attention to the details. If you want a tough tming job, try timing the cams on a 911 Porshce engine where you have to measure valve lift at specific degrees of crank rotation.

  • ready fredy

Posted August 16, 2008 - 08:15 PM


Yes i am very aware that you cannot Degree the cams in what i want to do is post actual opening and closing of the valves so we have a good reference point to go by if we know the timing its supposed to be then we can also accuratly diagnose cam timing probs quickly such as a cam slipping in the gears which can only be found be checking the actual opening of the valves in relationship to the crankshaft that is the only 100% accurate way to find these probs. I dont need lobe center,duration.overlap, Numbers just simple opening and closing degrees from a good running bike with no probs. Example intake opens @ 24 degrees atdc and so forth .........comprendo???????

  • ready fredy

Posted August 16, 2008 - 08:19 PM


Ohhhhh and i almost forgot We need actual vacume measurements at idle this is another way to quickly diagnose valve timing woes also i believe some of these so caled jetting probs can be associated with improper valve timing/vacume probs


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.