Retarding the Timing Chain

[firefighterjosh]

My buddy just bought a used YFZ. We are going to retard the exhaulst timing 1 tooth, but we are not sure if it is already done. How can we tell? Is there a easy way without taking the head off? He was neck and neck with a 450r that had a HRC kit and LRD Exhaulst. The 450 was jetted for the HRC but not for the exhaulst added on.

You dont have to take the head off to to do the cam mod... Just the cam cover.

This might help with what the stock timing is..
http://www.yfzcentral.com/reviews/exhaust_cam/8.jpg

and heres a hole a page on the Cammod.. http://www.yfzcentral.com/cammod.htm

[firefighterjosh]

Thanks for the post. I ment to say cam cover. The owner said he never touched anything but the exhaulst. Also do we need to rejet? I didn't see anything in any articles saying to rejet.

[gixer_boy99]

To check and see if the mod has been dont take off the valve cover and count the number of pins in the chain. Stock should be 14 if the mod has been done there should be 13. If you do the mod the cam bolt torque to 6 ftlbs. No you dont have to rejet it..

[firefighterjosh]

We just did it yesteday. But it has been raining all day and all night so he hasn;t had a chance to test it. grrr Does this help tourqe or top end or both? I am kind new to the 450 era

[gixer_boy99]

Im not sure on that. I thought it only made it rev faster. but what do I know.

[Toadz400]

You should've torqued the bolts down to 7.2 ft-lbs.

The cam mod gives a gain in power in the mid-top range but does not take away any low end.

[firefighterjosh]

Everything was done correctly. He race my buddies 450r again. ( I out it in my first reply)

Stock he race the 450r and they were neck and neck and the 450r would pull maybe 1pmh on topend

Now they race and they are neck and neck but now the YFZ pull 1mph.

[Hondarider440ex]

i wouldnt retard the timing cause i did it and on the front of the motor a plug blew out and oil went everywhere and almost blew it up they said it built up compresion and the plug blew out and it doesnt change that much anyway

[GPracer2500]

Originally posted by Hondarider440ex
i wouldnt retard the timing cause i did it and on the front of the motor a plug blew out and oil went everywhere and almost blew it up they said it built up compresion and the plug blew out and it doesnt change that much anyway

That plug blowing out had nothing to do with the cam mod. There are billet plugs available to cure that issue.

[Toadz400]

Originally posted by Hondarider440ex
i wouldnt retard the timing cause i did it and on the front of the motor a plug blew out and oil went everywhere and almost blew it up they said it built up compresion and the plug blew out and it doesnt change that much anyway

GPRacer2500 is correct, the cam mod has absolutely nothing to do with that POS plastic plug blowing out. It will eventually do it no matter what you have done to your engine, it's just a disaster waiting to happen. Everyone who has an '04 should get the billet plug before they even ride it. Just make sure to have it torqued down properly, a friend of mine had his done by the dealership and his plug popped out 20 miles away from our trucks...