BS or what? Doesn't feel like it.
Posted August 12, 2002 - 04:26 PM
Saturday morning I started rounding up the parts to fix it: new head gasket, base gasket and an o-ring. Everything but the base gasket was available. I was able to locate a YZ base gasket about 60 miles away. (Good excuse for a fast road trip on my street bike.) Different part number but it would work. I was told that the YZ gasket increases compression because it's a little thinner and I'd have to run with YZ timing to deal with that. I was already running YZ timing so I figured "no problem".
More compression equals more power, right? Well, it sure did feel like it had more power! Admittedly, conditions on Sunday were nearly ideal due to a cold front that had dropped the humidity and it wasn't too hot. But it ran very strong--better than it ever has as far as I can tell.
Is it my imagination or could the YZ gasket truly be enhancing performance? (I thought WRs and YZs both had a 12.5:1 compression ratio.) If I'd have known about this, I would have replaced the gasket long ago. BTW, the new o-ring fixed the radiator problem.
Posted August 13, 2002 - 03:36 AM
The O-ring is the one that comes out of the front left side of the head. The one you have to remove to get the head off? If so, why did you have to remove the head to change it?
The cometic base gasket is the same between the WR and YZ. And I'd be shocked if the difference between two paper gaskets could be noticed. Could the cooler weather have been the difference you noticed?
Posted August 13, 2002 - 04:52 AM
The temperature was just a little cooler than it has been- about 88° vs 95° F. If the weather did make it run better, I'd bet the lower humidity affected it more than the temperature. But that's what I'm not sure about and it made me wonder if the thinner gasket/higher compression I was told about was BS. I do know it did run better. I drag raced a guy on a very strong running XR650R and while he did pull away from me, it was a good close race and we both reached the same approximate top speed. Bouncing off the rev limiter is an interesting experience.
Posted August 13, 2002 - 06:20 AM
wr 426 has .080" deck height w/stock gasket.
yz gasket .050" deck height.
Posted August 13, 2002 - 04:39 PM
Posted August 14, 2002 - 03:58 AM
Posted August 14, 2002 - 07:55 AM
didn't you do this SFO? -(along with many things)
Posted August 14, 2002 - 09:51 PM
among with some other things...