xr400 gaskets=degree cam???

[beyer05]

i was reading an old thread about the deck height of the cylinder and changing gaskets. I am planning on running no base gasket (sealant only) and an XR400 head gasket. Do I have to re-degree (is this a word?) my cam (curtis sparks cam)? Did anyone do the gasket thing and not re- degree their cam? How do you do it?

[crashinmatt]

well i used a base gasket from cometic, which i guess is supposed to be the thinest u can buy, and a xr400 head gasket and i didnt drgree the cam. i have a WB "track" cam. it runs great. but i couldnt completely tell u about with no base gasket. i hope someone else can help u out.

[beyer05]

Anyone else???

[beyer05]

bump

I have not degreed mine and I have the.012 basew/ .025 head cometics.

I keep hearing that I should since it would advance it back to where it belongs (timing) but I am now looking into a advance key as well.

I guess the theory is that if the timing gets too retarded your loosing some power there. Though I may never get this motor right or finished it is running pretty well with taking the time to degree in the cam, but I would recomend it and may even get it done.

[beyer05]

I called Curtis Sparks and the guy I talked to said changing the gaskets was not enough to worry about and that they don't do it. Maybe he just wanted me off the phone, but I think it will be fine. Also, doesn't the degree key advance the ignition timing, not the valve timing?

[MIKE400EX]

The degree key that is sold by Sparks, and others, advances the ignition/spark timing only - not the valve/cam timing. It does however also advance the timing marks on the flywheel relative to the crankshaft - so don't get fooled there. BTW, a slightly retarded (!?) cam, or ignition, will usually net a little increase in top end torque - and take away a little from the bottom. A thin head gasket and sealant on the base will make a negligible difference, and alot less difference than a worn and/or stretched chain.

[patrick delao]

I put the XR400 cam in my 440EX and there is no adjustment for degreeing the cam so I got a degree wheel and figured about 4 degrees advance is where I wanted to be and also called a couple of shop to get there advice and they said 4 is the max they would go. On the XR cam I had too slot the cam wheel to get my 4 degrees. Advance is more bottom end and retard is for more top end. The sparks degree key is for ignition timing and I had that also and just put the sparks key on my raptor a few weeks ago.
Hope this help
Pat

I tried a .025 head gasket and sealant for a base and my quench area was too small - total of .032. Put in a cometic ss base gasket and got .042 - just about perfect!

Yours may be a little different. I would suggest calling cometic at (800-752-9850) and get a spring steel base gasket that comes with a viton rubber coating on it. It's not on their web site or catalog so call them and they will know exactly what your talking about. BTW- they are cheap about 9 bucks. Any way measure up your deck height with sealant and then use the gasket instead if you need to. You'll have both on hand so you won't have to pull the motor apart twice. GOOD LUCK