Q. Ok, we tried the new 00-5 cam and our motor builder told us not to turn our motor past 6400 RPMs, he also told us he always runs 33 degrees timing, could this be the reason why our 00-5 cam will not turn up more than 6600 RPMs? We even tried changing the gears to get the motor to turn more RPM, and we were not able to. Tell us what you think.

A. Timing is probably the key factor in the above scenario. You should know that the lower the timing, the higher your motor will rev. Realize though, that lowering your timing adversely effects bottom end performance. Lower your timing too far and everything suffers. If your engine builder told you not to turn the engine over 6400, then he probably built it to run 6400 or less. If you want to turn the engine 6600 to 6800, I would back your ignition timing down to 29 to 30 degrees.* Then make sure your valve lash is approx. .003 to .004 Finally and most importantly, would be your valve spring selection. You will need at least 18 to 18.5 lbs on the intake and exhaust. I would also recommend a high-performance pipe like the RLV-5734 or SOX Loop Pipe.

*All measurements based on stationary timing. Operational timing differs by as much as 5 degrees from static or stationary timing. The Briggs timing mechanism gradually retards up to as much as 5 degrees as the motor turns up to it's operating speed.

Well, that's that.  We hope you've enjoyed this installment of "The DynoCams Tech Section".  Join us next month as we delve into other mysteries of Karting issues.