Hi,

Here's a good one for you guys...

My Kioritz on my custom Phoenix seemed to be a little down on power from what it had. Then I noticed when checking with the tach at full throttle on the ground that it was going "flat" at full throttle. It sounded and acted like it was lean and sagging. Further checking however showed that what was happening was that the throttle was going past full, and starting to close off the butterfly a bit at full throttle. I had mentioned this here before as a heads up for everyone. I always cut the throttle stops off and just set the throw with my computer radio so that there is no chance that the throttle will go to the stop and bind the linkage and cause a big battery draw.

However, I had carefully adjusted the throttle linkage and radio so that I had precisely full throttle as it should be. Long story short, what I discovered was that my linkage had just enough slop in it that when the engine was running, the engine vacuum would suck the butterfly past full throttle to about 7/8 open. It would lose about 400 rpms. I had to readjust my linkage so that when running it actually got full throttle! This could be something easy to miss, and it definitely cost some power. Try to keep your linkages as slop free as possible, and check for full throttle while running. (Be very careful doing this!)

Hope this helps someone,
AV8TOR