I just rebuilt a 2002 Suzuki DF40 at work from the crank up..had a piston that had broken up from overheating (water passages were clogged with years of salt & crud). New internals, gaskets, etc, compression back to what it should be. When I tore her down, the timing marks on the intake cam were one link off...when I rebuilt the motor, I put the timing back to manual specs (marks on the colored links) and she runs absolutely flawless with one exception..if I come up on throttle easily fully trimmed down, it will build to 6k RPM. If I leave the motor trimmed about even and dog it, it will usually come up to full throttle easily. But trim all the way down and gag it from idle forward to full throttle, it will jump to 4500 rpm and the rev limiter will kick in and knock me down to 3k. Engage neutral and back to fwd gear it will allow me to build speed again. It's almost as if the engine were detecting there was too much load and just shuts down. Only thing I really changed was the timing on the one cam. With an EFI 40 is this enough to cause this problem, or is it now an issue with the ECU? I'm just trying to narrow down problems before I tear the power head back off to adjust the timing to a non-spec position. Thanks for any help or insight y'all might be able to provide.
