Richmond, VA, USA
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The engine iteslf is fine, but the pump and carb can be VERY, VERY challenging to tune. The set up will typically try to run lean in the midrange when the high speed needle is correctly set. You can improve matters by replacing the carb's metering slot ("cat's eye") with the one from the 60K carb, but that's a band aid at best. Guys have typically only achieved statifatory results from this engine longterm by replacing the carb with at the very least one from the non PS C-Spec or, much batter, the Cline/OMI carb set up. They can be had for good prices second hand here on RR if you watch closely. Also note that this engine is UTTERLY INTOLERANT of ANY lean runs, not a good feature when the stock PS carb is notorious for letting the engine go lean.
The peak power band rpm of the engine is less than that of the SZ because of the engine's timing. The engine is overall less powerful than an SZ as you might expect from a motor of earlier design.
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