I had reservations about doing this on a new snowblower, but I have to tell you, this engine runs even smoother than it did before. After the new carb was installed, I figured it didn't need to be started using full throttle as you normally would have to do. After two hits of the primer, I raised the throttle to just over the idle position, and it started on the first pull. In fact, it was much easier to warm up with the modified carb than it was with the original one. I found I didn't have to manipulate the choke settings to keep it running as I did before.
After a good warm-up, I raised the throttle to maximum and adjusted the high-speed main fuel mixture. When the engine smoothed out, I lowered the engine speed to the idle position, only to find it was idling at 1,550 RPM's. Amazing, because the EPA carburetor had to idle at 2,300 RPM's. I did a fine adjustment to the low-speed mixture until it was at its smoothest. What was most obvious to me was just how smooth it ran at any speed. Normally there was just enough vibration that it would translate to the very long chute on this snowblower, but not anymore. Aside from the noise these snowblowers make when running, if you grabbed the handle bars, you were only able to detect the slightest amount of vibration.
The only surprise I did notice was that after the carburetor was fully set, the maximum engine speed had increased to 3,500 RPM's. I did make a minor adjustment to the governor to bring the speed back down to 3,400 RPMs, what it was set at prior to all of this. Having to lower the governor setting, made it apparent to me just how much power gets robbed from the EPA carbs. I suppose I have to look at it as the engine having that much more power available when the automatic governor kicks in when under a heavy load. I'll put this machine up against a 10 hp snowblower any day of the week.
