In the B&S forum, I got 56 views and not one comment. I hope for a better result here.
I have an old 3 hp toro 92908, self propelled, auto choke, fwd, b&s eng #1842-02. I have kept it running over the years with routine maintainance only, no major repairs. I keep the gas tank empty in the winter and fuel it in the spring. A year ago I replaced diaphragm with oe B&s, and it has run perfectly since. This spring, it started on the first pull after winter, but has a low, even idle speed at max throttle, just like at min throttle. The choke plate is closed, and snaps back properly when I open it by hand. Oddly, the idle becomes full speed when I manually open the plate to full vertical position while the engine is cold, not hot, on a fresh start. If I let it get hot with the choke plate held open, until hot, to get it to maintain full rpms, I am able to mow at full speed, and stop and start with no problem. I get no surges or roughness. There is no reason to think I have accidentally turned the idle speed or mixtures screws while in storage, and I find it hard to believe the NEW diaphragm has failed. Any suggestions to solve this problem appreciated.
I have an old 3 hp toro 92908, self propelled, auto choke, fwd, b&s eng #1842-02. I have kept it running over the years with routine maintainance only, no major repairs. I keep the gas tank empty in the winter and fuel it in the spring. A year ago I replaced diaphragm with oe B&s, and it has run perfectly since. This spring, it started on the first pull after winter, but has a low, even idle speed at max throttle, just like at min throttle. The choke plate is closed, and snaps back properly when I open it by hand. Oddly, the idle becomes full speed when I manually open the plate to full vertical position while the engine is cold, not hot, on a fresh start. If I let it get hot with the choke plate held open, until hot, to get it to maintain full rpms, I am able to mow at full speed, and stop and start with no problem. I get no surges or roughness. There is no reason to think I have accidentally turned the idle speed or mixtures screws while in storage, and I find it hard to believe the NEW diaphragm has failed. Any suggestions to solve this problem appreciated.