Re: Modern setup vs. ancient factory propane specs on tractor
Posted: Tue Mar 05, 2019 11:28 pm
Thanks for the clarification, I had forgotten the way that the "idle circuit" works on the mixer - there is no idle circuit! Of course, since an idle jet would leak propane when stopped. All gas has to come through the gas valve, and the idle mixture screw just bypasses air to lean it out. So when the flow drops too low to open the valve, sudden stall. Makes sense.
I know not to lug too slow, I was just playing around after getting it tuned up. No load and kept a close eye on both oil pressure and throttle opening. I never would do anything under load at such low RPM, and the only reason I even would take it so low was because these old tractors were designed to work at fairly low RPM by our standards. The "turtle race" at vintage events is always fun to watch. I even saw a guy swinging an extra flywheel off the PTO shaft once to keep the motor turning over at around one stroke per second.
The real fear I had was the advance catching up to me. Those guys are usually running retarded. If I got really slow and lit the fire before the crank turned over at TDC... goodbye rods.
The tractor has been working great keeping the roads clear of snow. I may have to remove the PCV circuit as it cannot consume all the blowby gas that this old motor leaks under load. It ends up spewing oil from the breather that serves as the PCV intake, despite the mesh filter inside. Maybe I should add a catch can and route that breather to the air cleaner like you would see in a more modern PCV setup.
I know not to lug too slow, I was just playing around after getting it tuned up. No load and kept a close eye on both oil pressure and throttle opening. I never would do anything under load at such low RPM, and the only reason I even would take it so low was because these old tractors were designed to work at fairly low RPM by our standards. The "turtle race" at vintage events is always fun to watch. I even saw a guy swinging an extra flywheel off the PTO shaft once to keep the motor turning over at around one stroke per second.
The real fear I had was the advance catching up to me. Those guys are usually running retarded. If I got really slow and lit the fire before the crank turned over at TDC... goodbye rods.
The tractor has been working great keeping the roads clear of snow. I may have to remove the PCV circuit as it cannot consume all the blowby gas that this old motor leaks under load. It ends up spewing oil from the breather that serves as the PCV intake, despite the mesh filter inside. Maybe I should add a catch can and route that breather to the air cleaner like you would see in a more modern PCV setup.