Yanmar powershift

[Gary Fowler]

I recently purchased a Yanmar 4220 D with FEL. When I first started using it to bushhog, it ran fine for a few hours then it stalled out. The first time it stalled down the engine, I thought I had ran into some really tough grass and overloaded it. I disengaged the PTO and restarted the tractor then engaged the PTO and it worked fine. A few minutes later it stalled the engine again, but this time I noticed that the bushhog was still freewheeling. It did this about 4 more times, then I noticed that the 4 WD lever was about half way between engaged and disengaged. I moved it all the way to 4WD and continued to work and it has not happened again.
When the engine stalled it was running at full throttle and it was like the clutch was released with the wheels locked and it just squelched the motor to a stop. It restarted easily and ran perfectly. THe last time, it stalled I decided I would go to the house and call the dealer and it stalled 4 times in about 300 yards, but each time it started right back up. I could not reach the dealer and after looking over the tractor, I found the lever and moved it. So far it has not happened again in about 20 hours of running.

Has anyone else ever experienced anything like that. I still dont know if the 2/4WD lever had anything to do with it.

[PaulChristenson]

You'd probably get better answers in the Yanmar forum...

How many PTO HP is this tractor?
How big is the bush hog you are running?

[Gary Fowler]

The tractor is about 50 PTO HP and the bushhog is 6 foot. Like I said It stalled just running down the road in 3rd high range with nothing turning but the wheels. This happened 3 times while trying to get it from the pasture to the house. The tractor made a squealing internal noise like a big brake had been applied around the drive and it just stalled down the engine. It did it once even with the tractor in neutral and setting still.