SA 424 Pto issue - Motor dies when engaged

   / SA 424 Pto issue - Motor dies when engaged #1  

BMan Idaho

New member
Joined
Jun 8, 2024
Messages
5
Tractor
Yanmar SA424
Hi All - Searched the forum but didnt find any info that helped my situation.

I recently bought a used SA 424 - it was part of the home depot rental fleet liquidated through richie brother

It came with loader and backhoe - Everything worked great except the pto switch had been broken off -
I purchased a new switch - removed the backhoe and mounting bracket -
When I pull the switch the pto spins for about a second then the engine shuts off?

Is there something I am missing - is there a certain sequence for engaging - I did rev engine u to 3500 (if that matters it looks like thats what the speedometer says you need)
NONE of the labels are left showing what each lever switch is - I have looked through the manual but havent had any luck - am I missing something simple?

Thanks in advance
Brian
 
   / SA 424 Pto issue - Motor dies when engaged #2  
Are you on the seat when it dies?
 
   / SA 424 Pto issue - Motor dies when engaged
  • Thread Starter
#3  
sitting on seat when I engage and it dies - lower rpm I had someone else watching for me

went back out and made sure to sit on seat and get RPMs up and it worked - Much thanks I tried multiple times and must not have had the rpms up high enough when I tested with a friend watching-
 
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   / SA 424 Pto issue - Motor dies when engaged #4  
Make sure to engage the PTO with the engine near idle and then slowly raise the engine speed to the rated speed (540 PTO rpm = 3120 engine rpm). Engaging at full speed will break sheer bolts.
 
   / SA 424 Pto issue - Motor dies when engaged #5  
Make sure the seat is down as far as it can go.
Try to reset the seat, pop it up and flip it up and then wiggle the seat and push down.
I know if my seat is not in the right spot it will do the same thing.
 
   / SA 424 Pto issue - Motor dies when engaged
  • Thread Starter
#6  
Thanks for the additional replies - I have been putting the tractor to use
I have just finshed about 50 holes and no issue -

But while using the pto for the auger I realized the ONLY way the PTO will work (and not kill the engine) is if the brake is engaged.
For an auger this isnt a problem but what if I get a brush hog or a snow plow?

I am thinking a safety feature

I have been reading the internet and not found much - any ideas?


Thanks again
 
   / SA 424 Pto issue - Motor dies when engaged #7  
Sounds like something in the seat safety switch is killing it. Maybe not fully making contact.
I had a similar John Deere Yanmar, and you could run the pto if the brake was set and tractor out of gear, even while off the seat.
 
   / SA 424 Pto issue - Motor dies when engaged
  • Thread Starter
#8  
Ordered and installed a new seat switch and the pto now works with no brake - thanks for the help
 
 
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