engaging pto makes my 312-8 engine die

[JCD 78]

I've run into a strange problem, started up the 312-8 and went to mow but as I engaged the pto it started bogging down and would die if I kept pushing the pto lever forward.

 

It doesn't die when the pto first engages, the belt turns and so do the blades but if I push it forward more than a couple of inches it kills the motor.

 

No smell from the belt or any burned areas that I can see.

 

I decided to try and drop the deck, haven't done it before, dropped the bar from the attach o matic but then it started to rain so I struggled to get the bar reattached, had to use 2 jacks to hold it in place while I locked it in.

 

When I did that I noticed the belt seemed very loose so I tightened it up but the deck looked funny, the front was higher than the back, when I went to lift the deck it was apparent that something had become detached or broke because my lift arm is loose.  

 

I can see a chain moving up and down but it's not connected to anything anymore.

 

Anyone know what has happened and how to fix what I messed up?

 

Thanks, Jim

[wallfish 18,071]

The safety switches are shutting down the ignition. The PTO switch is connected to the seat switch so the PTO can not be operated without someone sitting in the seat.

You will need to diagnose where the problem is in the wiring or a switch. Search the files and download the manual for your tractor and it will have the wiring diagram in it. 

[davem1111 2,156]

Assuming you were in the seat and the seat switch was engaged, as Wallfish stated might be the problem, it sounds to me like your lift arm became detached from the chain that goes up to the rocker arm, and possibly dropped down to interfere with the turning of the center pulley.  I guess if your PTO clutch is good and your belt isn't slipping, that could be enough drag to bog down the engine.  

 

Let's see what the experts here say - I'm not one of them 

 

[gwest_ca-(File Mod) 11,450]

Make sure you get the correct wiring diagram. Let us know if you need help.

The ignition systems used on the 312-8 changed and improper testing can release the magic smoke in the wiring.

 

When attaching a mower to the tractor there is a forked tab that must be installed correctly at the mid-hitch for everything else to fit. The mower deck operator manual will have this illustrated.

[JCD 78]

As far as I can tell all the safety switches have been removed.  

 

Is there anything else that could cause the pto engagement to kill the engine?

 

It literally sounds like it is bogging down and cutting out, once it starts to bog I can pull the lever back and the engine will roar back to life.

 

Seems that a safety switch would just stop the engine not allow it to keep running by pulling the pto lever back and I can do this repeatedly, ease it forward, start to bog, pull it back and running 

 

I plan to drop the deck when I get back up to the tractor and see if the blades are hitting anything but I know they are moving when I first engage the pto as I can hear it and see air and some grass blowing out from the edge of the deck.

[wallfish 18,071]

Maybe a blown bearing in the bell in the housing???

The easiest fastest way to determine if the issue is at the deck or not is to take the belt off the PTO and engage it.

[JCD 78]

Thank you Wallfish, I didn't think of that.

 

I'll do that first thing when I head up Tue.

 

Jim

[ohiofarmer 3,372]

Look down under the engagement lever for the fuse block. ( If there is one) I jF that problem before and blew grass clippings and dust out of the fuse block and sprayed a bit of penetrating oil in the fuse block and it worked again

.

    Love my 314 but not a fan of the Christmas tree lights and excessive safety switches 

 

[953 nut 59,785]

First you need to get your mower deck attached properly so you can check out the belt movement by hand with the engine turned off. This manual will guide you through the proper alignment for mounting. There could be a bad bearing in PTO bell, the mule drive, or on the deck.

 

[Brockport Bill 1,932]

Disconnect the mule belt to pto then engage pto would be good starting point for diagnosis to determine cause and effect?...,

Also try other suggestions mentioned by others..also could be frozen mule pulleys causing stress resistance beyond what engine can power when you engage pto lever