Murray stalls when blades engage

[ben.cellamare]

Just finally got my older Murray back to working order, but when I engage the blades the engine stalls. Any ideas why? I originally bypassed the seat switch so that is not even an issue at this point. Any direction would be helpful. Thanks

 

[bertsmobile1]

The safety circuits are all ground circuits so if you have a short anywhere it will not make any difference weather you bypassed a switch or not .
When you turn the blades on you do several things
1) Activate a safety circuit PTO + Seat Switch
2) Start spinning the blades
3) Open the throttle further .

So while you have the belt off turn the blades on
If the mower dies you have an electrical problem
If not it is mechanical or fuel related

NExt test is to set the parking brake and manually open the throttle by pushing the governor arm
If the engine faulters then you have a fuel problem

If both of those are negative then the problem is with the clutch itself

 

[ben.cellamare]

The safety circuits are all ground circuits so if you have a short anywhere it will not make any difference weather you bypassed a switch or not .
When you turn the blades on you do several things
1) Activate a safety circuit PTO + Seat Switch
2) Start spinning the blades
3) Open the throttle further .

So while you have the belt off turn the blades on
If the mower dies you have an electrical problem
If not it is mechanical or fuel related

NExt test is to set the parking brake and manually open the throttle by pushing the governor arm
If the engine faulters then you have a fuel problem

If both of those are negative then the problem is with the clutch itself

I will try and keep you posted. Thank you

 

[ben.cellamare]

The safety circuits are all ground circuits so if you have a short anywhere it will not make any difference weather you bypassed a switch or not .
When you turn the blades on you do several things
1) Activate a safety circuit PTO + Seat Switch
2) Start spinning the blades
3) Open the throttle further .

So while you have the belt off turn the blades on
If the mower dies you have an electrical problem
If not it is mechanical or fuel related

NExt test is to set the parking brake and manually open the throttle by pushing the governor arm
If the engine faulters then you have a fuel problem

If both of those are negative then the problem is with the clutch itself

So I took the belt off and engine still turned off. I tested the clutch sensor and the blade sensor, both of them work (have continuity). And the seat safety switch I bypassed.

I will try the governor arm next.

 

[bertsmobile1]

It is electrical
Engaging the blades without the belt will not put enough load on the engine unless the battery is dead flat .
So either there is a dead short in the PTO circuit or a ground short in the blade safety circuit .

 

[ben.cellamare]

It is electrical
Engaging the blades without the belt will not put enough load on the engine unless the battery is dead flat .
So either there is a dead short in the PTO circuit or a ground short in the blade safety circuit .

what is the best or easier way to find the short?

 

[bertsmobile1]

No easy way to do it .
You have to unplug everything then plug them back in one at a time till you find the culprit
You really need a wiring diagram to make sure you do not cross a power circuit with a ground circuit .
I use short jumpers to make connections on the power side then one at a time connect the ground till the engine stops or I get a ground on the kill circuit depending if I have the kill wire test lamp with me .

We have now got to the point where you need to tell us a lot more about your mower.
Starting with the model number
Electric or manual PTO etc .

 

[ben.cellamare]

This is the wiring diagram. I have a Murray 38608x92c with a manual PTO

 

[ben.cellamare]

Here it is

 

[ben.cellamare]

I have a new ignition switch. 15 and 16 is the blade engage switch I have pulled it and tested it and it works so there must be something electrical as you stated.