Yardman model 604 dies when I press pedal to move (after new drive belts)

[Bentoolong]

Thanks for allowing me to join.

I have an early 2000' Yardman 604. I just got this to work on a month ago. The drive belts were not long for the world but they did work.

I just purchased and install MTD branded 754-0467 and 8 from Rotary.
Put them on this morning.
I have gone over the routing. All belts seem that they are routed correctly all pulleys are free as well as the vari-drive. The center of the varidrive is free to move.

I do not have the deck on so I need to play with the deck engagement lever a little to get the machine started. Once I get it running I can leave the lever alone. I can't imagine that I. need to have the deck on to get the mower to move. I recall driving it without the deck before the new belts.

If I put it in forward and push the pedal it starts to move and then the engine quits. In reverse It almost quits as soon as I put it in R.

I haven't done any other adjustments other than tighten the brake adjustment a little. That seems to work better.
No rolls in the belts. There is a little slack in the belt when the pedal is depressed. Press the pedal and the drive belt tightens nicely. The adjustment on the little bracket seems to be good. 1 3/8" of movement before some engagement.

What am I missing?
Mark

 

[ILENGINE]

I suspect there is something going on with a safety switch. Either a seat switch issue or a pto switch in combination with the reverse safety switch. Mower is thinking that you are not on the seat or you have the deck engaged while trying to back up.

 

[Bentoolong]

That makes sense. It doesn't seem related to the belts since it happens suddenly. As I stated, I don't have the deck on and I need to fidget with the PTO lever to get it to run.


How does the deck interlock actually work since the deck runs if you are moving or not. If it works in tandem with the seat switch that's another matter. I can start it so something on the seat switch is working.
Time to look at my schematics.

 

[bertsmobile1]

Seat switch + PTO switch on one circuit
Seat switch + parking brake on another circuit
Reverse switch + PTO switch on a third

These are all switches which ground out the magneto if
1) blades are engaged without operator in the seat
2) operator leaves the seat without the parking brake turned on
2) attempt to mow in reverse

Most are either Ground or open circuit unless relays are used when they can be either a ground or a power switch as a relay can be triggered from either the power or ground side.


While all mowers are essentially wired the same, we need the MTD model number ( one that starts with 13 or 14 ) to track down the actual wiring diagram for your mower.
They are the same but can be done differently using relays or switches in tandem so I could not give you any more help without becoming confusing.

Read your owners manual.
Some will have a wiring schematic in the back but most MTD products have a wiring diagram in the back of the parts books.
Your parts book is a free download from MTD but you will need both the model & serial numbers from the tag under the seat.

 

[Bentoolong]

The model is 13AK604G401.

I have the original owners manual. I even have a VCR of how to install/remove the deck.

I also found what I think is a schematic of this model.

I want to think that it has something to do with the PTO interlock. I plan to look into this more soon.

Should I have the deck on to test this out or can I run (move) the tractor without the deck installed.

Thanks again for your help.
Mark

 

[bertsmobile1]

This model comes with 3 different decks
one has electric clutch & the other 2 have manual PTO engagements
If yours is the later make sure the PTO lever is fully in the OFF position.
On a lot of mowers without the deck in place there is nothing to hold the lever in the off position so it can look like it is off but not be far enough back to depress the PTO interlock switch plunger in far enough.

 

[Bentoolong]

Simple thing. I bungee corded the PTO pulleys to the back of the tractor and things are good.
Still doing some engine work but plan to have that done soon.

I see the method to adjust the belts is to have the idler pulley mechanism have around 1 3/8" movement with around 10LBs of pressure on the pedal
I'm interested in getting the belts adjusted so that I am running at optimal speeds.
Is there a better way to set this? It seems I have more. than enough slack in the belt at this point and I do have around 1 3/8" movement in the idler frame.
Just curious if anyone has a method of adjusting.

 

[StarTech]

Well take is the MTD's way of setting the adjustment per thier 600 series auto-drive service manual.

 

[Bentoolong]

Well take is the MTD's way of setting the adjustment per thier 600 series auto-drive service manual.

I'm not sure what this means exactly.

 

[StarTech]

I'm not sure what this means exactly.

Bad post that I actually didn't post myself. One of my critters did it. We had a go around which got them thrown out in the snow @ 20F. Boy was they happy to get back in 10 minutes later. Please accept my apology for not catching that one of them hit the post key.

But the proceedure you described in post #7 is the one in the MTD 600 series auto-drive service manual.