OutdoorKing Repair Forum Forums Repairs and Maintenance Questions On Ride On Mowers Questions On Ride On Mowers Frames Viking MT433H - start issues

Hi there,
my parents have a viking rideon lawn mower - model no. 40567X53B and we're having major issues getting it to start. Some days it starts no hassles, and then others, like today, it makes no attempt to start. I thought maybe it could have something to do with the switch under the seat, however, I'm not so sure.
Does anyone know of some simple solutions that I may be missing? I'd really appreciate your thoughts

Hi Vanessa, the first question is, what happens when it fails to start? Does the starter motor crank the engine, but the engine does not fire up? If so, by my reading of the wiring diagram, the seat switch is a possible culprit. The other safety switches (PTO and clutch brake pedal switches) seem to disable the starter solenoid as well as the ignition, but the seat switch only disables the ignition. However there are other things that can disable the ignition - such as a defective ignition module, a faulty ignition kill wire that is being intermittently grounded, a faulty PTO switch NC contact, or a faulty start switch.

If someone involved in this has experience working on fixing faults in potentially dangerous machinery, you can use a process of elimination. However this requires that some basic safety rules be followed explicitly. The first one is, only one person works on the machine and all others stand well back. The repairer temporarily disconnects the ignition kill wire (the yellow wire going to the start switch terminal no. 4). If the engine starts and runs properly with the kill wire disconnected in this way, but does not do so with it connected, the fault is in the kill switch circuit downstream of the start switch. Reconnect the kill wire as soon as you establish this - the machine is unsafe to operate without it, and you can't stop the engine except by grounding that lead anyway. If it isn't the kill switch circuit, tell us that, and tell us more about the symptoms, and we'll talk about other possibilities. If it is the kill switch circuit, we'll talk about how to check the various parts of that circuit.

Remember, that lawn tractor is a dangerous machine. One test at a time, only one person working on the tractor, that person fully in control of the operation and well-briefed, and think first before making a test. I've had to sit through briefings on how skilled tradesmen in a very safety-conscious company managed to kill each other when two of them worked on a job successively, and something went wrong with the hand-over procedure. Do not let this happen to you.

wow! Thankyou so much for such a detailed reply. I will answer your question first just in case it helps at all. The starter motor doens't crank the engine. No effort is made at all. It's completely dead.

zz

You can download the technical manual for the machine from here:

http://www.outdoordistributors.com/pdf/Murray/MURRAY-MODEL-40567X53B-LAWN-TRACTOR-%282001%29-PARTS-LIST.pdf

The wiring diagram is on Page 6. Joe, as I read it the seat switch only grounds the kill wire if there is noone on the seat, it doesn't seem to affect the starter solenoid. The only other safety switches I've found are on the Power Take-Off and the clutch-brake pedal, and both of those two kill the starter solenoid as well as the ignition.

Vanessa, if the engine sometimes does not crank, you may have a flat battery or a loose battery terminal clamp. These are more common faults than something wrong with the safety circuit. You can check whether this is the problem with a voltmeter attached to the terminal clamps (not the battery posts themselves). If the voltage drops way down - say 5 volts - when you hit the starter, that will be your problem.

If you want to test the seat switch, just disconnect either of the two yellow wires attached to it and see if the problem goes away, but at present I do not see how that could help since it does not seem to affect the starter solenoid.

If there is sufficient voltage across the battery terminal clamps when you hit the starter switch, but the engine does not crank, the next thing to check is the other two safety switches (PTO and clutch/brake pedal). I'm guessing you know that you have to disengage the PTO and push the pedal when you crank the engine, or nothing will happen. This is a safety feature that is also used on American cars with manual transmissions built in the last 40 years - it keeps people from starting the engine when the car is in gear (or the PTO is engaged, which could cause an attached piece of machinery to rotate and hurt someone). Those two safety switches are connected to the starter solenoid by orange wires, and probably the easiest way to test them is to check whether 12 volts suddenly appears at the starter solenoid's activation terminal when you try to start the tractor. If you have the PTO disengaged, sit on the seat, push the clutch fully down, when you hit the starter, you should see battery voltage on the terminal where the orange wire connects. If you don't, the fault is in the safety wiring, and will probably be a defect in either the PTO or clutch switch.

Please bring us up to date after checking these things. AND BE CAREFUL - THAT IS NOT A CAR, IT'S A FARM MACHINE. PEOPLE OFTEN GET HURT OR KILLED BY FARM MACHINES.

Very good reply guys,on my mtd i had the same problem so i sprayed wd-40 into the switches and cleaned all terminals of rust/dirt/corrosion also if mine is in reverse with the p.t.o(blades)on-if running the engine will stop,must be in neautral to start .mine also has a inline blade fuse...ken

Hi again!

Our Viking MT433H has just had a bit of a blowout. With thanks to your technical specs pdf from this 2010 correspondence we were able to identify our shattered part on page 10 as item number 34.
http://www.outdoordistributors.com/pdf/Murray/MURRAY-MODEL-40567X53B-LAWN-TRACTOR-%282001%29-PARTS-LIST.pdf
Thus on page 11 item 34 is called part number 1001046 and it�s name is Mandrel.
Is there any chance you or anyone else could advise us on where if at all possible we might find a replacement for this part? Either Melbourne or Tasmania would be fine

Cheers!

This is the part I get using the part number you have supplied on the Online store

The bits that make up that assembly are available individually, Joe. I suggest Vanessa needs to check carefully what is damaged. Very likely a complete spindle assembly will be the best solution - I can't tell without seeing the parts or knowing what happened to cause it to break. The housing alone is over $50.

On the onlines store entering the part number brings up the whole assembly, for the sake of $86 its cheap insurance as the whole assembly has new bearings, shaft, etc.

Unless Vanessa has a good set of tools including a hydraulic press, and a fair amount of skill, if the housing is broken, buying a complete assembly is a good way to go in my opinion. Even if the shaft, bearings and oil seals are in really good condition, the assembly job is much more likely to be faultless in a factory-build assembled part.