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I have an older model 673 MTD Huskee 16.5 OHV 42" Cut RLM. In the past week it seemed to need a battery charge as it barely turned over but it did start. Last time I tried it had no juice at all so I charged the battery and still nothing so I hooked up some jumpers directly to the starter and it would turn over but there was no spark to start. Motor starts very easily so It has to be electrical???? I took the battery out and had it tested. It is good. Anyone have some thoughts. Thanks, Fuddyduddy.

check the valve lash.
Too much defeats the decompressor and the std starer is not powerful enough to overcome full compression while spinning the engine fast enough to generate a spark to start the engine.

Old starter checks out as well as the battery. When the starter was jumped, I used another 12Volt battery hooked directly to the starter. There is no juice to or from the magneto when the starter is jumped. I will check to see if the safety switches are all in place, tomorrow.

One minute you say it won't turn over the next you say it won't spark which one or both ?
Magnetos are self powering the wire is a ground wire.

How did you check the spark plug for fire ??

Take the plug out and then try to see if the engine turns over. If a bunch of gas or oil comes out then you were hydro locked.

You can check spark on the plug by holding it on a good ground while someone sits on the seat and turns the key... Carefully I might add...

If you do get a bunch of liquid out of the plug hole then you might have an issue somewhere else that needs attention..

Like Bert said the valve lash needs correcting more than likely. So when you take the plug out and it spins freely that is your problem. I set all mine at 4 and 4 Thousands that is.

I have never had one come back from setting at that setting in 3 years or so. Valves do get loose and needs adjustment every now and then ~!~!

Hope this helps ~!~!

bertsmobile1 said:

One minute you say it won't turn over the next you say it won't spark which one or both ?
Magnetos are self powering the wire is a ground wire.

Click to expand...

Sorry if that is not clear. The motor will not turn over with a good battery in it's normal place under the seat. It turns over fine with the jumper battery and my wife sitting in the seat and the clutch depressed. It has no spark and will not run. I know how to check that. It is like no one is sitting in the seat with the clutch depressed and the safety switches are retarding the normal operation.

Boudreaux In Eunice La. said:

How did you check the spark plug for fire ??

Take the plug out and then try to see if the engine turns over. If a bunch of gas or oil comes out then you were hydro locked.

You can check spark on the plug by holding it on a good ground while someone sits on the seat and turns the key... Carefully I might add...

If you do get a bunch of liquid out of the plug hole then you might have an issue somewhere else that needs attention..

Like Bert said the valve lash needs correcting more than likely. So when you take the plug out and it spins freely that is your problem. I set all mine at 4 and 4 Thousands that is.

I have never had one come back from setting at that setting in 3 years or so. Valves do get loose and needs adjustment every now and then ~!~!

Hope this helps ~!~!

Click to expand...

I had a friend ground the plug to the frame to check for spark while I jumped it. Plugs been out and we are past those issues. I was trying to keep it short and sweet because of the lack of big bucks you folks make putting up with a bunch of "fuddyduddys". Since there is no movement shown on the amp gauge and no clicking or any sounds when the key is turned. I have got to assume it is something electrical.

Check all safety switches, make sure none are going to ground.

Long is good.
Long and in time order is even better.
We have nothing to go on but what you tell us and past experience
So here is the long way to problem solve.
Not the only way, but my way.
Others will have different proceedures to get to the same place.
so here it is, bypass the bits you have already done

I like to start from the starter motor and go backwards .
Do the following 5 tests, regardless of the results from an or all of them as there can be more than one problem and you want to isolate where the problem lies.
Elimination of individual parts is important so you know by the end, the battery, solenoid & heavy power circuits are all in good order.

1) try to jump the starter motor directly from your car or truck.
Starter turns = starter good

2) do the same directly from the mowers battery
Starter turns = mower battery good
No turn = duff battery, recharge it & try again.

3) check for voltage ( + 12V ) at the solenoid trigger wire with the key in start position
3a) same with ground trigger wire ( 4 wire solenoid ) or body of solenoid ( 3 wire solenoid)
( I like to test V from the battery hot terminal to ground terminal rather than ohms as they give funny readings )

4) leave ground jumper in place ( from step 2 ) & try key start.
Starter turns = power connection good but ground connection suspect ( most common )
Confirm it by trying again, extra ground removed
I run a secondary ground from the grounding bolt to one of the starter mounting bolts & paint over both with liquid electrical tape.

5) Remove the trigger ( thin ) wire / wires from the solenoid.
Ground one & bridge from the hot terminal to the other.
Starter cranks = solenoid good.
Solenoid is not polarity sensitive, BUT THE WIRING IS so make sure you remove the thin control wires.
Note a thinner wire on the hot terminal is not a control wire. It is the main power feed to the mower.


From here on things become very mower dependant as starting circuits are getting changed all the time.
Basically the power goes in a loop from the hot side of the solenoid ( saves wire, no other reason ) through the fuse to the B terminal on the key switch then to the PTO switch then to the parking brake switch then to the solenoid trigger switch , easy peasy after you grow the 3rd arm. Use a test lamp and follow the power.
However a lot of mowers with a 4 pole solenoid, run a secondary ground control circuit to the ground solenoid wire through the lap bars.
Then to stop this interfearing with the normal safety function of the ground kill, it goes to a relay with the ground as the switched connection.
These are a PIA as the + control wire to the relay comes from the power loop above and the ground side of the control comes via the normal cut out functions of the lap bars.
Be very careful because if you have a system like this and accidentally send 12V down the ground loop you can fry the magnetos on some circuits.

Update. Stared at the mower this morning and checked to make sure the safety switches were all positioned well. Decided there were no fuses since the wiring diagrams didn't list them and then commenced to wiggle wires and check for loose connectors. That all "seemed" good. I then located the wiring for the solenoid and did my best to check it out. Cleared out a little debris and lo and behold, there is a small single spade fuse box and a 20 amp fuse fastened right next to the solenoid. Removed the fuse and discovered it was shot, so I took a trip over to Auto Zone for a few fuses. That did the trick(for now?).After giving it a good test....mowed my lawn.... I decided to look at my wiring schematic again. There was a drawing of it and the fuse harness but no mention of a fuse on the numerical list of any of the schematics I had access to. They say that "it is often better to be lucky than good" This time I was very lucky". Thanks all for the effort and time...........Fuddyduddy

Thanks for letting us know, good luck.