Murray/ Noma lags or fails to turn over when key turned.

[mstar]

Hello this is pretaining to a 12 HP Briggs and Stratton engine in a Noma/Murray riding mower with 4 wheel steering from 1989 sold under the AMF/ Agway brand.

Engine 281707 type : 0425-01 Code 89103031 Cast iron bore.


The problem is when I turn the key the solenoid clicks but there is sometimes no activity or a little fraction of the turn of the fly wheel. Then if I turn the key off and on it usually will turn but a little weak. In the summer it is enough to start it. This can happen even if it has been warmed up and running.

First I cleaned all the electrial connections from the starter back to the solenoid, Solonoide was removed and ground point cleaned shiny on the frame and the connection points. Main wire to the starter was replaced a couple years ago and the one end I changed to copper yesterday since itw as the wire was a little corroded. I had the extra end from the package so replaced an end on the battery cable since the steel ends will rust over time. I made sure all terminals were clean and the ground was touching shiny metal.

I had replaced the solenoid a about 5 years ago so it is not original. I had to replace the key switch last year due to a broken key. I had to change the ignition coil two years ago due to mice making a nest around there that caught fire and melted the spark wire. I used the shim to set the coil.

Fly wheel is a bit rusty.

The battery was replaced in 2010 with an interstate brand battery. I noticed the positive terminal looked wet after charging in the basement this winter. I am not sure if that was condensation from the damp basement or a leak but the volt meter says it is holding the charge. The alternator is putting out a charge back to teh battery.

I am not sure about the amps in the battery to know if I still ahve my cranking amps. can you have 12.5 volts but still not have the cranking amps it needs?

Otherwise I do not knwo what else would cause the lagging start when you turn over the key. You hear the click at the back and but it is like a delay if it is going to turn over at all.

it will spin right up without the spark plug in place if I recall.

If it turn the key off and try again the engine will usually rotate, The more you do it in a row the faster it seems to turn. It can start but as I said, it lagges to want to turn even if you have had it warmed up.

Currently since I was playing with it , I wound it down to 12.2 v . I am charing it now to see if 12.5/6 changes anything. Then I will assume it was the battery
But since I do not really know how to check out the engine or the magnets and what might help make it turn easier, ect I am at a loss what to check.

Thanks
Mark

 

[EngineMan]

I would now work on the starter motor, but are you up to it...? if not take it to someone who can do it for you, it may just need a set of brushes but when you have it apart give it a good clean and then test the armature and field coil to see if any are defective. also weak brush springs, look for dirt and oil. if you do undertake the job make sure when you put it to lightly lubricate the end cap bearings.
starter motors are not that difficult to do, I've done 100's of them but can be a little off putting if you have never one before.
You can always take it repair shop if you feel not up to it....:smile:

 

[SeniorCitizen]

Hello this is pretaining to a 12 HP Briggs and Stratton engine in a Noma/Murray riding mower with 4 wheel steering from 1989 sold under the AMF/ Agway brand.

Engine 281707 type : 0425-01 Code 89103031 Cast iron bore.


The problem is when I turn the key the solenoid clicks but there is sometimes no activity or a little fraction of the turn of the fly wheel. Then if I turn the key off and on it usually will turn but a little weak. In the summer it is enough to start it. This can happen even if it has been warmed up and running.

First I cleaned all the electrial connections from the starter back to the solenoid, Solonoide was removed and ground point cleaned shiny on the frame and the connection points. Main wire to the starter was replaced a couple years ago and the one end I changed to copper yesterday since itw as the wire was a little corroded. I had the extra end from the package so replaced an end on the battery cable since the steel ends will rust over time. I made sure all terminals were clean and the ground was touching shiny metal.

I had replaced the solenoid a about 5 years ago so it is not original. I had to replace the key switch last year due to a broken key. I had to change the ignition coil two years ago due to mice making a nest around there that caught fire and melted the spark wire. I used the shim to set the coil.

Fly wheel is a bit rusty.

The battery was replaced in 2010 with an interstate brand battery. I noticed the positive terminal looked wet after charging in the basement this winter. I am not sure if that was condensation from the damp basement or a leak but the volt meter says it is holding the charge. The alternator is putting out a charge back to teh battery.

I am not sure about the amps in the battery to know if I still ahve my cranking amps. can you have 12.5 volts but still not have the cranking amps it needs?

Otherwise I do not knwo what else would cause the lagging start when you turn over the key. You hear the click at the back and but it is like a delay if it is going to turn over at all.

it will spin right up without the spark plug in place if I recall.

If it turn the key off and try again the engine will usually rotate, The more you do it in a row the faster it seems to turn. It can start but as I said, it lagges to want to turn even if you have had it warmed up.

Currently since I was playing with it , I wound it down to 12.2 v . I am charing it now to see if 12.5/6 changes anything. Then I will assume it was the battery
But since I do not really know how to check out the engine or the magnets and what might help make it turn easier, ect I am at a loss what to check.

Thanks
Mark

QUOTE: I am not sure about the amps in the battery to know if I still ahve my cranking amps. can you have 12.5 volts but still not have the cranking amps it needs?
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Yes you can. That's very common to have volts but not amps.

Before investing in parts that aren't needed, try jumping directly to the starter from a battery of known good condition like a automotive battery that cranks your car.

If the engine is an overhead valve engine , valve adjustment has solved similar problems but sadly to say after way too many dollars have been spent on UN-necessairly on parts.

If it acts similar jump starting with a known good battery, the valves ( if OHV ) are a likely suspect. The starter was only built for X number of amp draw and no compression relief can easily peg that little starter out at around 300 amps. Normal cranking amps will be closer to 100 amps.