No Fire To Spark Plug 149 Cub Cadet

[J-Mech]

Originally Posted by twoton

Cause ultimately, what Bob is trying to do is get some extra amps into the system.

.......

Yes.

[twoton]

Originally Posted by J-Mech

Does any of that make sense or help?

Of course it does, and thanks for taking the time to put that up.

[sawdustdad]

While this is anecdotal, I have a K301 with inoperative ACR. It's in my 108 right now. It still starts, but when it hits TDC, the starter belt squeals for a second, then it rolls over. It usually catches the next time around or the sequence repeats. It rolls over, squeals, continues, fires.

I really need to fix that ACR (not sure of the cause, but will take the cam gear cover off to inspect when I get around to it. It has always started, so it's been down the list of priorities. It's either the spring off the cam gear or, worst case, the tab is missing. I bought this engine "rebuilt" from another collector, so I'm unsure of its origin/construction. It's been this way since I installed it.

Regardless of amps provided to the starter, the starter itself has limited torque and the belt/pulley arrangement has limited capacity to transmit that torque to the crankshaft. So getting more power to the starter may not help. Something else will give--usually belt slippage--or starter stalls out.

[Gompers]

Originally Posted by sawdustdad

While this is anecdotal, I have a K301 with inoperative ACR.

Hey, on the plus side, easy compression checks!

[J-Mech]

Originally Posted by sawdustdad

Regardless of amps provided to the starter, the starter itself has limited torque and the belt/pulley arrangement has limited capacity to transmit that torque to the crankshaft. So getting more power to the starter may not help. Something else will give--usually belt slippage--or starter stalls out.

Yes! That is correct. Just as a note here, the goal was simply to provide the ignition circuit with more voltage, not the starter. We already know with the ACR not functioning, that the starter is at it's max.



Back to the the water description:
In fluid power, we rate flow in gallons per minute. In electricity, it is measured in amps. In fluid power, pressure is rated in PSI (pounds per square inch). In electricity, it is measured in voltage. In fluid power restriction to flow is called resistance, and can be measured in PSI. In electricity, resistance to flow is measured in OHMs.

SO:
Pressure=Voltage
Flow=Amps
Flow resistance/friction=OHMs

If we took say 10 L/G batteries and hooked them in parallel (+:+)&(-:-) then we would still have a 12V system, but a much higher amp rating. If you then attached them to the starter it would have (basically) an unlimited amp source. The starter still has a maximum efficiency that it can go. Once that is reached, it doesn't matter how many amps are available, it can only do so much. Just like in fluid power the motor is subject to it's size, no matter how much fluid it has available. Now, if you increase pressure (voltage) you can "push" more power to that starter (or motor) but then the mechanical limit of the device (starter or motor) will be reached and it will eventually be overcome (fail). A starter will simply burn up, and a fluid motor will literally break.

[zippy1]

Originally Posted by J-Mech

Yes! That is correct. Just as a note here, the goal was simply to provide the ignition circuit with more voltage, not the starter. We already know with the ACR not functioning, that the starter is at it's max.



Back to the the water description:
In fluid power, we rate flow in gallons per minute. In electricity, it is measured in amps. In fluid power, pressure is rated in PSI (pounds per square inch). In electricity, it is measured in voltage. In fluid power restriction to flow is called resistance, and can be measured in PSI. In electricity, resistance to flow is measured in OHMs.

SO:
Pressure=Voltage
Flow=Amps
Flow resistance/friction=OHMs

If we took say 10 L/G batteries and hooked them in parallel (+:+)&(-:-) then we would still have a 12V system, but a much higher amp rating. If you then attached them to the starter it would have (basically) an unlimited amp source. The starter still has a maximum efficiency that it can go. Once that is reached, it doesn't matter how many amps are available, it can only do so much. Just like in fluid power the motor is subject to it's size, no matter how much fluid it has available. Now, if you increase pressure (voltage) you can "push" more power to that starter (or motor) but then the mechanical limit of the device (starter or motor) will be reached and it will eventually be overcome (fail). A starter will simply burn up, and a fluid motor will literally break.

Very good explanation "Professor" Jon.

[sawdustdad]

Jon, could have used you in engineering school, teaching basic electrical theory.

[J-Mech]

Originally Posted by sawdustdad

Jon, could have used you in engineering school, teaching basic electrical theory.

Lol, well, I'm not an engineer... but I did go to college. I had a couple really good instructors. We were told that you were either going to completely understand basic electrical theory, or you weren't. No in between. I just explained it like my instructor in college did, comparing it to fluid power. I understood it immediately. If ever I get stumped on an electrical issue, sometimes I have to go back to the fluid power angle of thinking. Once you understand it, it's really easy.

[twoton]

Good discussion and analogies.

Makes me think of my 1965 Essick vibratory roller. It had always been difficult to start. I does not get used much, stored in a remote location with no electricity, the battery box is small and can only accommodate a single battery and since the glow plugs in the 282 are rated at 11 volts, I cannot jump start it with my work truck.

So, I installed the largest CCA battery I could get, made up the largest and shortest battery cables I could and ran a ground directly to the starter mounting bolt. I also pulled the starter and had it rebuilt at my local starter/alternator shop. When I brought it in he confirmed that it was pulling far more amps than it should. All of this has made a big difference in getting that old beast roaring.

So Bob, again, if you choose not to fix the ACR, it may be helpful for you to make sure that all these other things are in the best condition they can be.

Good luck, and Happy New Year all.

[J-Mech]

Lots of glow plugs are 11v glow plugs. Still a 12V system. I don't know why you don't think you can jump it with your truck.... because you can.