Sthm PTO Issue?

[Morson82]

Hi all, just want to say I love these forum sites, lots of good people pot there with lots of knowledge..
Well, I have a sthm with around 1000 hours on it. It has a cvs23 Kolher engine.. The mice got to the spark plug wires earlier this summer and I spliced the wires, not wanting to replace the entire magnetos AGAIN. Anyway, I put a new battery in it at the beginning of summer and a couple weeks later it was dead. I jumped it but the battery never really held a full charge after that. I jump it ever time now.
Today I went to cut the lawn and had a hard time starting the mower. After getting it going I got out to the front lawn and when I went to power up, the engine was misfiring. It appeared that the temp fix of the damaged plug wire had come undone. So I took the top engine cover off and did a better temp fix of the wire and she started right up and sounded great. So I put it all back together and drove out onto the lawn again and when I hit the PTO
switch the engine began stuttering and back firing, like the load was too much. The sound of the engine changed and there was a lot of smoke coming out of the oil breather. I tried this several times at different speeds and I could not get the blades to spin properly or the engine to run smoothly. Then I turned on the PTO and the engine started to die but the pto did not come on. When i turned the switch off the engine back fired and then resumed a normal idle. I did this multiple times and the PTO would not activate and the engine would sound overloaded. I turned the engine off and then started it and tried the PTO again. the PTO would engage but would not let the engine and blades get to proper rpms.

After messing with it a little more I was able to get the blades and engine running at what seemed normal and was able to make several cuts and hen the PTO cut out and he engine died. I restarted the engine and tried the PTO but it would not engage and the engine began stuttering and sounded over loaded.

A month or so ago, my PTO started cutting out while I was mowing and when I checked the wires behind the switch it was so hot that it actually burnt my finger, blister and all. The clip part of he harness that goes to the back of the switch was burnt and slightly melted. I was able to rig it to work and it has done so up until now.

Not sure what's going on, could the dead battery be causing this. I have to jump it ever time now.

 

[Mad Mackie]

Hi Morson82,
Judging from your comments, here are my thoughts;
When mice get into a machine and do damage to the electrical system, they can cause a multitude of problems.
Initially, I think that the charging system is not working. The charging system needs to work correctly in order to supply enough power to all the systems on the machine, the biggest amperage draw of all in the system being the electric clutch, which can draw up to 7 amps. The next item is the fuel shutoff solenoid on the carburetor, which draws about 1 amp, and the electronic safety module that monitors all safety circuits and either allows the machine to continue to operate or shut it down if any safety circuit is compromised.
I recommend that you disconnect the battery and charge it. A 10 amp charger may need to be left on the battery overnight to get a full charge into the battery. A 2 amp charger may do the job but will need to be left on the battery for a long period of time. Check both fuses, one is in the battery positive to the electrical system, the second is in the charging system output to the key switch.
Reconnect the battery and run the engine. Bring the engine to full RPM and let the charging system stabilize and check the voltage across the battery terminals. It should be 14.1-14.4 VDC.
If all checks out OK to this point, then the PTO/electric clutch can be checked out.
Let us know how you fair with troubleshooting and if you are capable of performing these checks.
Mad Mackie in CT

 

[Morson82]

Well, after sleeping on it, I decided to replace the coil that I made the splice on. The wires in those are not solid core or multi strand solid copper wire. They are very thin, almost fiber like. I also replaced the pto switch and the fuel pump. Neither the switch nor the pump were a cause of the issue, but both were original to the machine and I felt it was time to change them out. After putting it all back together she fired right up. I let her run for a few minutes and then activated to pto switch and........she purred like a kitten. I think the resistance of the splice in the coil wire was too much and was causing the engine to misfire. I even went so far as to wrap the coil wires with stainless wire to keep those dam mice from eating them. Thanks to Mad Mackie for the response. I live in Colchester.

 

[Mad Mackie]

Hi Morson82,
I purposely did not mention repairing the spark plug wire as repairing the resistor high tension leads usually doesn't work. On some ignition coils, which are sometimes called magnetos or armatures, the resistance per inch of the high tension lead varies between manufacturers and the length along with the resistance in the spark plug are critical to correct spark voltage and operation of the coil.
I'm pleased that you slept on it and made the right decision.
I think that you still need to make sure that the charging system is working properly and this needs to be done with a fully charged battery.
As for mice, I have suggested to some folk to get a small tarp to cover the power plant of their machines and get a box of Fresh Cab Botanical Rodent Repellant, 4 bags per box and reusable. Put some bags of repellant around the engine area and cover the power plant area with a small tarp. The tarp will keep the odor of the repellant concentrated in the area around the engine and be more effective. When the machine is used, just remove the tarp and repellant bags, and put everything back after the engine cools down, particularly the muffler!!!!!:cool2::cool2:
Mad Mackie in CT:laughing::biggrin::smile::biggrin::biggrin:
I'm just down Rt. 354 from Colchester
I buy Scag items Ganos