Electrical issues 7016

[rpickle]

Well, I am just getting into these tractors that I picked-up over the summer. This tractor had sat for quite a while. The mice and previous owners made the wireharness a mess. Took it out and replaced all wires. Before diving into this I read as much as I could find on the subject here. I printed a few different versions of schematics and thought I had my bases covered. Everything is wired and hooked up except I have bypassed all safety switches for the time being. I want to make this run before adding the safety items. It cranks over beautifully. No spark, at first. The PO has added an automotive coil with the + going to the ignition switch and the - going to the condensor on the points. I checks the points and reset the gap to .020 and now I have some spark but not enough to fire it over. Seems like the spark is strongest as I am just backing off of the start position with the key!? Any ideas? Maybe I need to recheck the point gap, since the adjustment of them resulted in some spark. This particular 7016 seems to be a version just prior to the 7100 model. I have found some differences with the way it is wired and with what I have found here. For instance, the ignition switch works like the switch the someone posted for a Kohler engine. If I wired it for the Briggs, the relay never energized. I am wondering if I may still have something not right due to the stronger spark as I am releasing the key. I will draw up the way I have it wired and maybe someone can point out my errors. Rick

[PhanDad]

Sounds like there's not full voltage at the coil when the starter is engaged. Could be resistance in the wiring or bad battery (voltage drops too much when under load). I'd run a temporary wire directly from the + post of the battery to the + side of the coil and disconnect the wire from the ignition switch. Put a volt meter directly on the + side of the coil. If the voltage drops substantially when the starter's engaged, then the battery is suspect. If no voltage drop, the spark should be good and there's too much resistance in the normal wiring. Use the voltmeter while cranking to check the voltage along the path of current flow until you find the problem (wire, connection, circuit breaker, switch, etc). Happy hunting. PS - The ignition switch was probably changed to a "Kohler" type when the coil was added.

[HubbardRA]

If you are using the stock ignition switch for that tractor, and the ignition is hooked to the accessory terminal, that terminal has no voltage when the starter is engaged. You will have power going to the coil in the "on" position, but not in the "start" position. You will need to get a switch from an AC716 that had a Kohler engine with the battery-coil type ignition from the factory.

[rpickle]

Ah ha. That makes sense. I wired the switch like it was a Briggs and it didn't work. Moved 2 wires and it now cranks. I slept all day today and now its dark, so I won't get out to write down what exactly I have until tomorrow. The battery I was using is a replaced car battery. I will meter while cranking. Appreciate the help. Rick

[goatfarmer]

No time to sleep, GET THAT TRACTOR FIXED!:D Hot wire it, like PhanDad said, see what happens.

[D-17_Dave]

If you have some spark but it's stronger when letting the starter disengage then it's a voltage problem. Battery cables could be too small to use a starter/generator as they take a BUNCH of amps. This or a gear starter either one could load the weak electrical system and starve the coil making a weak spark. You could try wiring it directly or simply add a jumper cables from another battery and check the spark. If it's still weak then some heavier electrical wiring will need to be done before you'll have the dependability your looking for. There are some other things that can be done, but that should get you started in the right direction. As always, make sure the points are clean and shiny.

[rpickle]

All good info. I'll report back when I get another chance at it. Rick

[rpickle]

Ran the + wire from the coil directly to the battery. Wow, plenty of spark. It fired up and ran about 10 seconds before sputtering out. I have not gone thru the carb yet. Appreciate the help. I will track down where the voltage loss is when the coil is wired thru the start switch. Rick