How to needed for Ignition Module replacement re 4018

[Ray_McAvoy]

Will it damge module if you test ohms to ground on each module lead?

I can't say for sure whether or not that would risk damaging the module. But I don't think it will provide you with any meaningful results. The module uses a transistor (instead of points) to switch power on & off to the coil so it has to be powered on in order to function. And trying to test a powered on circuit with an ohmmeter will often give meaningless results along with risking damage to the meter.

The test procedure from the service manual that Nut Case mentioned is fairly simple. It says: "Connect positive side of voltmeter to negative (-) coil terminal (larger diameter of the two threaded posts) and negative side of voltmeter to engine ground. Turn key on and rotate flywheel slowly by hand while observing voltmeter. Voltage should switch between battery voltage and 1 - 1.5 for each revolution. If voltage does not switch properly, replace ignition module."

[MrFixIt]

I just towed tractor into garage from equipment shed. Will do the test Ray just to make sure.

[Jancoe]

Here is something out of one of my service books. Hope it helps you.

Sent from my SM-G975U using Tapatalk

[Nut Case]

I can't say for sure whether or not that would risk damaging the module. But I don't think it will provide you with any meaningful results. The module uses a transistor (instead of points) to switch power on & off to the coil so it has to be powered on in order to function. And trying to test a powered on circuit with an ohmmeter will often give meaningless results along with risking damage to the meter.

The test procedure from the service manual that Nut Case mentioned is fairly simple. It says: "Connect positive side of voltmeter to negative (-) coil terminal (larger diameter of the two threaded posts) and negative side of voltmeter to engine ground. Turn key on and rotate flywheel slowly by hand while observing voltmeter. Voltage should switch between battery voltage and 1 - 1.5 for each revolution. If voltage does not switch properly, replace ignition module."

That's the procedure I used a few years back to test a module. Thanks for posting it!

[MrFixIt]

I hooked it up to my fluke per intructions. Battery rest voltage with key off is 12.6. (Jancoe I couldn't find my test light..I know it here somewhere)

Hand rotating with socket rachet shows voltage going from 7.8 to 12.4. I hooked up my inline sparker type tester and cranking motor over does show a very weak spark being produced. For reference I hooked up my running 3018 same motor and that produced a strong visible flash/spark. The funny thing is now when I switch key on and test at + - on coil to ground I no longer get voltage drop on both poles as mentioned in first post(1/2volt on the small and 2-2.5volts on big terminal to ground). They both read battery voltage.

I have the 4018 sitting in sealed garage with has a dehumidifier running and will take it down to 45%. Will be interesting if visible voltage brighters at test in am.

Maybe its a coil or condenser.

Edit.. It probably would be ing module as voltage is suppose to drop to 1 -1.5 volts not a change of 1 - 1.5 volts. That collapse in voltage is I think what the coil uses to produce a big spark. I noticed on 3018 when i cut switch off the sparker shows an outsize spark produced at kill.

[MrFixIt]

......Delete

[k0jdd]

Unbolt the engine from the frame first to allow you to jockey it around a bit. Then remove the four Pump adapter bolts.
Put it back to together in the reverse order.

Yes, it is a PIA but it can be done. I had to do it twice in 24 hours once.... But let's not get into why :(

Removing the cooling screen from the left side of the dash tower might give you some more visibility and a place to put your work light. (But you probably can't get a hand in through there to work the bolts unless you are 5 years old)

[MrFixIt]

Thanks kojdd... I went back at it as it was the most pratical way to remove. Difficult on the last to hold crank still while loosening the final bolt. Ended up with small piple wrench on coupler to steady. Now on to removing flywheel. The shroud is tricky.

Edit. Removed flywheel with help of large three jaw puller. Removed stator and ign. module.

I ended up leaving engine on frame rotating it 90 degrees. Not wanted to mess with my back picking it up onto workbench. Only complication was removing throttle cable and hood.

[myerslawnandgarden]

Eric,

The flywheel bolt is standard RH thread, an impact wrench will work fine to remove it but do not reinstall the bolt with an impact as it is too easy to over tighten the bolt and with a tapered shaft the results are not pretty.

Bob

[k0jdd]

... do not reinstall the bolt with an impact as it is too easy to over tighten the bolt and with a tapered shaft the results are not pretty. Bob

Bob is correct of course.

Also make sure the tapered shaft is absolutely clean and dry -- no oil, no grease, no moisture, nada -- otherwise you run the risk of cracking the flywheel with even a manual torque wrench. Been there - done that.