Frustrated with the P218 in my 6018L!!

I do have a new coil and I will install it soon. But it has been my experience that when the key switch is turned to the on position and the spark plugs fire once with some residual fuel in the combustion chamber, this means that the ignition module is starting to fail. The ignition module was replaced with new about 50 engine hours prior and 2 years back. The engine 'dieseled' several times this operating period which tells me that the engine is running very hot. The cooling system is clean and the tractor is not operated in dust and has about 120 hours since and out of tractor decarb and cleaning. Engine oil consumption is 1/2 pint in 2 hours of operation as stays fairly clean, little to no smoke on cold starts.
i am going to drain the 87 octane fuel out and refill with 89 or 91. This will cool down the operating temp of the engine and reduce or stop 'dieseling' or run on after key off.
I did find an on line supplier of 24 Honda complete repower kits for 6018s!!!!! ChaChing$$$$$ 😎

A few things, if you are in a Jam Bob I have parts in stock up the road in Andover CT. and have multiple coils, key switches and spark modules and triggers here currently as of today lol. Sold 4 coil last week so you know how that goes but have 6 left In stock I think, Anyways. As far as the spark module I have had a few test "good" and end up being faulty... can be frustrating. There is very little to the ignition system as you know on the P series. Its been our experience that often these items fail closely in pairs. As you know diagnosing is key, BUT problems that are not constant or definite are tough. So if you are getting key power where and when you should, Coil tests good and spark Module test good. Then this is what we do and recommend for a couple reasons. Replace the key switch and coil, They are the eaisets to deal with and least costly. If that does not fix the issue then you are left with module and trigger. Like I said most times these fail close to each other and we feel one causes the other. To me to protect the invest of the spark module and or coil its a no brianer to replace the switch, coil and spark module and trigger. Not cheap but cheaper than wiping out a part you just put in and much easier and less aggravating than having to pull engine again to replace the expensive part again. Just my 2 cents.

As far as vapor lock, we see it very often in the spring especially with left over winter gas and especially low test. We run and recommend high test 93 plus octane in everything and non ethanol if available. Many times fresh high test fixes the issue if there is not a true over heating condition. 3 tell tale signs of vapor lock are when it dies sometimes you can hear the gas boiling off, sometimes clear fule filter is empty or bubbling and 1 almost always sure sign pull carb top off right away and it will be empty. Good luck

Hi dundee222,
The housing is pot metal and the crimp breaks. The switch had a 1999 manufacture date on it, so it was due, the machine was built in 1998 probably as a 1999 year tractor. July 1997 build date on the P 218 Onan. I have an analog voltmeter in place of the stock ammeter and I noticed that the charging voltage was higher with the new switch and regulated to 14.3 VDC quickly. The charging voltage with the old key switch was slow to come up to 14.3 VDC, so there was a problem with that switch. In my stash was a new switch that I had labeled to go on the 6018L in 2019, I had forgotten to install it when I repaired the electrical wiring. I just used the tractor to move around some metal junk in my woods. I need to rent a dumpster and get rid of this junk, transmissions, engines, about 8 of them and broken boat trailers! I'm going to keep a pair of neon spark testers under the seat just in case. 😎