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As per my last post,Ashtabula was the focus and Gadget made her debut there. Now it's time to figure what sort of devil got into my Kohler M-18. Here is the scoop. About 20-30 min into the "Maiden Voyage" at Ash in June,began experiencing what seemed like a fuel problem. I know the carb is less than perfect and has some issues in the low idle circuit which would support this. I made the decision to park it and just use my Argo for duration of the weekend. Having just put 2-3 of the 5 gallons of fuel I brought in the Attex,I figured I would just drain it back out and put all in the Argo. Pulled fuel line from pump and could not get a flow out of the line. Once home and aided by 150 psi in the compressor,still couldn't get any flow. Blew through backwards and shazam now things are happening. Plugged fuel line?!? No way,brand new everything,first time running,no way but ,yes it was blocked and I don't know how or why but now have flow. This further reinforces the fuel delivery problem thought to be occuring. However,machine still won't idle. Installed my spare carb (that I didn't have at Pine Lake) and she fires up and idles like a champ. I'm happy. Make trip to my property (with my very critical quadding friends) get out in the woods and 10-15 min of riding begin getting what seem to be the exact same symptoms,hobble back to camp. Try to start to drive on trailer (using winch for this is getting old) and won't even fire w/ether. Put spark tester on and see I now have very little,very weak spark on both cyl's. So,out it comes tonight for some disassembly,to be continued....
I have installed a new starter motor on the Kohler. Next I'm going to rig the plugs to check the spark. If I get good spark I'm going to begin heating up the magneto slowly to about 200/250 deg. F. all the while checking the intensity of the spark. If,upon heating,the intensity of the spark begins decreasing I will swap out with a spare and perform the same test. If heating does not affect the spark then I will and very reluctantly assemble and re-install it. I will then test it out with all the same stuff expecting a different result. I'm pretty sure that's one of the symptoms of insanity. To be continued.........
Joe, Do you have a Megger that you can borrow from work? It will tell you if the insulation is breaking down in the coils. Also try a resistance check from your spark plug lead to ground. Should be 4-6 kohms on a good coil. Less resistance on a shorted coil.
Lance,yes I have access to a 500/1000V MegOhm meter. The svc man say's the resistance between the two plug leads should be 22-42K. I'm getting aprox 36K with a high impeadence VOM. Seems ok. Wasn't sure if megging it to ground was a good idea but I guess it's just a couple balls of wire in there,correct? Manual also show very sketchy pic of testing the primary but fails to offer any values or a specific connection to perform this test. I would think lead to ground but I have plenty of other problems w/o adding assuming to the mix. Thanks for the input. I'll let ya know what I find.
OK,here is what I did. First I googled "Test Kohler M18 Magneto" and read a half a dozen threads on the subject. Didn't really get anything "conclusive" but gleaned a little more info on a few things that make sense and I never thought about. One of which being related to cranking speed as a result of the condition of the starter motor (interesting),battery,etc. Keeping the megohm meter as a last resort,I sanded the "face" of the magneto poles nice and clean,did the same thing to the magnet on flywheel. Manual has illustration of gap being .008-.012" but if one reads,it says to set the gap at .014" claiming there is enough deflection from the pull of the magnet for the actual final gap to be correct,OK,so I gaped it at .014". I clamped the spark plugs to the engine and connected the leads (both of them!). I then hit the (new)starter w/12V and man did that baby begin crankin' and spitting fire at the plugs! Then I installed spare set of plugs in engine to add compression to the mix and slow the crank speed. Still sparking real nice. Began heating the magneto til it was pretty darn warm and still sparking real nice. Put the covers back on and started the engine,fired rite up! Ran it for about an hour total,shutting off,letting sit 2-3,5-10 mins at times and no issues. The thing fires in what seems to be about one rev,seriously,the key needs only to be "bumped" and we are up and running. So,my conclusion of the whole ordeal,nothing real substantial,just think it was accumulated small issues that just added up to one big one. The only things I really "did" were cleaning the faces of the magnet and magneto,setting the gap at .014" and (what I thinking was the biggie) replaced the starter motor.
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