25 HP Kohler stator problems

[Canadian_Zuk]

Hi everyone, I have a problem I need some advice on. I was out this weekend testing out a new to me Max with the 25 HP Kohler magnum motor when I experienced a pretty nasty failure a few km back into the woods. I was cruising along when I bounced over a small log in the trail and all hell broke loose. I heard some crunchy grindy sounds and the motor came to a stop. After diagnosing the engine in the bush I determined I dropped a magnet (or two) from under the flywheel, this has taken out most of the stator too I assume. I found broken pieces of stator magnet around the flywheel and starter motor after removing the fan cover.


So, my question is in regards to flywheel balance. Would I be safe to remove the remaining weights from inside the flywheel? Are they spaced out evenly or do I need to worry about balance with the weight of the magnets missing? I plan of pulling the flywheel from the motor and removing all the factory charging system components from inside there and I will just run a 1 wire alternator setup but I'm not sure if I should start shopping for a new flywheel or not.

Thanks in advance for any help on the matter.

-Steve

[Nubs]

flywheels are balanced before the magnets are installed as far as i know, i have removed them many times on vanguards in the past.

[Canadian_Zuk]

Excellent and thank you. My local small engine guy confirmed this for me just now, he said it was common for these to even be missing a magnet or two and still run fine.

I will pull the flywheel today when I get home from work and see how much carnage I have. I plan on gutting the factory stator and the remaining magnets from inside the flywheel so I can just run an external alternator. My engine does not have a manual recoil so I will try and find an accessory shaft to bolt on and run the alt on the crank side.

[JoeMeg]

If this doesn't go straight to them,the front drives (for part numbers) are on page 20.

http://kohlerengines.dirxion.com/app.php?RelId=6.4.7.1&bookcode=kea14flx

[Canadian_Zuk]

If this doesn't go straight to them,the front drives (for part numbers) are on page 20.

http://kohlerengines.dirxion.com/app...kcode=kea14flx

Thank you for the link, it confirms the Ebay part I ordered blindly yesterday will work perfectly well for my application. I ended up finding part number 24-755-08s on Ebay, it has an overall length of 7" with 2.5" of usable 1" dia keyed shaft. I can source the pulley from the hardware store once I pick out an alternator. I'm looking for something internally regulated, small, efficient and in the 30-40amp range. I've been looking around for a while and there appears to be and endless supply of options to choose from lol. I want something that runs CCW as viewed from the pulley in order for me to mount it where I'd like. I want to fabricate the bracket right onto the engine stand, but also do it in such a way that it's final position will not interfer with routine maintenance.

Thanks for the help, I have a lot to learn about this machine.

[Canadian_Zuk]

Well I pulled the flywheel and suspicions were bang on, all but one magnet had come free from the flywheel and took out the stator. Everything has been gutted and the motor reassembled, now waiting on my output shaft and new alternator.

[Mike]

Man, that was nasty. I'm glad you got it sorted quickly.

[needcoffee]

If it helps this is what worked for me:

Denso # 18504-6220 is the 40 amp alternator PN. It is a CW rotation. Don't get too hung up on rotation it provides cooling and but not a heck of a lot. I did not have any luck trying to find a CCW in the mini denso size. Go with a 2 or 3 wire type. The one wire has the excitation field always on. Which will drain your battery without a cutoff switch. I went ith a 2.5:1 pulleys. GIving me 10000rpm at the alternator at 4000 engine rpm. The max alternator rpm is 12000rpm.

Regards

[Canadian_Zuk]

If it helps this is what worked for me:

Denso # 18504-6220 is the 40 amp alternator PN. It is a CW rotation. Don't get too hung up on rotation it provides cooling and but not a heck of a lot. I did not have any luck trying to find a CCW in the mini denso size. Go with a 2 or 3 wire type. The one wire has the excitation field always on. Which will drain your battery without a cutoff switch. I went ith a 2.5:1 pulleys. GIving me 10000rpm at the alternator at 4000 engine rpm. The max alternator rpm is 12000rpm.

Regards

Thanks for the reply. I ended up going with a small 37 Amp SI style 2 wire GM alternator. I picked up the PTO shaft from Ebay for $50 and the Alternator cost me $80. I fabbed up a crude but effective mount with enough adjustment to run a wide variety of belt sizes.

[Nubs]

A GM alt will charge turning backwards? I didn't know that

[brushcutter]

Nice, and yes a GM alternator doesn't care which way it's turned. I never considered using the stock system on the Honda in my Trackster. Went with a 2 wire, sent the field from the key switch through a warning light so I know when it is charging , if it is illuminated the battery isn't being charged. It works great and I don't have to worry about a dead battery when I'm winching apart beaver dams or logs out of their ponds. I used a turnbuckle for tightening the belt. also on the battery connections, clean them well and apply either insulating varnish or good old grease, I use grease because mine is an Interstate deep cycle marine and has threaded studs, don't want them gummed up with varnish.

[curtisbyrne]

What alternator would work for my 92 magnum with a kohler m 18 ?

[Canadian_Zuk]

What alternator would work for my 92 magnum with a kohler m 18 ?

Just about anything can be made to work. Your choice will depend on mounting location, power requirements and pulley choice. GM alternators are cheap, internally regulated, easy to hook up, easy to mount and can be spun in either direction but they are bulkier than what you would find on an Import. Most of the small import alternators come setup with sepentine pulleys (these can be swapped to a V-belt). I chose a GM 35 Amp alt, it was new, cheap and sufficient for my needs.

[curtisbyrne]

Send a link of the one that you mentioned,there are so many don wan to get the wrong one! Also how is your alternator working now?

[Canadian_Zuk]

I used a GM 37 AMP 10SI. It's the smallest and cheapest GM alternator you can get.