The correct method is to replace the flywheel should the magnets be loose. I've seen the magnets chew everything to bits to causing no damage at all. Some will epoxy magnets back on, but I never have. The risk for big damage is there. I had a single a couple of weeks ago that had 1 VAC output that I had briefly flashed the 12v over to the AC and it charged and stayed that way so far. Never expected it to really. Figured I needed a stator. May yet. Other than that, it comes apart.

So now I find out it's a horizontal shaft engine. Different service manual. maybe different tests for the module. Do we have to guess how many cylinders? That's 2 different manuals. Maybe if you provided better details, you wouldn't need to start a 3rd thread on the same problem. "I replaced the coil because all the professional opinions suggested it, even though it had spark." Who suggested that? "I thought about checking the flywheel key, but the conditions under which the engine malfunctioned didn't indicate it." Yet several people suggested that! You even said in your initial post, after listing all the TRACTOR numbers, that it appeared to be a timing issue! Personally, I'd pull the valve cover(s) and make sure the rocker arms/valves are functioning properly before I went any further.

Lawn and Garden tractor batteries usually come in 4 different ratings - all in the same sized battery case. Ratings are approximate. 180 cold cranking amps 230 cold cranking amps 300 cold cranking amps 340 cold cranking amps Batteries that are vented through removable battery caps are likely to develop corrosion on the battery terminals. The sealed batteries are vented differently and do not develop the corrosion on battery terminals. Sealed batteries are usually higher priced than the batteries with the removable caps. With the larger engines such as your 25 hp Kohler, the 300 or 340 cold cranking amp battery has more capacity and will most likely last longer than the batteries with lower cold cranking amp ratings. If your tractor runs out of fuel, the higher rating battery will crank the engine longer to pick up fuel. The lower rating batteries are more suitable for the single cylinder engines. Concerning the sealed versus non sealed batteries, would you rather have a battery that corrodes or a battery that does not corrodes - but costs an additional $5.00?

There's a good chance that you don't have an engine problem at all, but a safety switch issue. Post the Sears 917.xxxxxx number so we can look at a schematic and give you a good test procedure. In the mean time, make sure the seat switch is fully plugged in, and any PTO/attachment switches are fully disengaged. Edit- I looked at my homemade data base with the tractors using that specific engine. (doesn't mean I have all of them) The model#'s were pretty much 917.2710xx with the xx being between 10 & 24. They all in common were equiped with 2 OPR's (Operator Presence Relay) IF OPR 1 isn't getting power through the seat switch, the kill wire will be grounded preventing spark. You can do a couple things to test- FIRST- With the key in the ON position, load/unload the seat. You should hear the carb fuel solenoid & OPR's CLICK. IF NOT, you aren't getting power through the seat switch. Temporarily jump the seat switch to prove/disprove. IF it now works, seat switch is bad, making poor contact in the connector or needs adjustment. This post was edited by bill_kapaun on Sun, Jun 30, 13 at 16:17