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Obsessive_AC_912H

Introduction and Question

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Obsessive_AC_912H
Hello. My name is Tim and I'm addicted to Allis Chalmers tractors. I've had several AC farm tractors over the years, but just recently bought my first AC garden tractor...a 312. It doesn't run and has no deck, but I figured it was a steal for $25. Soon after, I bought my second, a 912H that was supposed to be for parts. I knew that the 300 series was kind of odd-ball, but thought I could get enough parts from the 912H. After I picked it up, I decided that I liked the 912H better, so that is the one I'm going to fix up. Anyway, this bring me to my question...which engine should I rebuild? They are both Kohler K301's, but the one from the 312 is a breakerless engine. It seems pretty worn and has a small hole in the center of the piston. The one from the 912H has points ignition. The bearings seem tight, but one of the balance gears came apart completely shattering the piston. Since I only have funds to rebuild one at this time, I want to make a wise decision. Any help will be greatly appreciated. I have another issue that I can't seem to resolve. The rod out of the engine from the 912H is cast with the number 47 059 07. I have searched and I can't find that part number from Kohler. I don't know if they just changed their design, or if this rod is a special "strong" one, but it has studs to hold the end cap on instead of bolts. I don't know whether to trust it or not, but would definitely like to find another like it for my rebuild. Thanks!!! Tim

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3314WV
I agree. The conversion kits for the older ignitions makes the points debate a moot point ( no pun intended). I would pick one, bore it .020 over, put a new slug in it and be on your way........welcome to the club :)

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HubbardRA
I still like having the points, condenser, and coil on the outside where it can be worked on. I may be old fashioned, but I don't like pulling an engine to fix an ignition problem. I try to keep extra parts and am very happy when I can get my tractor running again in an hour or less. I would use the 912 engine with the external coil. Bore it .20 oversize and buy a .20 oversize piston. If the original rod in one of the engines is not within spec, then get a new rod. Check the crank for wear to determine if the rod needs to be undersize. Use the balance gears out of the 312 engine, and put it back together. Nearly all the parts should be interchangeable between these two engines. This is my opinion which is most likely different than the way others would do this job.

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goatfarmer
quote:
Anyway, this bring me to my question...which engine should I rebuild? They are both Kohler K301's, but the one from the 312 is a breakerless engine. It seems pretty worn and has a small hole in the center of the piston.
I HATE when that happens..... To me, it's six of one, half dozen of the other. Breakerless is nice, but points are reliable, and inexpensive. I'd go with the one with the best bore, that needed the least amounrt of $$ to get it going.

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Obsessive_AC_912H
Thanks for the replies! I had actually thought about combining parts form both engines to get one that would use either points ign. or breakerless. Kind of the best of both worlds. My question was more about which block to use, though. I don't know if I should be leary of the block that had the exploding piston or not. Both show some wear in the cylinder, but nothing that a .010 or .020 bore wouldn't help. And, I'm still confused about that part number on the rod...

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rsnik
Rod, I always convert to a points eliminator simply because I can't afford the points and condensers anymore. Jack's gets $23.88 for the points, $9.95 for the condenser and $7.95 for shipping and handling, which comes to $41.78. Ouch. I just bought a Magna Fire 2 points eliminator online for $12.99 instead of replacing the points and condenser on the Landlord 101 I got recently. I have no history with this brand so I don't know if the timing can wander during high heat levels. I installed a Nova II on the Baron years ago and that tractor gets used hard and runs good, with no issues. BTW, don't buy a Magna Fire 2 from Jack's. I needed another one, was in a hurry and grabbed one from Jack's the other night. The price was $23.54, plus the $7.95 for shipping, for $31.49 total. It arrived in a Stens box. Inside the Stens box was the regular, little white box with the same part number as the one I paid $12.99 for weeks ago at another web site (440-465) and it was, indeed, the exact same part.

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sammiefish
Im not sure the nova or magna fire will work on these battery ignition kohlers my very limited research tells me no. Im very interested to hear if it will work on either the breakerless or points ign K series

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HubbardRA
Jonathan, You can't eliminate the points unless the engine has a magneto. Most of the old Kohlers do not. To me, the cost of the points and condenser is insignificant compared to the time and labor it takes to remove the engine and replace a bad magneto. At least with points and an external coil, I can be running again in less than an hour, even if I have to replace points, condenser, and coil. Every B/S that I have converted to battery-coil ignition has had a bad coil, and I didn't want to remove the engine and take the sheetmetal off to fix it, or did not want the tractor down till I could order the right coil to fit the engine that died. Battery-coil engines start easier than magneto engines, because the slower the engine is turning, the more fire you have. They run basically the same at WOT. A new set of points and condenser usually lasts 20-30 years, so the cost is insignificant to me. That is unless you make the mistake that many make and install a not ballasted coil. In that case the points will burn up in a relatively short time (a year or two). It all depends on what you know, what you want to work with, and how long you want your tractor down when something goes wrong with the ignition. Everyone has to make their own decision. There is no single answer that is perfect for everyone. It is not a matter of right and wrong as most people would lead one to think.

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rsnik
Rod, I own one tractor, a '92 Sovereign 18 that has a Kohler CH18S. It does not have points. All my inventory of engine spare parts are for cast iron Briggs, so I would never buy a tractor with a Kohler that does have points. All my experience with points is bad. The condenser poops out and the points start growing spikes or pitting or the points plunger has wear so the points wont hold adjustment etc. I have never had points last 20 years. If memory serves they seem to last about 20 minutes. I will not have them on any Briggs engine on my tractors. My 2010 actually has had the flywheel repolarized by Briggs and has post '82 style Magnatron ignition installed by the PO. I think a points eliminator works about as good for $12.99. Converting to battery ignition has cold weather advantages which synthetic oil easily handles but at least it is not pointless; you are still stuck with those danged points. You like, favor and enjoy points which I think is admirable. I spent many years adjusting points and do not want points any more but I think it is very charming in a traditional way and great that you still like them. It is the only "point" of divergence in our tractor philosophy; I also maintain my tractors well but don't fix anything that does not need fixing. Major repairs can generally be described as hillbilly engineering with used parts bought cheap a long time ago. And yet my tractors, while used hard, hold together and last. I come across new condensers in my parts inventory which predate the time when I went through the 12 step program to become "points free". I would gladly send them to you although if yours last 20 years there's not much "point". Actually these were probably made in China and you would be lucky to get 20 minutes use if they work at all. :D

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rsnik
Rod, He, he, I can't believe this. The 101 quits running today. I get my spark checker: no spark. I completely and carefully redo the entire install of the Magna Fire points eliminator. No spark. C I reinstall the points and condenser. Starts instantly and runs like a red tape. :O Well, if the 101 likes points it can run on points. At the end of the day I'm going to have to walk that one back about not having a Briggs with points! :o)

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HubbardRA
Well, Jonathan, now you see that I am not completely stupid in my opinion about points.sm01 All four of my currently running tractors have points, but two still has a magnetos on them and one has a Kohler which never had a magneto. There is only one B/S that was converted to battery-coil ignition and I did that over 25 years ago.

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