20 hp Magnum

[Ronald Hribar 91]

Where would I find a motor overhaul kit for a 20 hp Kohler magnum and please do not send me the the plumbing shop.

[CarlH 418]

Here's an eBay item: [url]http://cgi.ebay.com/magnum-m18-m20-oem-kohler-engine-rebuild-kit_W0QQitemZ2379661845QQcategoryZ3186QQcmdZViewItem[/url]

[Ronald Hribar 91]

Thanks Now I have another problem I have motor completely disassembled and there is no model or serial number to be found on it. Vendor requires this. All I know it is supposed to be a Magnum 20 out of a Sunstar. And $400 for kit makes me wonder if I just shouldn't get new motor with warranty for $1000.

[CarlH 418]

Another member might be able to supply the Kohler model/spec info from their Sunstar.

[Nubian 3]

Hello Carl! I've got 2 motors and 1 in pieces. all came from a sunstar model #1691381 which have the Kohler M20S spec# 49544 in it. Is that a good price for the kit because I want to try to rebuild one myself (first timer) Ed

[Ronald Hribar 91]

Gaskets and Rings run about $150.00

[CarlH 418]

I think I would go with oversize pistons, new rods, and the crank bearings while I was going through one of these engines. It's apart for some reason, I assume a fair amount of hours and/or smoking and/or oil consumption. Al Eden has some observations about why these engines might be blowing a lot of smoke. If it needs rings, I suspect the cylinder bore is egg shaped and new rings won't stop the smoking. I don't have much idea if the price is good or not, just pointed Ronald to a possible source.

[Ronald Hribar 91]

My motor appears to be in good shape, no signs of overheating(aluminum is not discolored) no ridge on cylinder walls. Rings still intact but oil rings are stuck. However I feel as long as I have it apart I would like to put new in. I asked my local lawnmower shop about replacing govenor, he had never heard of problem with them. However many times on this site I have heard of problems with govenor. What should i look for ?

[comet66 0]

If memory serves me...... The gears in the gov. get brittle from heat and desintegrate, disabling the gov. and allowing the engine to run wild and come unglued. I believe they discolor and that is the clue. I have an M20S that came with a sunstar that this happened to. It's a big box of parts. Reguardless, if taking this engine apart I'd replace the govenor components. That seems to be the major complaint I've heard with them. Al posted about it once, (I think)maybe he will chime in again for us.

[ambler 0]

Press in new cylinder sleeves, then you can go with stock pistons and rings.

[Ronald Hribar 91]

Took crank and pistons along with cylinders bonifide Simplicity dealer today. Was recommended that cylinder walls be honed. new rings installed . Along with new govenor. And that is going to be what I will do.

[Al 6]

Hi, The governor is located in the highest point in the crankcase in a small area so the air inside doesn't circulate well there. The result is this is the hottest area in the crankcase. This heat situation was significant as the cause of the governor shafts coming loose in the predecessor KTs, when the engine manintainance was neglected. Also when the engines were used under load at half throttle, (a common engine killer). When the governor gear is new it is almost a cream white. In normal use it becomes a light tan. If it is a dark tan or brownish tan, it should be replaced. Cheap insurance. Al Eden

[Ronald Hribar 91]

The governor is carmel colored. Was going to replace it anyway but this makes me feel better. Have one more question. The stator looks good,was working well. And it did not have debris packed into it. However on magnet is broke and loose. I know exactly how it should fit in place. What should I do? Glue it back in place?

[Al 6]

Hi, Yes. DO NOT TURN IT AROUND ETC. If one has a problem with the magnets, and often all are loose and stuck to the stator. DO NOT REMOVE THEM FROM THE STATOR UNTIL YOU MARK THEM FRONT AND BACK AND NUMBER THEM IN SEQUENCE. THE MUST BE GLUED IN IN THE CORRECT SEQUENCE AND DIRECTION!!!! When I find this situation, I usually take a "Sharpie" tm pen and put 1 line on the back of 1 magnet and then 2 lines on the next etc. Then I remove the magnets and mark them on the inside and blacken the front edge for orientation purposes. Next I wire wheel the glue off the back, then sand out the inside of the flywheel leaving the location outlines. I then use 2 ton epoxy or any good epoxy and glue them in in sequence. One needs to wiggle and press on them a little to "merge" the epoxy and squeeze it out from under the magnets. One cannot leave a thick film of epoxy under the magnet or there will be clearance problems with the stator. That is why I wire wheel the old adhesive off the backs of the magnets. It is not uncommon to have one magnet missing, this is how Kohler made a 15 amp system into a 10 amp system. Just glue them in by the outlines left in the flywheel and leave the gap. I have probably fixed 50 of these through the years and have had no trouble. If you mix the magnets up, you need a different flywheel. Al Eden

[Ronald Hribar 91]

Al Thanks again