Mag 20 PO Mod

[j4c11]

Well, after going to all the trouble with this engine, it decided it had enough and broke a rod. Exactly why, I do not know, first thought was oil, but it was to the full mark with no gas in it. Oil pump works, maybe it was the 2200 hours it had on it. Just wish it had done it before I went through all the trouble to take it out clean it up put a new oil seal and put it back in. No damage done to the block, camshaft or bore. The rods are NLA, only thing available is used ones on eBay. After taking the cylinder jugs off, I saw a lot of deep pitting on the top and scratches I was not able to see before. Seemed like a really bad idea to dump more money into it, was getting ready to pony up for a B&S Vanguard when I spotted an ad on Cragslist for a 1535 with a broken clutch. Sure enough ,the owner was more than happy to sell me the Mag "15" for $250.

It had been sitting for 2 years under a tarp, some surface rust, but it turned freely and had compression. Brought it home, started tearing it apart. Starter is bad, two magnets fell off the flywheel and stuck to the stator, presumably from sitting outside because no damage was done to the stator. Took the heads off, nice crosshatch on the cylinder walls, no scratches, no pitting, looks like it hasn't seen that much run time. Some deposits on the back of the valves which I took care of , valve clearances are within spec, feel like I won the lottery, this thing looks to be in really good shape. The good old Mag 20 kindly donated its flywheel,stator,ignition coil and carburetor. I am unsure of the condition of the ones that came off the M15,They may be fine, but I know the ones off the M20 worked and I don't feel like taking it apart again. Tomorrow it goes into the tractor, fingers crossed it should fire up and give me many years of service. Guess it's a 1872 now

I guess it's true every kick in the ass is a step forward

[J-Mech]

If the "new" motor has no crosshatch still present, I'd say it's got quite a bit of run time. Maybe you worded that wrong?

You can still get KT and Mag rods here:
http://www.psep.biz/store/kohler_aft...cting_rods.htm


My mistake. I thought I saw the right number, but I double checked and I read wrong. I'll keep looking, pretty sure I've found them before, unless now they are NLA even in aftermarket.

[j4c11]

Originally Posted by J-Mech

If the "new" motor has no crosshatch still present, I'd say it's got quite a bit of run time. Maybe you worded that wrong?

You can still get KT and Mag rods here:
http://www.psep.biz/store/kohler_aft...cting_rods.htm

Nope, I said nice crosshatch

That is the first place I went to, no rods for the M20 listed. Rods for the M18 are still available, both aftermarket and OEM. Why the M18 parts are plentiful and the M20 are not, I do not know.

[J-Mech]

I edited my post, I misread the part number I was looking for.... and apparently your post.

I'll keep looking...... now it's a game.

[j4c11]

Originally Posted by J-Mech

I edited my post, I misread the part number I was looking for.... and apparently your post.

I'll keep looking...... now it's a game.

The part number off the rod for the M20 is 52-059-10.There's a couple used on eBay. Others listed as M20 rods but under a different part number, don't know what the difference is, I'd hate to spend $80 to find out it won't work. But, the crankshaft journal is scratched/damaged, and with the cylinders in bad shape, I don't think it's worth dumping money into, it's done its job for 2200 hours, RIP

I'm thinking of buying a couple of M18 rods,they're only $35, maybe a good crankshaft if a cheap one pops up on eBay, put them in a box and be ready for when this one throws a rod in 8-10 years.

[J-Mech]

KH-52-067-71 is the number I found for the rod in an M20.

I hear you about it being shot. I wouldn't fix it either. I don't mess with the Mags/KT's. They are just not worth the trouble. I may try to play with one every now and again, but they are just not a "rebuildable" motor.

I hope it lasts you a long time!! I'm getting scared of mine. It's really racking up the hours.....

[R Bedell]

52-059-10

According to Kohler...........No such number

KH-52-067-71

The New & Correct number 52-067-71S which is NLA

[J-Mech]

I think the "S" is for the .010" undersize rod.....

[R Bedell]

I think the "S" is for the .010" undersize rod.

NOPE.........52-067-72 is the undersized Rod.

[J-Mech]

"S" is standard. That even makes sense. I think I've had enough tonight....

See you guys later.