Rebuilding my 100

[litlmikeyl]

Some new pictures of my machine. I found some cracks in the frame where the front axle mount is too, so I posted some pics of those as well. Looks like someone had tried to fix the crack before, but it split again where it did before.

[Matt G.]

That's a common area to see cracks on a NF. Stop drill the crack, and then weld it back up.

[cubs-n-bxrs]

You need to grind out the crack as well as drilling holes at either end of the cracks. Small drill holes at either end of the cracks will prevent the crack from spreading. When you re-weld the area you will need to grind it back flush so the motor sits back in the frame level. Otherwise the oil pan could possibly break and you will also have alignment issues with the drive shaft. Bottom side of the frame does not need to be ground smooth. Just did that repair on my garage sale 122 this past summer.

[litlmikeyl]

Was able to weld up the cracks in the frame (thanks for the stop-drill idea guys!) and ground those smooth again. Also got most of the way thru the axle pivot pin before I ran out of batteries in my drill, which is when I shifted over to the motor. Pulled the head off (it smoked a bit when I parked the tractor in the fall) to see what kind of shape the insides were in... only to find grooves in the cylinder wall on the exhaust valve side. They aren't too bad (I think), maybe .010" if I had to guess, and everything else on top looks good. Lots of carbon though that seems par for the course given the age. The cylinder bore measured between 3.245 & 3.248" dia. which answers my question if its a K241 or not (my tag is in awful, unreadable shape) and that it must be a "virgin" block meaning it hasn't been cut yet. The motor does roll over really nice, I mean REALLY nice, and smooth with almost no endplay in the crank & block. Think I'll focus on the motor next since I can do other work while its out getting repaired.

Any idea on what it might cost to do the machine work? I have the tools to do the teardown/rebuild, which I'd like to do, and only have someone else bore the cylinder & cleanup the rod & crank if needed. Does anyone know of someone around the Minneapolis area (or outside within a few hours drive) that I can trust to do the machine work? I'm a bit skiddish about someone doing machine work and it ruin the poor motor in the process.

But most importantly, new pictures to share.

[Methos]

If it's been bored out it would have a stamped .010, .020 or .030 right on the top of the piston. You could see it once you pulled the head off. Without that stamp it still has the factory piston in it.

[young enthusiest]

you said you saw a lot of red pain on your engine. seems as how it does not appear to be the stock engine, I am going to assume it is out of a Wheel horse. they had a red that looked like that, and as far as I know, used the same type of engine. I'm guessing that the PO just spray painted the engine black without stripping it apart, leaving some red in hidden places that you are finding. just my guess. anyone else think the same? nice work BTW, cant wait to see it done!

[Matt G.]

That red sure looks like somebody went nuts with a rattle can to me. The flywheel would have been unpainted from the factory.

[Mike1450]

To answer the cost of some block work. I rebuilt my 14hp last year and had machine work done.

To do the cylinder 10 over was $46
Valve job $36
Turn Crank pin under 10 $45
Head resurfaced $20

The shop gave me the measurements before and after the work. It all fit together nicely. She has 63 hours on it now and runs like a top!

[litlmikeyl]

Mike - Thanks for the figures from your machine work. Puts me at ease that maybe it won't be terribly expensive to get the work done to the motor.

As for the red paint... it's easiest to see on the motor. The red isn't everywhere on the block, but it covers at least 85% of the motor. The rest of the tractor has the same red paint hiding under the yellow coat that you see. This is the order of colors found thus far:

Bare metal -> Stock IH Cub Yellow -> "THE" Red -> Lighter shade of Yellow

It isn't a primer as far as I can tell, so who knows what the deal is here. I was more concerned with the color for what young enthusiest said, that it may be a motor off a Wheel Horse. I want to put the correct parts in/on the motor so it works correctly for my Cub. I don't know if there is a difference between a Wheel horse motor & an IH motor.

As far a picking a shop to do the machine work, as newbie as it sounds, is there anything in particular I should look for? Any specific questions I should ask?

Thanks everyone for the help so far.

[Matt G.]

Wheel Horse blocks probably use the wide oil pan, so that's not possible. From the order of the paint you posted, it sounds like some PO with a spray can did some 'customizing' at some point. I'd quit worrying about it.