The Joys of Decarboning

No kidding, I had about 1/4 inch of the stuff on my rear piston. Not to mention all the carbon solidly built up around my valves, shrouding the heck out of them, and screwing up valve timing on all the cylinders. Oh the valves worked correctly, but buried in their carbon tunnels, as far as the engine was concerned they opened late, and closed early.

So the joy part of it all was the effect when I was done. Golly gee, but it's like I rebuilt the engine. I hate to think of how little power I was working with before, considering how little I'm working with now!

Now, the tractor doesn't bog down when I engage the hog. When I run into the creek, I can do so with authority (did it twice yesterday). It backfires through the muffler like it means it these days!

Seriously, carbon buildup is a real problem on old worn and cold blooded engines. It's a simple matter to take the head off. Decarboning the engine every few years can go a long ways to keeping it running well. If it hasn't been decarboned in your memory, doing so can result in delightfull improvements in how the tractor runs.

These engines are darn low compression, so it's possible for a bit of paint to hold the head down. Add to that a good head gasket with nice sticky stuff still left, and you could probably run some of these machines for six months without head bolts before the head would finally come off.

What's the scoop on head gaskets? Well, I kinda like them and recommend them. Yea, I've run flat head engines before without them. You gain compression (theoretically at least), but you lose air flow into the cylinder, so you may have a net loss.

Anyhow, that's probably not what you're asking about. Head gaskets these days tend to go on dry. There is just the right amount of sticky stuff on them from the manufacturer. Follow the head gasket makers instructions on using sealant or not. Truth be told, I don't know what New Holland says or what the new head gasket looks like. I took my old one, cleaned things up, smeared it thinly with my favorite ultra copper, and put it back on.

I was kinda surprised to see how the various head bolts go down into the crankcase water jacket or oil area. That would promote leaks. I thought about applying a little bit of goo onto the threads of the bolts when I installed them to help seal them, but I didn't. Just lightly greased them instead. If I leak obnoxiously, I'll do that.

T'wasn't me that gave prices or head skimming numbers. Don't know them, especially for these engines. Skim it if you want, but I don't see an inherent reason to do so. These aren't high compression racing engines, so I just don't really think there's going to be a need of it.

Don't remember seeing it in the manual, but when you reinstall the head, follow the basic torquing path (around the head, starting in the center working out), but do so in incrimental steps. My own is to go first time around just seating the bolts. Second time around to around 10 ft lbs. Third time around to 25 ft lbs, fourth time around to 50, sixth time around to full torque. Wait a little while, recheck final torque values. Takes a little longer, but you tend to get a better result this way.

Btw, Eastwood sells these nifty plastic socket inserts so you won't damage the finish on your nuts and bolts. :-)