Guys, since there are several of you with these kits now, one thing to watch out for that I didn't notice until my report was sent to George and Joel was that the keyway in the flywheel might be as much as 0.015" and 0.020" wider than the gib key. In India-assembled engines, that's no problem because they just slam the keys home with a sledge hammer, sometimes so tightly that they have to be drilled out to remove them. The roller bearings aren't designed to take that kind of abuse, though I haven't heard of anyone who has ever found their bearing were damaged on first startup.
The gib keys need to be fitted to the flywheels so that the heads stand out about a finger's width from the hub. With new gib keys that haven't been fitted, you should plan to spend some time filing the tapered (top) side of the gib key so that it goes that far into the hub. If you just pound a new gib key home, you will only have about 3/4" of key holding the flywheels on which might allow them to come loose. A lot of India assembled engines have 2" or more of space between the hub and the gib head which indicates the keys were not fitted carefully.
The way I fit my keys was to blacken the taper side of the keys with a black Sharpie marker, then slide the key into the flywheel hub until it stopped, tap the head of the key a couple of times lightly with a hammer, then pull the key out and note where the ink had been scraped off the tapered surface. That locates the high spot on they key. Then place the key in a vise and using a sharp mill file (buy a new one if you don't have a _sharp_ file) gently remove the high spot and a little more. Then reapply the Sharpie ink, and check the fit again. It will take some time but you will eventually see that the key will be sliding farther into the keyway with each adjustment and the point of contact should broaden. If the contact point remains a small spot, use the flat narrow edge of your mill file to take any high spots off of the flywheel keyway. It's slow going, but you'll be rewarded by a better fit. I'm sure you could speed up the process by using a flap sanding wheel or even a grinding disk in a 4.5" angle grinder (20 bucks at Harbor Freight) instead of the file, but I used the traditional method.
Now, with the gib key gently tapped into position, stand facing the engine with one hand on each flywheel and rock the flywheels back and forth on the shaft in opposite directions. If your engine is like both of mine, the flywheels will turn a little before coming to a hard stop against the gib keys. If you have a dial caliper, you can measure the width of the keyway in the crankshaft and in the hub, and compare those figures with the width of the keyway.
In my Ashwameigh 6/1, the gib key was 0.009" narrower than the crankshaft keyway, and 0.020" narrower than the keyway in the hub, so as the engine ran, the flywheel was clanking back and forth on the key to the tune of 0.029" which made a horrible sound just like rod knock. Drove me nuts trying to figure out where the noise was coming from. After eliminating everything other possible cause, I finally found the problem was this excessive clearance, but only after a key fell out, nearly causing me to soil my skivvies as I watched the flywheel spinning on the crankshaft with no way to prevent it from walking off the end of the shaft.
The Beta Test engine was better, but still not perfect. The keys fit very tightly in the crankshaft, so tight I had to insert them from the outboard end of the crankshaft and tap them into place with a hammer. So far so good. But the keyways in the flywheels were 0.017" wider than the gib key. Just like my Ashwamegh.
Now, here's the fix. Two words: Brass Shims. Get some pieces of brass shim stock. It's available from McMaster.com in any size you want. Enter "brass shim" in the search box and hit enter and it will take you to a page with some choices. Select Brass Shim Stock and you're there. They have shim stock in many thicknesses. Get two or three sizes for a few dollars each and you're golden, or at least brass-colored.
I found some 0.005", 0.010" and 0.015" shim stock in the bottom of a drawer which was close enough for my needs. A few thousandths of slop won't matter. I cut some narrow strips (appx 1/8" wide and 4" long) of brass using a pair of tin snips. Heavy duty scissors work fine for the thinner stuff. On the Ashwamegh, I slipped a piece of 0.005" brass between the left side of the key and the crankshaft keyway, and a piece of 0.015" brass between the right side of the key and the flywheel keyway. So you see that the shims don't have to be a perfect fit. As I tapped the key into the hub, at some point the key will draw the shim with it, and then as it tightens, the shim will stall out against the side of the keyway and the key will slide past the shim. So you have to withdraw the key and shims a few times and play around with how far into the keyway the shim is placed before driving the key home. The goal is to have the shim in contact with full length of the side of the key. Make sure the key and keyways are clean and free from oil, too. Some say you can dust the surfaces with cement lime (calcium hydroxide, not the kind that tastes so good floating in your beer in Mexican restaurants) or chalk to give the key something to bite into.
Once I had the shims and key in and everything looked right, I positioned the engine so the opposite end of the crankshaft was touching a concrete wall, then I tapped the head of the key several times with a ball peen hammer until it was just snug. No need to pound on it. Just tap it gently until the key stops moving. If the key is fit right, it should only move 1/8" or 1/4" before it's tight. A poorly fit key will just keep going and never seem to tighten up which means you might be distorting the hub.
Happy assembling,
Quinn