Triumphrat

Mecchanica · 03-17-2007

This is a 72, meaning the engine shares oil with the primary. The primary case makes a whole lot more gunk than the engine does, generally, so the 70 and later bikes jam up the sludge trap more often than the earlier bikes, all else being the same.
That link to the hambone who is recommending that you clean your sludge trap without removing the crank should be ignored. Trying that will almost guarantee rod bearing damage. You will force some crud, maybe a lot of crud, into the rod bearing journal and will immediately damage the rod bearings upon startup. Plus, even if it worked, it would take longer to do it than to pull the engine apart and do it right. Those shell insert rod bearings are the ones you should certainly change when you do the sludge trap cleaning correctly. They are relatively inexpensive and will provide good value if you change them. A thorough inspection of the roller and ball main bearings will tell you whether you should also change them. I would, just for peace of mind. Plan on a couple hundred dollars for all the bearings for the crankcase. The cam bushes on the left side usually go high mileage before replacement is necessary, but check them, too. The cam rides on the crankcase alloy on the right, so there is no replaceable bearing on that side.
Also, remove any nicks in the alloy connecting rods while you have them off, and polish them to a high luster.
The engine can make or accumulate crud faster than you can change oil. It can get in via the breather, the air filters, the fuel, and the oil filler, besides that which the engine manufactures on it's own. The 500s have smaller sludge traps than the 650/750s so can jam up with fewer miles. I would definitely pull it down and clean it. The consequences of being wrong about the condition of the trap are significant. A broken rod at high rpm will put a hole in your crankcase, wipe the sleeve off the cylinder, destroy the piston, perhaps bend valves and a camshaft.
Peace of mind is priceless. Especially with a nice old classic which is designed to rev, as is the short stroke unit 500.

So, on to the second half of the question. Yes, you can dive into this pretty easily. Even if you choose to have a shop do the crankcase assembly, you can certainly do the disassembly and removal of the engine from the frame, if you are willing to spend a bit for some tools or can borrow some. You will NEED some sort of half inch impact tool, air or electric to remove the alternator, clutch, gearbox sprocket, and crankshaft nuts. Also the cam pinion nuts, if it becomes necessary to remove the cams from the right case.
You will also need a clutch hub puller, not expensive, and the cam pinion extractor and replacement tool set, IF you have to remove the cams from the case. This will also make pulling the crank pinion much easier. You should also have the primary chain tensioner tool, and a 3/8" BS socket for the head bolts.....most of the rest of your bike will be U.S. fasteners. Get a long handle 1/2" twelve point combination wrench at the swap meet and grind the ring end so that it's thin enough to deal with the cylinder nuts.
A torque wrench, a GOOD torque wrench.
Strobe timing light.
Some common taps to clean out holes in the cases.
Get reproductions of the factory repair and parts manuals.
Plan on changing all the gaskets and seals, including o-rings, and all the springs, including valve springs.
Don't be surprised if the valve guides are worn or loose in the head.
New rings, at least.
New primary chain.
New clutch plates, plain AND friction.
Take a good hard look at the teeth on the clutch chainwheel...all the way around...as you sometimes see harmonic wear on opposite sides, for two or three teeth, while the rest look fine.
New clutch thrust washer.
New layshaft needle bearings.
When you get it all back together, use synthetic oils and you will have less wear and subsequent wear particles in your oil to then build up in the sludge trap.
Make sure you run with air filters all the time, especially in dusty conditions, and perhaps even fit an oil filter on the frame someplace.
When you get your crankshaft out and need specifics on pulling the tube out, let us know and we can talk you through it.

[ This message was edited by: Mecchanica on 2007-03-17 15:04 ]