More Bores...

 Probably boring to non-gear heads, the saga of the chrome bore replacement continues. After dismantling the engine (noted in previous post), cleaning the cylinder head and valves was the next step. I tried using carb cleaner and a brass wire wheel on them, with only modest success, so I called a local machine shop about cleaning the parts and they said $150/hr for hot tanking and bead blasting. So for that much, being of thrifty Bohemian stock, I figured I'd do it myself. Checking ebay, I found a sonic cleaner big enough to fit one head for $120, post paid. So I ordered it and it got here in a week. Sweet. In went the head and valves and after a couple of cleanings, they looked a lot better.

So here it is bubbling away in the sonic cleaner. One head and two valves done in about half an hour. So I decide to do the other side, pull the head and valves, and the cleaner doesn't work. Turn it off and on few times, nothing but the fan running, no bubbles. So I let it sit awhile, then try again, and it works. No idea why, but got the other head and valves cleaned. Had to touch up the area around the exhaust port on both heads with the sand blaster, too much carbon build up for the cleaner, but then they were done. The problem with the sonic cleaner is a conundrum. The manual offers little help, other than a brief note that if it overheats, it automatically shuts itself off. So apparently it went into auto-shut off mode and didn't return to operating status for awhile. Anyway, will be getting ready to put the new cylinders and pistons  on the engine, that'll be fun.

The cleaned head and valves, I should have taken a before photo.

Not a professional quality job, but good enough to keep the old Guzzi going for a few more years.

Blue Bores...

 I've posted before about the problem of chrome lined cylinder bores in the older (60's and 70's) Moto Guzzis (Chrome Bores Part 1 & 2). Most mechanics who are aware of the problem recommend replacing the cylinders. There were none available for years, but recently a cylinder and piston kit came out, so I bought one. That was the easy part, now it's time to replace the old parts. With the help of a neighbor, was able to get the bike up on the lift table, secure it in the wheel vice, and put on a ratchet strap for extra stability. Surprisingly, the head and cylinders were fairly easy to remove, following the directions in the ubiquitous Haynes motorcycle manual.

So after removing the cylinders, got out a flashlight and did a visual inspection of the cylinder bore. To my relief, there was no pitting or flaking of the chrome lining, so the rest of the engine should be free of damage from ingesting chrome flakes. While that's good, then you have to  wonder why there's the urgent need to replace the cylinders. Better safe than sorry, I guess you'd have to say, and cheaper than a complete engine rebuild, if the flakes did get into the wrong place.

The clean cylinder bores, looking ready for another twenty thousand miles.

So then it was time to disassemble the head. Had to dig out the old valve spring compessor that I bought many years ago to work on Triumphs. Fortunately it fit the Guzzi head, but it was really hard to turn the crank to compress the springs. After wresting with it, found a short piece of pipe and slipped it over the handle on the compressor and it was a lot easier to turn. Occasionally gave it a tap with the rubber hammer, but nothing would release until suddenly, the collets popped out with a bang. Big surprise, then had to look around to find them. One was at my feet, the other about six feet behind me, apparently it flew over my shoulder. Was pretty happy I found it and it didn't hit me in the face. So then did the other valve and springs, no drama this time, it came off just as expected. Then I sorted all the parts out into separate containers, and put the tools back where I'd find them. When I was finally finished, I noticed an odd smell, like solvent or cleaner. Kind of odd cause I hadn't used any on the engine, though it did need it. Looked all around the garage and couldn't find anything leaking or spilled, so started to leave when I notice a puddle on the floor. I touched it and it was blue paint. Now that was odd, but there was an old can of blue paint on the shelf there, so I picked it up and took off the cap. No, it wasn't leaking, so put it back and looked around some more. Then I stepped outside the door, didn't see anything, but when I looked back inside, I could see a very faint mist coming out near the bottom of the spray can. I took it outside and in the light, could see a tiny dent and pin hole in the can. When that split collet went flying off the valve springs, it must have hit the can of paint hard enough to puncture it. So while it did make a mess to clean up, I was doubly glad it didn't hit me first. That would have hurt!

Later on I noticed that the blue paint had sprayed a thin line across the front of my old Partner hat and into my hair. Gives me that new age, with it look!