It's all about Zhongshan people!
Made some progress on the rebuild over the long holiday weekend. If you're really bored and honestly have nothing better to do with your time, you can waste a few precious minutes of your life by looking at how I get my groove on.
Set the #1 timing mark to "T" (Top Dead Center. naturally). Note that Honda considers the rear cylinder, which is what I'm working on, to be cylinder #1. This must be correct before you start to disassemble the drive train, otherwise the camshaft will be under tension when you start to unbolt it and this will cause damage. Avoid!
If the timing mark is set correctly, then the cam sprockets should be in the proper location. Check this up top. See the mark on the sprocket? This has to be precisely in line with the top of the cylinder head. There are four such marks, one for each sprocket. If one of them is out by even a little bit, you'll be in a world of hurt when you try to start the engine later. My marks are good on disassembly, so I must make sure they are back in the right place when I bolt it together later.
Here's the chain woven into the tensioner, which must be taken apart. That means removing the cotter pin. These things can be stubborn and fussy to take out without causing damage to other parts. Here, I'm using stainless steel wire threaded into the eyehole of the pin. Give it a strong pull and you're free. Works a treat, without damage.
With the cam chain free, you can pop off the head with a few raps of the rubber mallet. Here is the bottom, along with the old gasket. Gasket came off in one piece, which I take as a good sign. That tells me the engine didn't get too hot in the past. The cylinder dome is dirty, as expected, but no sign of scorching.We'll clean this up later.
Now it's time to start removing the valves from the head, for which I needed that specialty tool. And here it is in action:
Basically it's just a big "C" clamp, with changeable fittings to match the diameter of your particular valve. The bottom side, which you can't see here, is holding the face of the valve in place. On the top, you turn the crank to compress the valve spring. This releases the spring so you can take off two retaining clips. With the clips gone, the valve is free to slide out.
Here's the head, with one valve out. Note that the deck has been cleaned using fine emery paper and kerosene. The valve seat, along with the vavle itself, will also be cleaned with very fine wet/dry paper and solvent. In my case, I used #2000 paper to get some fresh, shiny metal. Make sure to put the valve back in exactly the same hole that it came from, don't mix them up!
All four valves are out, and the seals replaced. But now I must wait a few more days, until I can get into Hong Kong and buy a new gasket. Once we've got the gasket in hand I can bolt it all back together. Also, still waiting to get metal parts plated separately, which can take a while. More in a few days, I know you can't wait.
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