02/19/10

The CL is very simple and straightforward. No computers or mysterious little black boxes here. Most maintenance is very easy. Unfortunately, the available literature is not too good. The Clymer book is terse at best, and has errors that will leave your valves not properly set. It needs to be complemented by the Honda book. The CB500T manual is a good choice, and can be found on line (in PDF form... see links).

Given the bike's vintage, spare parts are mostly unavailable and, when found, come at stratospheric prices.

• Brakes

• Valve clearance adjustment

• Timing

• Speedometer & Odometer

Brakes

Front shoes are not available from Honda. Rears are, at $100/set. When I initially got the bike, I was surprised at the CL's dismal brakes. Well, it is normal. Despite the front drum having twin cams (i.e. both shoes are leading shoes) the thing hardly stops, compared to what I'm used to. I wanted to confirm that the shoes were making an even contact with the drum surface, and to that end I opened the hubs, cleaned all parts, greased the pivots, and drew lines with a marker on the shoe surfaces. Then I rode around the block using the brakes gently, and disassembled the system again, Examination of the wear on the lines proved that the shoe - drum contact is good.

Marker lines on the brake shoes to establish wear pattern.	A curious lizard visited while I was wrenching.	A curious lizard visited while I was wrenching.

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Valve clearance adjustment

If you follow the Clymer's steps you will have the left cylinder's valves set OK while the right cylinder will be off. Better to use the Honda book for that; its indications are accurate.

The valve clearance in the CL is one thousandth of an inch. Most feeler gauges start at 2/1000. I talked with a mechanic that I trust and he indicated that setting the valves at 2/1000 is perfectly OK, so I will stick to that. I found the index marks on the camshafts to be quite vague, and the manual wasn't even very clear on where to look; see pic below.

Ready to look at valve clearance. Both valve covers off, ignition cover off, and alternator cover off.	This shows where to look for camshaft alignment marks for the intake valves. Note the fosilized mud, cacked there since the early Jurassic...	This shows where to look for camshaft alignment marks for the exhaust valves.		Turning the engine to align timing marks.	This is what the cmashaft alignment marks look like.

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Timing

Setting the timing seems to be a balancing act between moving the individual point plates and the base plate. It seems that you get them as close as you can with the base plate, and then do minor adjustments with the individual points, staying within the point gap tolerance. If impossible, need new points. Clymer discusses only static ignition timing adjustment. It is better here to go with the OEM book (the CB500T will work) and shine a strobe on the thing while the engine is running. It's easy enough anyhow.

To set the timing you only have to remove the points cover and the alternator cover.	This is important information.	Use an impact driver just to be safe. Many of the phillips screws in this area can be difficult to remove. I rather use an impact driver to avoid messing up the screw head.	Strobe on the alternator rotor checking port-side cylinder timing.

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Speedometer & Odo / tripmeter

Honda wants $335 dollars for a new speedo. So you better take good care of the one you have.

When I bought the little beast, the speedo was fine, but the odo and tripmeters had quit a few decades back. Hoping I could fix the problem, I actually embarked on the task of opening the instrument. I was unable to fix it, but learnt a good bit in the process.

BTW, this underscores the issue of properly lubing your ride's cables. If you don't have a cable-luber, get one now. I use mine on my bikes, cars, and aeroplanes.

To open the instrument, go around it 3 or 4 times, gently prying the clamping ring with a flat screwdriver. Pry the minimum amount necessary to pull the thing open. Patience is your friend. (Wow, I can't believe I said that!)	No wonder the numbers didn't move. What on earth happened to this? It looked like it was pulled out of the Titanic wreck.	Close up view of the rust and dirt.	It's a miracle the speedo was working.	There was no (reversible) way to remove the gears, some of which were shot.	To remove the face, twist the needle with gentle fingers against either stop. (For moral reasons I used the max speed stop). When it hits the stop, keep twisting. It will eventually come off. Then unscrew the 2 small screws.
Close the instrument back up with a small FLAT pair of pliers. Slowly go around several times.

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