Topic: Why no spring washers here?

[Deltarider]

My 3 screws have never came loose. Flat washer only.

Same here, but from a mechanical viewpoint, I'm still curious to know. In a normal CB's live, the 3 never have to be touched, because all of timing originates at the breakerpoints. In other words: as long as nobody has messed with it, timing the ignition can be done by readjusting the breakerpoints to their former gap (= dwell). Unless the assembly has to be removed to access the advancer ofcourse.

[bryanj]

True until the contacts wear out

[PeWe]

Yes, if the ignition was properly set to start with.
Use the dwell meter when bikes idle and adjust.
They should wear  so gap decrease, dwell angle less.
Ignition need to be verified to ensure not wrong.
Too late, running hot burning valves.
Too early pinging, risk hole in piston.

I have seen that dwell change a little from cold to hot engine.

[Deltarider]

They should wear  so gap decrease, dwell angle less.

Correction: if gap decreases, dwell angle increases. I admit it's confusing and also I have to think twice.
OEM contactbreakers last very long indeed and require almost no maintenance. All it takes, is drop a drip of oil on that little felt (at 5 o'clock).

[PeWe]

They should wear  so gap decrease, dwell angle less.

Correction: if gap decreases, dwell angle increases. I admit it's confusing and also I have to think twice.
OEM contactbreakers last very long indeed and require almost no maintenance. All it takes, is drop a drip of oil on that little felt (at 5 o'clock).

Yes, you are right I always mix them up despite I know.

[Deltarider]

Mine can get of no problem...

Ahh... well... no, they can't. This Sunday afternoon I had another look at mine and guess what! Couldn't get the flat washers of, just like Bryan said. One of the three heads was battered (by using a non JIS screwdriver in the past), so I decided to replace all three by allen bolts out of a set I had bought at a SOHC Four dealer nearby. It was because the shopkeeper/mechanic had added not only a flat but also a spring washer for each and every allen screw including the three 5mm ones, that my curiosity was triggered. The three crossheads that I replaced today, must be the ones the bike left the assembly line with. BTW, when you go to CMSNL and look for that particular bolt, you'll see it has been superseded a couple of times.
http://shopfourdeel.nl/imbusboutjes-bolkop/72/imbusset-voor-ontsteking-4-cylinders.html