Best way to "Reference" Removal of Bean Can

[Red_Hen]

Hi Gang,

I plan to remove my bean can and replace springs, clean & lube the shaft, over the winter.  Is it okay to blow a low PSI of compressed air in there?

Besides taking a digital picture, before taking it off, any other suggestions for marking the current setting so the timing isn't way off when I re-install?

[Bob_Roller]

A scribe mark on the can and the case so you most likely won't have to do any timing adjustments when you put it back on .

[Barry]

Other than making a mental note of where the screw is positioned in the slot I don't bother marking the position as I always check the timing statically when I put the bean can back on. Mine is a points type can though so that is an easy check.  It's probably better to mark the position of a hall effect can as a static check is not usually done and you would go straight to a strobe check.

As regards blowing out the inside of the bean can with compressed air. It has been suggested that the typical oil impregnated felt used to lubricate the previous points cam was omitted when the bean can was introduced as there was enough oil mist around inside the can to act as a lubricant. If the hall effect type of can is anything like my points type can that suggestion rings true as I find a fine coating of oil on everything so compressed air is not likely to be that effective.

[rwait]

Not answering your questions, but be sure to replace the large rubber o-ring on the back of the can before you put it back in....

Randy

[montmil]

I use a Sharpie felt tip marked. A small dot on the bean can flanges and an adjacent marl on the timing chain case works just fine. If desired, a quick swipe with a rag and some carb cleaner removes the marks. I wouldn't suggest scribing marks in the metal as they may be confusing some day down the road -to you or someone else.

Keep in mind the issue of parallax when viewing the marks. You'll need to have your Mk1 eyeballs in the same spot for refit.

The Airheads are pretty tolerant of slightly out of time running. You need not worry too much.

Monte

[Red_Hen]

Thanks, Guys

I have a strobe timing light, to time the bike.  Monte already suggested repainting the timing marks, which I'll do - thanks, Monte.

I know we're supposed to not attempt to balance carbs until bike is really warmed up - does the same hold true for setting the timing?

[montmil]

Thanks, Guys

I have a strobe timing light, to time the bike.  Monte already suggested repainting the timing marks, which I'll do - thanks, Monte.

I know we're supposed to not attempt to balance carbs until bike is really warmed up - does the same hold true for setting the timing?

Yup. The engine may run "funny" during or after the timing adjustments if it's not at normal operating temps while playing with the strobe light. A fan blowing across the engine is not a bad idea, either.

It's an easy chore and it makes you feel good when it's completed. Snug the bean can but allow some movement as you tweek it one way or the other. A final snug up, then check the timing one last time.

Careful of the hot exhaust pipes!

Monte

[Barry]

I know we're supposed to not attempt to balance carbs until bike is really warmed up - does the same hold true for setting the timing?  

I suppose ideally the engine should be warmed up enough to run cleanly but no way is this as remotely critical as setting the carbs.  Certainly no need for a 10 mile ride or anything approaching that.

To be realistic there's no point in having a fully warmed up engine only for it to cool down while you remove the battery earth lead, take off the front cover (and a bit of skin on the hot pipes), then put the earth lead back before you even start setting up the timing light.

Checking the timing on a hot engine is one thing adjusting it is something else. I'm a fan of static timing it's so easy on a cold engine with points. If I had the hall effect type of bean can I would devise a means of setting the timing statically and only check it with a strobe on a hot engine.  I understand this can be done as there are several LED circuits around on the net for just this purpose.

Setting timing statically means being aware of the possibility of worn advance mechanisms and the advice that it's only the timing at full advance that's important but once you know how much advance you have it's a none issue.