Points questions

[rogermansfield]

I replaced the points on my running 1980 RT (with canister). I failed to mark the position of the canister before I removed it. Now I cannot get it to fire. I read Haynes & Clymer and made a "buzz" box. It goes off constantly when the flywheel is at "S". I rotate the canister the full amount allowable and the buzzer does not stop. How can I find a spot where the bike will at least start, then use the strobe to finish the job?

I have replaced them before without any trouble, but can't remember how I did it!

[20774]

If the buzz box won't go off, that means that the points are always closed. Open the gap up some.

[lostboy]

Make sure to set the points gap with the front bearing plate installed. It makes a huge difference.

[sumran]

Make sure to set the points gap with the front bearing plate installed. It makes a huge difference.

I usually set mine before I install the canister, since it provides easy access. Could you explain the bearing plate? I may be doing it the wrong way.

Roger,

Kurt's advice is is the first step and is the likely culprit. I recently had the same non-firing problem. I found out the condenser wire had a break in it and I knocked it loose. I put in a new condenser and it fired up immediately. You can leave the cover off and watch the points open and close. If you are getting reasonable gap on the points on the peak of the lobe and they are making contact at the low point of the lobe, I would carefully check the the condenser and points wire connection. It is also fairly easy to miss the slot in the cam nose with the ridge on the drive shaft of the canister. If you do that the canister gets loose when they align.

[lostboy]

The front bearing plate is exposed when the sheet metal cover is removed from the front of the cannister. It has a bronze bushing to support the points cam.

[sumran]

The front bearing plate is exposed when the sheet metal cover is removed from the front of the cannister. It has a bronze bushing to support the points cam.

Aha. Load bearing as opposed to ball bearing. Thanks. If I am setting the points with the canister on the bike that plate is in place (and in the way :banghead). If I have the canister off the bike I have set the points with that plate removed and then installed the cannister and set the timing.

The cam seems stable with the plate out (at least for hand positioning) but I should go back and check it. Since the setting is in thousandths, it wouldn't take a lot of movement to throw it off.

[Brettendress]

On my airhead I took the plugs out and laid on the ground and rolled the back tire with my foot while looking at the points until the points opened the whole way then loosened the screw so the points closed then gapped them and it started right up and ran perfect. I had the exact same problem and this is how I found top dead center. Hope it helps

Brett Endress
Altoona Pa

[rogermansfield]

Thanks everyone- She's Alive! I apparenly was having a really bad time setting the gap with the canister on the bike. I had installed them with the "canister off", but didn't know how to set them. For anyone new to this, you have to make sure and mark the location of the canister prior to removal. Then install the points set and check the gap first by turning the "lugged gear" on the back of the set. Double checking the gap after install is difficult. You need a "narrow width" feeler guage to work around the front bearing plate and the condenser wire. Do that while laying on the ground with the front tire in the way when it's hot outside and you're tired just to make it interesting.

[racegun]

this might help

http://w6rec.com/duane/bmw/points/index.htm

[rogermansfield]

Went for a little ride tonight and adjusted timing a little. It's difficult to see the timing marks with the strobe even though I put white paint on them when I replaced the clutch. Thanks for the info again. Hopefully, I'll be able to make it run perfectly with a little more time!