400/4 Ignition question

[Beemer634]

Help required again please guys.....I have decided to remove the electronic ignition fitted to my 400/4 and fit it to my 550/4 as I will be selling the 400 before long. Can anyone tell me if the points cam is the same on these 2 machines? I have a points assembly on a backplate but dont have a cam for the 400.
Hope this makes sense,   Thanks.
Rick

[Yoshi823]

I'm sure that there's a number on the auto advance/retard back plate that signifies which one goes with which model. I seem to remember someone wanting to buy a new backplate/advance/retard unit once & it wouldn't work properly for some reason...whether it was the weight of the counterweights or the total lift of the cam i'm not sure.

[Beemer634]

Thanks for that Yoshi, I managed to get both bikes apart today and there is a difference in the size of the cam. I am now looking for an advance/retard unit just to get the points cam, just my luck, none on ebay at the moment!!
Rick

[matthewmosse]

If you can tell me how to spot the difference between a 500/550 points assembly and a 400/4 one I know I have a 400/4 one mixed in with all the 500 and 550 bits and it would help me to get rid of an inposterin my spares.

[Bryanj]

the 500/550 has 323 on the back, with luck the 400 has 333

[matthewmosse]

Thanks Brian,
I'll look for it over next few days.

[Bryanj]

Beemer there is a man on the US site who has been running a 550 with a 350 auto advance so i pointed him towards your wanted ad

[Yoshi823]

A word of warning about the points cam...it can go in place two ways. You'll soon know if it's in the wrong place as the bike won't start.