CB550 Points - Arrrrggg

[Neilw]

I keep hitting one problem after the next when putting this bike together, and now I've stumbled across another little gem.  If I wasn't already bald, I would be now!

Got to the point of setting the points and timing, one step closer to finding out of the bike will start.

Well, when setting the points gap on 2-3 I noticed that the points were slightly bent, they didn't sit flat on the points plate, making it near impossible to set the gap correctly and then the timing. No worries i thought, i'll just buy a new set from David Silvers and away I go. Of course i've now discovered that the points are too big, so i resolved to take the original apart to see if i could straighten them.
Job done, refitted and set the gap. When setting the timing the points moved as i rotated the engine and looked to have bent again! The cause I've now discovered are the threads in the backing plate have at some point (not by me), been stripped and were only just holding the points in place.

So now i have stripped threads in the 2-3 backing plate and bent points again!

I feel i can sort the backing plate - either by buying a new one or by buying a helicoil set, but what about the points? - do i try and fix the ones i have (the face has some small pitting), or is there anywhere i can get the correctly sized ones for the 2-3 side?

Your collective wisdom is very much appreciated.
Neil.

[McCabe-Thiele (Ted)]

Fitting a helicoil on a relatively thin plate is fraught with difficulty.
I would be minded to find a used replacement.
I bought one from 400spares, it happened to have a decent set of points as well.(All Tec)
Iirc same plate on the 400 & 500

[Bryanj]

Any points plate from a 400/500/550/75] will fit.
Setting the points and timing is the fidliest job on a Honda and when doing it regularly you develope a knack as when you rotate the plate the gap alters and when you alter the gap the timing moves, as you have discovered.
You have to buy a decent set of feelers to get the0.35 you need(14thou).
One thing i have done in the past is if the big plate is extra sloppy in the crankcase poles fit some very thin bent shims to reduce the diameter BUT it has to be an equal shim on each post

[deltarider]

My advice is NOT to time dynamically. The plate will vibrate too much. Set and check by strobe, but kill the engine to make an adjustment. Then check again. You may have to repeat this. This way you don't have to shim.

[Oddjob]

Probably got a second hand points plate for the 500/550 lying around somewhere. Should also have some stainless steel points screws as well. Complete with captive plain and spring washers.

[Neilw]

Probably got a second hand points plate for the 500/550 lying around somewhere. Should also have some stainless steel points screws as well. Complete with captive plain and spring washers.

Thanks, I've just purchased a plate with some spare nos points, so hopefully that will fix the issues.

[Oddjob]

Are the points TEC or Daichi? Daichi have a 3 bladed propeller on them.

[Neilw]

Are the points TEC or Daichi? Daichi have a 3 bladed propeller on them.

They are F.E.W. (Futaba Electric Works).

[Oddjob]

Not very well known but supposedly ok.

[Neilw]

The new backplate with points arrived and is all fitted. I reused the existing points as they cleaned up nicely - I may replace them at a later date, once I get this thing going.

I have two issues now with the timing - I've managed to get the points gap set ok.

Firstly, on the 1-4,  the backplate is at its limit for turning. I can get the test light to light at T but can't rotate the plate anymore to get my test light to light on the F.

Second issue is i don't get the test light coming on at all when trying 2-3; I've left the light in place for a couple of full revolutions and nothing. I went back and opened up the point gap a hair to see if that helped, but same results.

Any ideas for each of these issues?  The battery is strong and I've been careful switching the ignition/run on while testing, but something is obviously wrong, and i don't know where to start.

[Neilw]

The new backplate with points arrived and is all fitted. I reused the existing points as they cleaned up nicely - I may replace them at a later date, once I get this thing going.

I have two issues now with the timing - I've managed to get the points gap set ok.

Firstly, on the 1-4,  the backplate is at its limit for turning. I can get the test light to light at T but can't rotate the plate anymore to get my test light to light on the F.

Second issue is i don't get the test light coming on at all when trying 2-3; I've left the light in place for a couple of full revolutions and nothing. I went back and opened up the point gap a hair to see if that helped, but same results.

Any ideas for each of these issues?  The battery is strong and I've been careful switching the ignition/run on while testing, but something is obviously wrong, and i don't know where to start.

I'm having a bit of a chat with Chatgbt and going through some diagnostics, i'll let you know how i get on - for the 2-3 issue i suspect a short.

Issue 2 is sorted, it was a short caused by the way i'd put the wires on the points.

I'll have a look at issue 1 tomorrow.

[Oddjob]

Not sure how you are attempting to time the engine up. Do 1-4 first, find the part of the timing ng cycle where the points gap is biggest, now adjust the points so they are opening around 12-13 thou. Lock the points at that setting. Now turn the whole plate so they are opening light comes on at the F mark, lock the plate. No do the same with 2-3, gap around 12-13 thou. Then move the backplate those points are mounted on to get them to open on the F mark. That should be it. With no standard points you need to go smaller on the gap to get 2-3 to time up.

[TrickyMicky]

For what it's worth, a few years ago I decided to take the wise decision(sic) to save money and buy a  new pattern fully assemnled backplate. There was noy waynthat I could get spot - on timing for both sets of points, so it became a compromise between 1/4 & 2/3.  First time out and one of the condensors failed 50 miles from home. Returned back home in the cab of an RAC truck.  Dug down my box of bits, found the original backplate and fitted 2 sets of genuine points. This I am still using which means the condensers are now 50 ears old.

[Bryanj]

Being honest, i never changed out original Honda condensers in all the years i worked at dealers and points were cleaned and reused over 75% of the time, judicious use of a thin diamond file works wonders.
Similarly rarely used a stobe just a static timing light.
Of course this was on fairly new current models not 50 year old abused examples

[Oddjob]

I never changed the condensers either. Points yes, they were cheap back then, especially if you got trade discount. I must have kept quite a few of them as I found quite a few sets of points in my Snap On toolbox the other week. Still usable as well with a bit of work and a decent file.