Motoscrubs.com

Had a little oil weep from the contactor drive shaft, so replaced the oil seal. On resetting the ignition timing, I noticed the points gap had altered after adjusting the carrier plate. On investigation I found the plate was not a good fit in the timing cover. Checked another plate and two more covers, all were the same dimensions giving about 0.005" clearance.
After some thought, this was my solution to resolve the problem. The plate is now a snug fit in the cover, located on the three datum points, the points gap now remaining constant after timing adjustments.


Mandrel in press to push out indents

Indents

On mandrel in lathe for machining

Datums 0.0025" up on plate o/d

That's a very nice bit of work Brian.

Shame the harmonics of my 450 rendered the AAU useless and I went over to CDI. I have to admit that so far the starting and general running of the engine has been greatly improved by the switch to CDI.

Hope your engine now runs much better.

Good health, Bill

Thanks Bill, one cannot deny CDI is the answer. I suppose I'm living in the past, but on the other hand, points ignition and magnetos for that matter are things I can understand, and hopefully repair if required. It was running OK prior to the oil leak, but things must be operating OK after the repair, as it did take the rev counter round to 7800 in third on the test ride yesterday.

Bit of a hooley then Brian!

Good health, Bill

DBDBrian wrote:Thanks Bill, one cannot deny CDI is the answer. I suppose I'm living in the past, but on the other hand, points ignition and magnetos for that matter are things I can understand, and hopefully repair if required.

Sure enough, CDI makes for easier starts.
The ability to run with points is a great advantage though, for when (not if?) the electronics give up the ghost.

Well, I suppose we all rely on electronics in our modern vehicles, and in general they tend too give very little trouble for the miles covered. But having spent a lifetime in engineering I must admit my knowledge as to their modus operandi is very limited.
Awhile back, the magneto on my Goldstar, which I had rebuilt many years ago failed. So I thought I would go down the electronic route. I built up another mag , dispensing with the armature, and making a new shaft to carry all the bought in electronic gubbins, also retaining the manual advance / retard setup.
It produced a big fat spark at kickstart speed, and performed well, but it was TOTALLY unreliable. It now resides in a cardboard box.
I rebuilt and refitted the original mag. This is probably tempting fate, but to date it's performing OK.
So on reflection I think I will be sticking with things of which I have some understanding in the event of their malfunction.

Aye Jordan, that's a circular argument that I have been round since purchasing the 450 in 1976 and have gone full circle.

If only '70's electrickery components had been more robust and after 45+ years corrosion and degredation take their toll on any still surviving. I have still kept the mechanical components "Just in case!"

Good health, Bill

I have Lucas rita ignition on the 350mk3 and points on the 250 desmo, if the Lucas system fails I will have to replace it with points again (and I sincerely hope it does'nt go 'phut' at the side of the road 60 miles from home), if the points fail I will fix it at the side of the road with the spare points and condenser stashed in the toolbox
Cheers,
George