ignition base plate

[Keith.P]

Wear and tear on the bottom bush would drop the flywheel anyway.
The crank in front of me mic's up shorter.

[Oyster 49]

Could it just be a timing dimple machining a little too low? The engine could have like it since day one!

[Charles uk]

The height of the crankshaft projecting above the top main bearing bush on my OP is 71 mm or 90 mm to the bottom of the crankcase step where the baseplate sits.

There is virtually no end float on the crankshaft on the OJ, ON & OP.

There is no "dimple" so that is not a concern!

[Oyster 49]

Yes, but this is a SD isn't it?

[Charles uk]

Woops got that wrong sorry!
My mistake
Doesn't the SD have a steel inner collar rather than a dimple?
As do all JM ignitions.

[Collector Inspector]

I asked if the taper could be checked in my first reply?

Have you done that check?

When you do, it will have to be on an SD crankshaft. They have a lot of thread almost to the start of the morse. No mistaking them.

There is no locating dimple......................(There may be an indexing centre punch or small 1/8th Locating mark, This is not for the clamp screw to locate in) The clamp screw compresses the split ring insert to lock timing setting.

Timing is done manually back from T.D.C. T.D.C. is key facing through centre case stud.

Yes Charles this is why I questioned the base plate. The casting is different to Seagull JM externally.

There is a sleeve.

Stationary engines were different in most cases.

I think there is a lot of incorrect and/or a deal of part swapping going on. Makes it hard.

You will work it out.

B[/color]

[bikerboyfife]

Hi guys thank,s for the info have decided to come away from it for a week needing to clear ones shed out will get back to it asap thank,s cheers for taken the time and effort getting back to me got wullie nelson on the wireless and a glass of bells bubbly on the bench where that leeds me i dont know thank,s

[headdownarseup]

That's interesting B
I had been of the opinion that most (if not all) the coolie mags had a brass points box.(SEAGULLS not stationary motors)
yours (and mine) have an aluminium points box.I had thought previously that my magneto had been "got at" by the monkeys? or maybe that it had gone back to villiers at some point for "refurbing"
does yours have the lock nut on the points? or the normal single screw adjustment.

jon

[Charles uk]

All the JM (coolie hat) type ignitions were fitted with the brass points boxes during the war, the MOD were not famous for making their spares situation more complicated during times of conflict.

Aluminium point boxes must have been a later repair.

[Collector Inspector]

Interesting so chased up this pic.

Question is why throw away a basically indestructable brass box? The coil is obviously an Australian replacement. Rofo were 1952 - 64 or there abouts.

Would it have had a brass box with nut job points originally but only the lever type was available and did not fit as per nut job?

A few years ago but I had trouble with the point gap. I think that it was really small to get a static timing set?

Something is not correct.

I was thinking at the time that....................the point trailing arm was too long?

B
[/color]

[Keith.P]

As it has had a replacement coil, so it may have needed a new set of points, what would be easier to find, an original set of points or a later replacement set, its more likely to be a previous owner mod than anything else.