Morris Magneto timing

Matatac

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Ladies and Gents,
Since I live in Vietnam and there is no local dealer to take my XS bobber to for constant repairs (and motorcycle boots are not made for walking long distances in), I decided to go for the magneto setup.

Got the Morris Magneto from the states and am having a little problem timing it.

The unit itself is a work of art but when it came time to mount it, thats where the problems began.

Instructions said to remove the left side cover and mount the drive adaptor to the shaft running through the cam. First problem. I removed the cover to find no shaft running through the cam at all, no points, nothing. It had some aftermarket system fitted (not very well) causing it to run like a pig, thus why I went for the mag.

I spun up adaptors and through shaft on a lathe out of some old forward control shafts and it seems to run ok. I just want to double check the timing now.

As with old points gear, a normal 12v light bulb across the points is ok to static time it but when the Magneto cover is removed, the points actually come loose. The pivot for the points is in the cover. The closest I can get is shine a bright torch throught the cover and try see when the points open.

Next problem is the timing mark. I've read heaps on here about the timing marks for the 79 model but something doesn't quite click.

On the internal rotor, there is a fixed mark. On the removable case, there is a metal tab marked F and T held on by a small screw. What I don't understand is why this metal tab has a slot in it to slide back and forth approx 13mm or 1/2"? Not sure how I can time it if I don't know extactly where this plate is supposed to be?

Main reason to double check the timing is when it runs, it backfires through the carbs so savagly that the foam airfilter pods have blown out! I've checked compression (ok), valve clearance (done), cam tensioner (perfect). Carbs are new from MikesXS. I've set them up to pull at the same time using a 2mm drill bit in each carb to check the slides move together. I want to stick vaccuum guages on it but need to modify the new inlet manifolds to allow for a vaccuum port. Thats next if I can get the timing sorted :banghead:.

Long winded way of saying I'm kinda stuck here. As I said, living in Vietnam makes it difficult to 'duck down the dealership or wreckers' to grab something. This XS is one of 2 in the whole of Vietnam and they are both mine. Had heaps of pictures taken of it when I go out but the backfiring makes me a bit scared (the flame is too close to my nuts!!! :yikes:)

Any help would be greatly appreciated folks!
 
Well how lucky are you to be riding an XS in such a beautiful country!
So, what you need to do is find top dead centre and then mark or adjust your metal tab to align with the mark on the stator. I think that's why it's adjustable?
So two methods to find TDC:
1. Pop a the plugs out and turn the engine over shining a torch into the bore. TDC is when the piston is at the height of its stroke on the compression stroke
2. A little more accurate. Get a degree wheel (print one off on line) bolt it to the crank bolt on the stator and fashion a pointer so you can read the angles. Get an old spark plug and extend it about an inch. Screw said plug back into the head. Turn the engine (gently) until it hits the stop. Note the angle. Turn the engine all the way back round til hits hits again. Note the angle and split the difference. Turn the engine back round til that split angle shows. That is true TDC. Set your plate to that. Incidentally, the T and F stands for TC and Fire. Fire being your advance mark.
Use these marks to set your timing
 
Matatac,

Well, I sold a PAMCO to someone in Vietnam last October, so there must be at least three XS650's in Vietnam, unless that was your other XS?
 
Thanks for the advice guys. I'll give that a try and see what I can come up with. I love the old girl and really want to take her out more often. Riding big bikes is still illegal here (well, big bikes are not, it is just impossible to get a licence for one) so I always have to keep 500,000 Vietnam Dong in my wallet ($25usd) tp pay off the cops if I get caught. Problem is, it runs so bad I can't make a getaway! hahaha. Easier on my dirtbike!

A friend of mine bought a Pamco kit for the one we are still doing up. It would be nice if there were more around.

Thanks again guys.
 
Well, pleased to say she now goes like a scolded cat!
Spun up a longer insert and fitted it into an old spark plug. Did the 'turn forward slowly, mark it, turn backwards, mark it' suggestion to come up with a TDC which I then moved the plate to line up to. Used an old protractor and came up with the correct advance as what was suggested online. Road my scooter 3hrs to the city to get a timing light (don't laugh, I can only piss with the willy I have :D) and rode back. 110cc Honda Waves might be unbreakable, but their seat has a lot to be changed!

Anyway, hit it with the timing light, adjusted it a few times and now it runs the best it ever has!

Thanks heaps for the advice guys!

IMG_068311.jpg
 
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