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Timing is everything

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GuzziPaul View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GuzziPaul Quote  Post ReplyReply Direct Link To This Post Posted: 08 Aug 2019 at 11:01
I'll be going for a Sachs unit when I have a spare £300, but as it's running ok with points (admittedly high fuel consumption though) I'll leave it for now.
I'll be interested to see how you get on.
You mentioned you couldn't find any useful marks apart for those for TDC. On my bike, it has a lightend flywheel with no obvious marks. Using a degree wheel I was able to find TDC for each cylinder. From there I was able to identify the marks the previous owner had stamped on the starter ring. (1 or 2 dots) depending in the side. Then counting the number of teeth on flywheel, 3.75 degrees/tooth I was able to find the other marks stamped a bit more obscurely for the ignition timing.
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TheWrongTrousers View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheWrongTrousers Quote  Post ReplyReply Direct Link To This Post Posted: 08 Aug 2019 at 11:11
Thanks to everyone who has offered advice to me on this problem. I am quite sure that with your help and given sufficient time I would probably get to the bottom of the problem as i always do. However ....very heavy sigh ... this bereavement has left me feeling like i have been kicked by a horse and it seems as if my usual determination and enjoyment of a challenge has temporarily deserted me. I am knee deep in funeral arrangements and paperwork. I really want to ride this bike and to get out and feel the wind in whats left of my hair while there are still some summer months left to do so. The easier option was to just give up. I will keep you posted as to how this fancy new ignition works out. Lets see if i can avoid buggering this up as well !
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Mike H View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 08 Aug 2019 at 20:14
I sympathise. Ouch


"Chicken nuggets don't dance on a Tuesday."
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Chris A View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Chris A Quote  Post ReplyReply Direct Link To This Post Posted: 08 Aug 2019 at 20:52
So sorry to hear this mate....take things one by one.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Paulsb Quote  Post ReplyReply Direct Link To This Post Posted: 08 Aug 2019 at 22:28
Condolences. And i sympathise with you. I am just about finished restoring an S3 after almost 2 years. Many times I’ve wanted to set fire to it. Every time I thought i was close, something went wrong. The brakes almost broke me. The timing has been a right old PITA. Easy once you figure it out!

First time i started it, it was running one cyclinder. I went through everything, read every useful article on this forum. In the end it turned out to be a loose connection on the points spring. I had replaced the red and green wires to the coils and the spring popped out and i hadn’t realise (doh!) so the problem was intermittent as it pressed against the wires. I finally found that problem after having spent days of going over everything but then the bike was rough during a test run. Took the dizzy cover off and fireworks inside. One of new condensers packed up. Finally going now and will test ride properly next week when i have time. Best thing is walk away and go back another day. I did static timing but timing gun is so useful especially as you need to check advance. guzziology recommends this as the best way to do timing. 

I see you are in South London, I’m in West London just off the end of the M4. If you need any help, PM me. I’m not a mechanic but the every MG i’ve had has turned me into one.

Good luck!


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TheWrongTrousers View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheWrongTrousers Quote  Post ReplyReply Direct Link To This Post Posted: 11 Aug 2019 at 09:07
Well, I believe that I have successfully fitted this Sachs electronic ignition. The bike fires up right away and behaved very well just bumbling down on a trip to the shops and back. It clearly needs to be fitted at exactly top dead centre so I did invest a little time and effort in finally figuring out what some folks here were going on about when they mentioned using a degree wheel rather than relying on the D and S marks on the flywheel. I found this really useful video that made sense of it for me. Easy really, and like others have said, sure enough the exact TDC point was a little way off the D mark. I even made myself a piston stop tool out of an old spark plug and a bolt. I am planning a long ride to the Kent coast next week so i will let you know how it all goes. Thanks again to all who have offered their help and condolences these past few days.

Here is that video for the benefit of those who may not be au fait with using a degree wheel. 



Edited by TheWrongTrousers - 11 Aug 2019 at 11:33
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Chris950s View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Chris950s Quote  Post ReplyReply Direct Link To This Post Posted: 11 Aug 2019 at 11:20
Fingers crossed but it sounds like a good result, well done! Smile
Chris and Karen - Essex
2011 Stelvio NTX, 1974 950S (750S replica nearly rebuilt!), 1966 Triumph T100SS 58 years young this year!
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Mike H View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 11 Aug 2019 at 15:13
Excellent Thumbs Up
"Chicken nuggets don't dance on a Tuesday."
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TheWrongTrousers View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheWrongTrousers Quote  Post ReplyReply Direct Link To This Post Posted: 16 Aug 2019 at 21:20
Well that turned out alright. Fitted my new fancy Sachs electronic ignition having discovered perfect true top dead centre. Bike fired up on the button sounding exceptionally keen. Waited for the rain to abate and off i went on Thursday morning on a visit to see one of my daughters on the Kent coast. From the first moment it felt exactly right and once i got free of the South Circular and on to the M2 this bike grew wings and flew down to the sea. You know how they feel when things are just right ? Well that is how it was all the way there and back. I filled up with the same fuel that led to all the pinking on my last trip, and even though I really tried to provoke it by giving it a massive handful at low speed in top gear all i heard was tuneful exhaust note and huge healthy induction roar as the speedo shot up to ludicrous speeds.  The thing with this Sachs ignition is that it has no less than 9 ( count em !) different pre set advance curves and you can switch from one to another by inserting a small screw driver and turning the dial. So my next experiment will be to fill up on some crappy fuel and if it pinks I can gradually retard the ignition until it stops. That's the theory anyway. 

I also reckon it used comparatively little petrol. I had to back off the throttle a lot of the time just to keep within vaguely legal speeds.  We will see about that after a few tank fulls when I can do some sums. 

The only cloud in the sky was my right hand rear indicator falling off on the way. How on earth did that happen i ask myself ?!  Answer : Thats life, I suppose. 


Edited by TheWrongTrousers - 17 Aug 2019 at 11:35
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iansoady View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote iansoady Quote  Post ReplyReply Direct Link To This Post Posted: 17 Aug 2019 at 11:15
Great news and hopefully now things are on an upward path.
Ian
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Mike H View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 17 Aug 2019 at 18:20
Fab.

"Chicken nuggets don't dance on a Tuesday."
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