No Spark

[Saesneg Shaun]

Wondering if the rod is backing out of the crank which will release the advance mech ?

If that's happening, then the securing nut may be reaching thread end before tightening mech properly.

The rod seems to be in rock solid. What is very worn is the large nut with the slot in the middle. Years of cranking the engine over on it has turned the centre oval. I don't know if you can just buy the nut?

Actually just looking at the cost of the advance unit/points/condensors on DSS I might as well do an electronic conversion!

Any recommendations? DSS unit or Boyer seem reasonable choices.

[K2-K6]

Likely you'd get someone with a nut on here to help you out if you put request out for one.

Electronic, many use the advance mech to then run various levels of electronic switching.

Boyer is fully electronic, triggering, advance the lot and has very good reputation for performance and reliability also. Probably the most proficient if you're changing.

Unsure if Boyer needs that nut too, or has alternative. 

[Oddjob]

Sure I've got one somewhere, just need to find it.

CMS have them at 18 euros or so. DS don't stock them.

[Saesneg Shaun]

Thanks for the help guys.

I'm totally fed up with messing about with the points so have ordered a Boyer Electronic Ignition kit.
I went for that one as it doesn't use the stock advance unit compared to the DSS unit and they have been around for donkies years.

[Saesneg Shaun]

Just to update this I fitted the boyer electronic ignition today and she's running on all four again.

Its looks like my problem was the large nut had been used to crank the engine over and had gone oval in the middle. Even with the 10mm nut done up the big nut was still moving around. Fortunately the Boyer kit does away with the large nut and the points cam.

I have a bit of popping through the exhaust but i'm waiting for a strobe to be delivered then I can time it properly.

[K2-K6]

Good you've got to the bottom of it.

Those are timed at full advance as you can't set them like a mechanical system that advances the trigger point. They effectively run at full advance with a rpm register internal that allows them to retard only from set point for start and low rpm.

Seems a bit odd if used to conventional mechanical system, but logical once you think it through. 

Should be easier to start now 

[PHILIP2908]

I've got the same problem; the spindle and nut scribes an oval as the crank is spinning. You can set the timing OK but it plays havoc with the points gap.
As you say its caused by monkeys turning over the engine with the plugs still in: the compression proves too much at tdc and the spindle bends.
I had a look at a replacement but none seem to be available. From the parts diagram it looks as it just screws into the end of the crank.
I also thought about removing it and getting it straightened by an engineering shop but then had nightmares about it snapping off on removal which would probably necessitate a full strip down to get at the crank.
Consequently I will probably go for the Boyer system too. Can you please give some feedback on ease of fitment and what effect it has on the running?
Best regards
Phil

[Bryanj]

The 750 spindle is available as a spare and has an O ring on it where it screws in

[Lobo]

I removed my spindle recently - not easy. Heat, molegrips, rattle gun (on low) all to no avail. What worked in the end was a roller cam stud extractor, obviously down near the base. But still nail biting…

[Saesneg Shaun]

Well dang, its still not sorted.
Got the ignition timed with a strobe lamp to full advance at 4500rpm.
Also did a carb balance whilst I had the bike partly disasembled (I know, I know, should have tackled one issue at a time)

Road tested today and she won't accelerate over 4000rpm in any gear. Tried with the fuel tap on and in res and with the cap open but with the same result.
Starts and ticks over fine.

Any ideas?

*edit, just pulled the plugs, No's 1,3&4 very black and sooty, No 2 tan/clean?

[Saesneg Shaun]

Found the cause.
I just popped the float bowls off to find 1,3 & 4 main jets in the bottom of them 
I didn't tighten them up and they rattled loose. No wonder the plugs were were black lol.

[K2-K6]

     oops!

At least you found them quickly.