Forum

[windmill john]

I’m doing a little work to Gupta and will be checking timing.
I’ve got the Hitchcock article and I have the Boyer red ignition box.

I’ve got a timing disk and although I’ve timed many bikes, I’ve never used a disk! Mostly Japanese and German bikes that I’ve statically timed and occasionally strobed; never had a bike without marks.

I’ve read the article and will mark as per. Just wondered two things. Anything to watch for? And out of interest, if I mark the stator at 32 degrees and TDC, I guess there’s no way of triggering it manually and watching for spark at plug? Well you could, but it wouldn’t help as you wouldn’t know exactly where it should spark statically; might not be exactly TDC.... but it could be.... in other words, is static at TDC?

Oh, is the nut normal, or a left hand thread? Thanks

[jawa-enfield]

The nut is normal, i do not have experience with this type of ignition, but you can rotate the crankshaft and see if the plug sparks at the right moment?

[windmill john]

Yes, that’s what I was thinking, just see if spark happens at TDC. I just wasn’t sure if it occurs exactly at TDC.

[jawa-enfield]

Good question, the 32 degrees is fully advanced, but what should be the moment when testing/idling?
Isn't there a instruction how to set up this ignition?

[stinkwheel]

Looking at the article in question, they say the fully advanced timing point should be 32 degrees BDTC and that a boyer has a 30 degree advance curve. Therefore you'd presumably set static timing at 2 degrees BTDC.

This is odd because a points ignition static timing should be set at 10 degrees BTDC (presumably the mechanical auto-advance has a 22 degree arc of operation).

You can immediately see why an electronic ignition might make them start more easily.

The thing is, the pickup on an electronic ignition is a hall effect sensor so it'll only trigger with a moving piece of metal. I can't think of a way to do static timing other than by very roughly pointing the lobe of the trigger at the middle of the sensor. There is also the consideration of the enormous amount of backlash on the timing gears. So dynamic timing it is then...

I can see nothing stopping you scribing/teeping a T and F mark at TDC and 32 degree BTDC on the rotor once you've found where that is (or mark TDC and use a protractor?). They are keyed onto the crank after all, but what's the reference point to observe them from? Maybe you could fold up a little alloy plate with a "window" in that bolts onto the stator studs? Or drill and tap a peep-hole in the primary drive cover like they have on Japanese bikes?

I've got an electrex system which is really simple. It's crank mounted and once you've found TDC, you set the position of the rotor, lock that down then use a ruler scale on the rotor to set the advance by adjusting the stator position. It's not without its own difficulties though. Not least of which is a super weedy lighting output. The other of which is the rotor is NOT keyed, just tapered onto a collet. It's possible it could slip/spin up.

[windmill john]

Good write up Stinkwheel. Your point about movement makes sense about not being able to time statically.
No worries, I’ll mark the stator and time ‘properly’.

I wonder...... if there is any pressure in the timing case. If not, then I could drill and fit a bung ala BM and Guzzi. As the Ali is thin there, tapping would involve building up the ali; out of my league.

But if there no pressure..... a bung would work.... or just forget drilling and set timing and forget... it is electronic so shouldn’t shift for a while...

[stinkwheel]

There is no pressure, or there shouldn't be. If you look closely, there is a small hole in the middle of the filler nut, presumably to allow it to breathe.

[windmill john]

Thanks again. I’ve got loads of bungs; well rubber blanking plugs. I’ll time it up and mull it over.
I’d be interested to know if anyone has done this.

[stinkwheel]

I'd just set it and carry on if I were you. I'd even be tempted to threadlock the adjuster nuts. Good to exercise the brain though.

[jawa-enfield]

There should be a youtube how-to if the instructions are hard to do/interpret?

Maybe many people stick with the point because of insecurity about being able to nstall such an electric ignition system.

On my '67 jawa i installed a Velleman-kit. It keps the points and it works very well.
I thought about doing the same with the petrol enfield but.. the -pissibly troublesome- advance system also would stay this way and THIS is a main advantage of other electronic ignition systems?