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[Daiwiskers]

A spot of weld on the backing plate would be easier than trying to weld the slots and would only effect max advance

[Vince2]

Hi, if you look at the backplate from behind I think you'll find that the movement is limited by a peg which passes through it from the advance weights. Just a a blob of weld and file to adjust. Vince

[Meteorstorm]

I went through all this 15 years ago,from memory it's best to use JB weld on the backplate slot as previous 2 posters note,and build up the idle advance side first as that will load up the springs a bit,H sell stronger springs too.I ended up taking a little off the weights too,but really why don't you just get a programmable electronic unit? They were out back then.With the points on the 612 you will have to baby it in certain situations like under load up a rise,so i would go electronic if i was to go through all that again.

[stinkwheel]

I'm not sure there is a programmable electronic ignition out there? I thought I'd done the right thing with the crank mounted electronic one but as I say, it seems pretty glitchy. I've found a new advance unit on ebay so I'll see how that measures up and I then have a few spares kicking about for fiddling with. Also ordered some stronger springs and another compression plate for if I just need to detune it a bit.

Considering doing a proper drawing for a degree wheel that can be laser cut/etched from stainless or aluminium and bolted to the stator mounting studs on a lucas style stator to make use of the markings on the rotor. Then the standard stator nuts could be replaced with sleeve nuts so the degree wheel can be bolted on. Way more accurate than messing with one of those measuring things that goes in the plug hole or trying to get a pointer in place and bolting a disc down to the rotor without it moving. My ersatz cardboard effort made the job really simple and gave good dynamic timing points. If I go down that route, I'll get them to do several. I'm surprised one doesn't already exist considering these alternators have been out for over 40 years.

[Wheaters]

I bought an “Aldon Amethyst “ ignition unit for my Reliant engine when I finally became tired of continually removing, dismantling and modifying my Lucas distributor.

It’s quite expensive, but it works very well. You have to lock up the mechanical advance to make it inoperative then you programme in the ignition curve you want using software on a laptop. You can even change the settings with the engine running. It works with points, or with an electronic trigger. The box even has a red LED which works as a timing light. It also has a switch to allow two curves to be used, or the switch works as a cut out for anti theft use.

The box is a bit big for a bike, but it could be made to fit in a tool box.

Personally, I’d just modify your advance bobweights as I already suggested, minimal effort and cost!

[stinkwheel]

Had a brain-wave with regard to restricting range on the mechanical advance. I could drill and tap a small hole on the face of the bob-weight and fold up a small hardened U-shaped shim that fits over one end of the slot (think disc brake anti-rattle clip) and is held down in place with a small threadlocked screw or even a small pop-rivet. This would allow for adjustment by varying the thickness of the shim.

Might not need to do it at all if the new advance unit is in the right ball park, then it's just messing with springs and weights.

I do know the original Hitchcocks one was electronic and they put it back to points due issues getting reliable starting without kick-backs.

[Daiwiskers]

Be caerfull with eBay advance units !
They can break up leading to a long wait on the side of the road for recovery and some considerable time working out what the problem is

Wonder how I know that Dai

Edit just bite the bullet and buy one from our hosts or be prepared to weld up the cheaper one when it fails

[stinkwheel]

Hitchcocks are out of stock, there are precious few on ebay too, even from India.

I think it's a proper bagged RE one I've got, it's from a small UK seller selling an assortment of RE parts as if they've had a few spares and have got rid of the bike they go with. But yes, I'll be checking it's up to scratch before fitting. Particularly with regard to the hardness of the cam and pins.

[stinkwheel]

As an aside, I'm now actively looking into getting something like this made up from stainless or alloy. It could probably be left permamantly attached once it's dialled in (pending prototyping to see if there's enough space under the primary cover) and would take all the guesswork and fiddling out of the job.

If I go ahead with it, I'll get a few made because once it's set up, making extra ones isn't all that expensive. All very much at the concept stage for now though. I'll need to learn how to make a proper CAD file among other things.

degree wheel.png (129.48 KiB) Viewed 7878 times

[Davedup]

That's looks a great idea