Installing a Sparx 3-phase alternator. I need some help!

Note that when you go to fit your Sparx rotor its bore is undersize to allow it to fit worn crank mainshafts, if yours is not worn then the bore will need opening up.


I did not know that



niether did I. Mine fitted straight on with no mods to the rotor bore. ????


the nut is a regular thread Coco

millard

Coco said:

It's still strange why it wouldn't shift up simply using the gera lever without turning the wheel. Explanation?

Click to expand...

This is a very common question and as practically all motorcycle gearboxes work on roughly the same principal it is a little surprising (to me at least) that it gets asked as much as it does..however, the gears in a motorcycle gearbox need to slide sideways into engagement with the gear next to it in order to lock it to the shaft, as some gears are splined to the shafts and others are free to rotate, so each of the engaging dogs (like wide pins) on the side of one gear need to drop into a corresponding space in the gear next to it (the actual gear selection sequence is a little complicated to explain so see the link below). If the dogs on each pair hit head on then the selected gear will not engage until the gear rotates enough so that the dogs drop into the spaces.
This is what happens when the gearbox is operating normally, so generally this needs to be done when the gearbox shafts and gears are not being rotated by the engine.

http://www.oldbritts.com/gearbox_info.html

Whether you can select some or all gears with no shaft rotation is a matter of luck where the shafts/gears are positioned each time.

I'm sure the rotor nut is normal right-hand thread.

It may be possible to cut a piece of wood to a size that fits tightly diagonally between both tooth sets on the primary sprockets although a bit awkward on MkIII (even with the tensioner/starter drive mechanism removed) to act as an extra locking device.

L.A.B. said:

Coco said:

It's still strange why it wouldn't shift up simply using the gera lever without turning the wheel. Explanation?

Click to expand...

This is a very common question and as practically all motorcycle gearboxes work on roughly the same principal it is a little surprising (to me at least) that it gets asked as much as it does..however, the gears in a motorcycle gearbox need to slide sideways into engagement with the gear next to it in order to lock it to the shaft, as some gears are splined to the shafts and others are free to rotate, so each of the engaging dogs (like wide pins) on the side of one gear need to drop into a corresponding space in the gear next to it (the actual gear selection sequence is a little complicated to explain so see the link below). If the dogs on each pair hit head on then the selected gear will not engage until the gear rotates enough so that the dogs drop into the spaces.
This is what happens when the gearbox is operating normally, so generally this needs to be done when the gearbox shafts and gears are not being rotated by the engine.

http://www.oldbritts.com/gearbox_info.html

Whether you can select some or all gears with no shaft rotation is a matter of luck where the shafts/gears are positioned each time.

I'm sure the rotor nut is normal right-hand thread.

It may be possible to cut a piece of wood to a size that fits tightly diagonally between both tooth sets on the primary sprockets although a bit awkward on MkIII (even with the tensioner/starter drive mechanism removed) to act as an extra locking device.

Click to expand...

Thanks LAB. I'll try the wood block if choking the wheel is not effective. I'm going to have another go at this mess all day Saturday and Sunday.

Re: gear selection. I recall being able to shift through all the gears effortlessly with the bike on it's centre stand a few days ago before I took the primary cover off. That is why I was a bit stumped when the bike would not shift into 4th without me turning the back wheel.

LAB, some good info here. Thanks!

My trick to remove the rotor nut is to use an old plastic handle from a screw driver inserted snugly at the inside of the lower run of the primary chain and butting up against the teeth of the clutch basket. A quick zip with an air driven impact will loosen the nut easily.

Installation is the reverse, with the screwdriver handle at the top run of the chain and a torque wrench on the rotor nut.

The screwdriver handle I use has many scars from this process, but I am confident it will sacrifice itself before the chain or clutch basket teeth.

YMMV

Ron L said:

My trick to remove the rotor nut is to use an old plastic handle from a screw driver inserted snugly at the inside of the lower run of the primary chain and butting up against the teeth of the clutch basket. A quick zip with an air driven impact will loosen the nut easily.

Installation is the reverse, with the screwdriver handle at the top run of the chain and a torque wrench on the rotor nut.

The screwdriver handle I use has many scars from this process, but I am confident it will sacrifice itself before the chain or clutch basket teeth.

YMMV

Click to expand...

Nice. Good tip as well. I'll try the screw driver handle and wood block approach on Saturday. I'll make sure to report back with success or failure. Hopefully it will be the former. Thanks everyone.

Ron L said:

My trick to remove the rotor nut is to use an old plastic handle from a screw driver inserted snugly at the inside of the lower run of the primary chain and butting up against the teeth of the clutch basket. A quick zip with an air driven impact will loosen the nut easily.

Click to expand...

I have used a scrap piece of wood instead of a screwdriver handle.

Update:

I didn't get to the rotor nut (removal of old alternator/install of new 3-phase rotor) this past weekend as expected, but I did start ripping out the old coils ect.

Holy wiring Batman!

Question. I know I am getting rid of a lot of "stuff" by going with a Sparx system, so off went the Zener diodes, blue capacitor, and old coils as I've switched to a dual fire, single coil. There is a little, rubber covered, rectangular box (says LUCAS on it) with two spade conenctors that lived under the "U" shaped, coil mounting bracket. I removed that rectangular box as I assumed I wouldn't need it. Anyone know what that is/was for? The bike does have a Boyer electronic ignition that is being replaced with the Sparx kit.

Coco said:

There is a little, rubber covered, rectangular box (says LUCAS on it) with two spade conenctors that lived under the "U" shaped, coil mounting bracket. I removed that rectangular box as I assumed I wouldn't need it. Anyone know what that is/was for? The bike does have a Boyer electronic ignition that is being replaced with the Sparx kit.

Click to expand...

That is the ignition condenser pack for the original points system, as you have a Boyer (or Sparx later on) ignition fitted it isn't needed.

L.A.B. said:

Coco said:

There is a little, rubber covered, rectangular box (says LUCAS on it) with two spade conenctors that lived under the "U" shaped, coil mounting bracket. I removed that rectangular box as I assumed I wouldn't need it. Anyone know what that is/was for? The bike does have a Boyer electronic ignition that is being replaced with the Sparx kit.

Click to expand...

That is the ignition condenser pack for the original points system, as you have a Boyer (or Sparx later on) ignition fitted it isn't needed.

Click to expand...

Thanks LAB. I also removed a white ceramic piece (riveted onto a small metal bracket) with 2 blade connectors on it as well. I assume that is now irrelevant as well.

Coco said:

Thanks LAB. I also removed a white ceramic piece (riveted onto a small metal bracket) with 2 blade connectors on it as well. I assume that is now irrelevant as well.

Click to expand...

Yes, no longer needed, that is the ballast resistor.
---------------
Addition

...along with any white/purple (ballast bypass) wires you may find, from the starter solenoid to the coils.

The trick is to use impact, if you can get a wrench or spanner on the nut, apply pressure & sharp blows with a hammer to the spanner & tru to shock it free, this is kinder to the parts than long extension bars & loads of force. Try heat as well as this can free things off a bit loctite or not.

L.A.B. said:

Coco said:

Thanks LAB. I also removed a white ceramic piece (riveted onto a small metal bracket) with 2 blade connectors on it as well. I assume that is now irrelevant as well.

Click to expand...

Yes, no longer needed, that is the ballast resistor.
---------------
Addition

...along with any white/purple (ballast bypass) wires you may find, from the starter solenoid to the coils.

Click to expand...

Thanks.

I'm glad I was removing all the right pieces. I got a little carried away actually. I went in to remove that stubborn rotor no=ut and got totally sidetracked ripping out the guts of the old electronic ignition and left overs from the original ignition as well.

Too many wires now! :shock:

I need to seriously wrap my head around the electrical now as well as removing that damn nut.

Thanks everyone.

Coco, if you don't have an impact wrench then do what I did a coupla years back before I got my compressor. Get the bike on a trailer or in a van and take it to a tyre fitter. Take the correct socket with you and get them to spin the nut off with their impact wrench. It'll only take them seconds.
millard

millard said:

Coco, if you don't have an impact wrench then do what I did a coupla years back before I got my compressor. Get the bike on a trailer or in a van and take it to a tyre fitter. Take the correct socket with you and get them to spin the nut off with their impact wrench. It'll only take them seconds.
millard

Click to expand...

Actually I am working on the bike at work in our shop and I have a full complement of air driven tools here.

I got the rotor nut off no problem when using an inpact wrench. Yay!!!

Trying to wire in the 3-phase rotor and Sparx ignition has turned into a total nightmare. Booo!

Whomever wired in the previous Boyer electronic ignition should be shot. I don't know much about motorcycles, but I know good wiring and mechanicical work when I see it and this bike has neither.

Although I'm the third owner, there are things that seem like it's been passed around and had some shoddy work done.

I have bills for all work done, down to spark plug changes but there is a lot of stripped bolts, hack and slash repair work and just some weird wiring.

The sun is shining and my bike is in pieces. I'm totally lost now and think I'm in over my head.

I might cave in and pay someone to finish wiring in the ignition, if I could only find someone locally who I can trust who has worked on Nortons.

I am getting totally demoralized with this whole thing.

Coco said:

Whomever wired in the rpevious Boyer electronic ignition should be shot. I don't know much about motorcycles. but I know good wiring and mechanicical work when Is ee it and this bike has neither.

Although I'm the third owner, there are things thats eem like it's been passed around and had some shoddy work done.

I have bills for all work done, down to spark plug changes but there is a lot of stripped bolts, hack and slash repair work and just some weird wiring.

Click to expand...

Welcome to the exciting world of vintage British motorcycles! If it makes you feel any better, you have plenty of company. All of these things are par for the course...

Debby

I think I'm just going to pay a local restorer $60 an hour to finish everything off wiring wise. I want to ride my Commando and not look at it sitting in my shop in pieces.

I thought the alternator/ignition upgrade would be a simple connect the dots procedure but Iwas sadly mistaken. I feel like I've been beaten and I usually don't like to give up but while all my friends are riding around (on CB 750's mind you) I am getting pissed off and annoyed.

This is my first venture into motorcycle repair, but I am unhappy that I've been so discouraged this early on.

Coco said:

Whomever wired in the rpevious Boyer electronic ignition should be shot. I don't know much about motorcycles. but I know good wiring and mechanicical work when Is ee it and this bike has neither.

Click to expand...

Sorry to hear that. It's not surprising Boyer ignitions get such a bad press considering how many of them must be wired up the same as yours.

Coco said:

I have bills for all work done, down to spark plug changes but there is a lot of stripped bolts, hack and slash repair work and just some weird wiring.

Click to expand...

Yes in many cases bills for work/parts are no guarantee that things have been done correctly -unfortunately. That's why we like to do these things ourselves, as there is a certain satisfaction in getting it right, and nobody but ourselves to blame if we get it wrong.

Coco said:

The sun is shining and my bike is in pieces. I'm totally lost now and think I'm in over my head.

Click to expand...

You have this forum so you're not alone.

Coco said:

I might cave in and pay someone to finish wiring in the ignition, if I could only find someone locally who I can trust who has worked on Nortons.
I am getting totally demoralized with this whole thing.

Click to expand...

I'm sure most of us here have felt the same as you do at some time?

Isn't there anybody you know who lives nearby that could give you some help with the wiring? Sometimes two heads are better than one (even if both of you aren't quite sure of what you are doing).


There aren't many problems that cannot be sorted out with the help of the forum, even the wiring!
Even if it means going over it wire by wire....
If the wiring is really bad then strip it out and fit a new wiring harness as it just isn't worth trying to repair something like that if it has been badly chopped about. If you get somebody else to do it then there is still no guarantee it will be right.

probably of no consolation whatsoever Coco, but wiring is the one job I dread, ever more so than gearboxes.
If you do have to go to an expert for help I wouldn't feel obliged to seek out a Brit bike "expert". The wiring on these should not be beyond the ken of any competent bike repair shop.
Don't let it get you down mate, keep it all in perspective. A bike shop will most likely have it sorted in a coupla hours even if it might take the likes of you and I a coupla days.
Once it's up and running you'll forget all this heartache and just revel in the joy of that beauty of an engine.
millard

Thanks L.A.B. There is a Norton expert here in town, who offered to help with what ever I need, problem is he is away for another month. I could wait but I don't want to. I wanna ride!

This forum has helped but I've never been a "wiring guy".

Things are pretty messy. The whole positive ground thing has me scratching my head although it should not since I simply ground the red wires and not the black. One would think anyway.

Just wiring in the new voltage regulator, replacing the old rectifier is giving me a headache. Not to mention the old warning light assimilator which I am told will be replaced with something installed in the headlight shell (it has not showed up from CNW yet as it was back ordered).

After removing the old starter, the left screw holding the starter in, where the hole is cast into the inside of the inner primary is broken!!! It seems as though a previous "mechanic" has simply tried to re weld it and then JB weld it back in place. Some twit probably torqued the starter mounting screws way too tight (the screws were stripped very badly). The new starter will still go in but I have to make sure that broken piece is butted up against the starter and inner primary. When I pulled out the old starter motor, an aluminum spacer or washer fell out and I assume it was used as a spacer. Is this normal to have bolt or screw spacers between the starter motor and inner primary? Another nightmare.

I'm unsure if a forum can help me solve this mess I've gotten myself into.

I could wait for that guy to get back and help me with the wiring and get my wheels built up in the meantime, and possibly rebuild my front forks but the weather is nice and I'm freaking out and being impatient. I'm sick of driving a car while my friends go on rides with out me.

I will eventually get a new wiring harness made, but I don't want to shell out the cash for that right now as I will attempt or pay someone to rewire the thing entirely and more simply next winter when the motor is out for a rebuild and the frame gets powdercoated.

Oh the frustration.