Advice for routing brake hose and wiring query help please.

I am in the middle of renovating my MK3 Commando, and wonder if anybody could help me as I don't have a parts manual for reference. I actually have two questions.

1. I have fitted an after market disc and caliper and have mounted the caliper behind the left hand fork (originally on the front of the leg as it is a Mk3) with the disc still on the left (obviously), and at present am looking for the best route for my Goodrige brake hose to route to my master cylinder. At the moment I have it coming up through the original metal bracket (into which I have fitted a rubber grommet) where the brake hose previously joined the metal pipe on the original construction, although I have also turned this around so that it also sits with the hole behind the fork leg instead of in front of.

The best route for the hose would appear to be straight up through the hole in the metal bracket, and then through the larger of the two holes found in the lower fork yoke, but what are these holes there for? Was it for a bracket to hold the brake pipe originally?

Any suggestions for routing from experience would be welcome, but at the moment this appears to give it the straightest run with a steady turn to the master cylinder.

2. I have bought a new wiring harness from BSA Regal. I am struggling to work out why one of the wires exists which is included in the group that runs down to the alternator/ neutral switch. After excluding the two wires for the neutral switch, I am left with a green/yellow, white/green, brown/blue and a solid blue! Why is the blue wire there? It has continuity with the solid blue which runs to the switch gear in the left and right switches and operates the headlights/main dip. In the wiring diagram it does show this wire running to no-where and says see note 1 which says "for the Canadian market." So does this just hang free?

Also I have a two wire 180w alternator. In what format are the wires connected?

Reggie

The earlier pattern brake lines were not simply a mirror-imaged reversed version of the Mk111 set up. There was a bracket mounted on the mudguard boss to take the junction of the flexible pipe to a short rigid length but of course the pipe did not need to run around the inside of the fork leg.

Unlike the Mk111, there was no rigid length between the fork yokes and the only purpose of the holes seems to have been to hold a rubber blanking grommet - Maybe they intended it for the brake lines or maybe for a steering damper ?

The hose from the master cylinder ran directly to the lower bracket and was held by two clips above and below the headlamp mounting "ears" A bit "pisspotical" really (to use a term learned from the NOC Service Notes) and if you are using stainless hose, you will need to sort out something better to avoid it doing an impression of an abrafile.

You're absolutely right on the blue wire (unless you live in Canada) Canadian models had a different warning light assimilator which made it impossible to ride without headlamp on (Incidentally, there is a chap in the UK who tries to sell NOS Canadian assimilators on ebay from time to time

I have looked at both my original Mk111 harness and my current replacement and they both have it taped away.

You can't go wrong with the alternator. They wires from the alternator each go into a triple block - One together with the two green/yellow and the other to the two green/white - It doesn't matter which way round.

Thanks 79x100.

So I assume then that the clips (which I think I have somewhere) for the original flexible hose went above and below the ear on the right hand side headlamp carrier, before the pipe then crosses over to the metal bracket on the left hand fork mudguard mounting and then connecting onto the metal pipe on the original design. Therefore if I understand it correctly, the rubber pipe crosses the forks from right to left below the lower fork yoke on the original design?

(In my post above I said "although I have also turned this around (the metal bracket) so that it also sits with the hole behind the fork leg instead of in front of." which is actually as it always was,. My mistake.

Yes, I realise that the Goodridge pipe will act very much as a file if I don't secure it appropriately. I just wondered if anybody else could offer advice as to how they may have done it assuming the caliper was where mine was behind the left fork leg.

With regards to the wiring, I understand that it doesnt matter which way around the green/yellow, green/white plugs into the alternator, but does the brown/blue wire plug into one or the other?

Thanks for the help.

Reggie

Reggie said:

With regards to the wiring, I understand that it doesnt matter which way around the green/yellow, green/white plugs into the alternator, but does the brown/blue wire plug into one or the other?

Click to expand...

There should be two brown/blue wires from the harness fitted to a single spade connector that fits to the centre terminal of the (standard) rectifier, no brown/blue should connect directly to the alternator output as this is AC.

You may also find another double brown/blue and a single brown/blue, these should connect to the double spade on the 2MC starting capacitor (blue coloured unit with a suspension spring).

The outermost hole in the lower yoke is where the lower flexible hose would normally connect and would be located with a nut and washer on the top, and the MkIII rigid pipe then connects to it.

I ran my braided hose to the rear of the lower yoke, then across in front of the headstock, it then comes out at the top rear of the R/H headlamp bracket just below the top yoke.
I fitted the original plastic spiral hose protectors over the braided hose.

Reggie,
My apologies for not reading your post properly. When you said you had turned things around, I thought you meant putting the caliper on the rear of the leg which would have meant on the right hand side. How have you managed to put a caliper behind the left-hand leg ?

The Mk111 does have a short rigid pipe which goes between a small bracket mounted off the warning light panel to the bottom yoke. A flexible pipe then comes up through the left-hand hole and runs down to the bracket on the slider.

Although it's fiddlier and involveds two lengths of hose plus two rigid sections, I replicated this system when fitting stainless lines to my mk111 as it seemed neater and reduces the possibility of rubbing.

Maybe a photo of your brake set-up would help. You can bet that most things have been tried by someone here.

I think that the brown/blue wire you are referring to (if there is also a red wire nearby) is for the electric shaver / airbed pump socket that no properly equipped Commando Owner would have been without at the time Nortons used to say you could charge the battery with it as well, but I wouldn't want to.

Thanks for the replies.

LAB says "There should be two brown/blue wires from the harness fitted to a single spade connector that fits to the centre terminal of the (standard) rectifier, no brown/blue should connect directly to the alternator output as this is AC. "

There are two brown and blue wires connected to the central rectifier terminal on my bike, so this matches up.

LAB says "You may also find another double brown/blue and a single brown/blue, these should connect to the double spade on the 2MC starting capacitor (blue coloured unit with a suspension spring).

On mine there are two double connectors, going to the capacitor, not a double and a single.

Thanks for the info about the brake hose routes that you have used. Do you know if you can still get the plastic spiral hose protectors?

Thanks again both of you.

Reggie

79x100 says "the brown/blue wire you are referring to (if there is also a red wire nearby) is for the electric shaver."

I have located these and already insulated and taped them into the wiring harness, as I will not be using them, so it isn't these wires.

Therefore after taping up the red and the brown/ blue for the shaver etc, I am still left with six wires bundled together.
1 x solid green and 1 x solid red for the neutral light switch.
1 x white and green and 1 x green and yellow for the alternator.
1 x blue for the Canadian market - to be taped up.
1 x brown and blue for ?

Do you think that this extra wire is supernumery, and possibly comes "extra" for some reason as I have two double connectors going my capacitor for some reason, instead of a double and a single?
If it is not to be connected to the alternator, I assume then that I should just tape it up as I will do for the blue(Canadian wire). What do you think?

79x100, I have managed to put the caliper behind the left fork leg, as I have fitted a Norvil fork leg, with what is officially a r/h leg which puts the caliper in front when fitted to the right hand side, and the rear when fitted on the left side of the bike.

Sorry but this should have gone at the bottom of my script not the middle. It's due to poor proof reading.

"Thanks for the info about the brake hose routes that you have used. Do you know if you can still get the plastic spiral hose protectors?

Thanks again both of you.

Reggie "

Reggie said:

Do you think that this extra wire is supernumery, and possibly comes "extra" for some reason as I have two double connectors going my capacitor for some reason, instead of a double and a single?
If it is not to be connected to the alternator, I assume then that I should just tape it up as I will do for the blue(Canadian wire). What do you think?

Click to expand...

This brown/blue does seem to be an extra (it could also have been something to do with the Police Interpol model spec??) so I would tape it up.

The necessary brown/blue wire connections are:

Battery Neg. terminal
v
v
Fuse
v
v
Rectifier
v
v
2MC>>>Harness multi-pin connector>>>Ignition Switch
v
v
v
Accessory Socket.



.

Reggie said:

"Thanks for the info about the brake hose routes that you have used. Do you know if you can still get the plastic spiral hose protectors? Reggie "

Click to expand...

I would give Nick Hopkins at BSA Regal a call. (They also do all the AP Lockheed stuff) or Mick Hemmings. If it can be used on a race bike, he is likely to know about it.

I have the brown/blue going to all of those places (LAB) and as a precaution have checked for continuity which of course is there, so it looks like it's redundant. If I ring Nick Hopkins tomorrow about the cable protector, I may also ask him about this wire as I got the harness from BSA-Regal. Unfortunately, their parts site appears to be still down, so I can't get info about part No.s.......I may have to buy a parts book!

Thanks both of you.
I may have a few more questions yet. I hope you don't get sick of me.

Reggie

Reggie.

There is probably a red wire from the harness with a ring terminal that looks as if it connects to the battery positive terminal?

If you intend to use the electric starter then DO NOT CONNECT THAT WIRE!!

Fit only on the heavy* starter cable (between the crankcase and battery + terminal) and fit an earth/ground (red) wire between the cylinder head and any red harness wire.

The reason being that if for some reason the heavy return wire becomes loose or badly connected (vibration?/corrosion?) and the electric starter is operated then the starting current (100+Amps) will take an alternative route back to the battery via the light gauge red harness wire !!

This can at least destroy the wiring harness and possibly cause a fire.

The Triumph Trident T160 was originally wired the same way, and a service modification sheet was issued to dealers instructing them to disconnect the red harness-battery wire, snip off the ring terminal and tape the wire back to the harness on all T160's.

*The standard starter cables should be upgraded to a heavier gauge.

Good Grief L.A.B., I didn't know that !

I took a hacksaw to my 'leccy 'tart many years ago so it's a bit academic but nevertheless, it's one of those things that a chap should know.

I never knew that. Just out of interest I've had two Commandos in the past both pre-electric start (well, one was my friends but I did a lot of work on it) and that relatoinship lasted for about 15 years with the bike that is,(although my friend owns both of them now) and I've just had about eleven years on German and Jap bikes before buying this MK3 in March this year.

Anyway to get to the point, I have bought a 06-4791/B "uprated" after market starter motor for this bike, and also the three heavier duty wires to go with it, although not fitted yet as cylinder head and one crankcase is away for repair. On the original solenoid there is an S and an I marking. There appears to be a white and red and a white and purple wire going to the solenoid from the wiring harness. I have been told to not connect the white and purple wire(at either end), only the white and red wire. Do you know if this fits on the S or I marked terminal?

Also if I may go on further, I was reading about the Boyer MK3 ignitions, of which my bike is fitted, and read that with a low voltage i.e. when starting the bike, it is likely to not fire correctly and could cause a kick back which could damage the start train. I think that it was the Pazon electronic ignition that was recomended, I just wondered if you thought that it was OK to use the Boyer mK3 or if it was a well documented folly?

"There are more questions than answers?"

Reggie

It's so long since I threw away my starter that I'll leave the wiring question for somebody else.

However, my reason for doing it does tie in with your last paragraph.

My Boyer-fitted bike back-fired on starting and pulled the hexagon off the sleeve nut which holds the anti back-fire device together. I didn't know why but having a dislike to bits of steel falling in my primary chain, I took the lot off.

I have since found that if a battery is on the way out, the Boyer will cause kick-back on trying to start.

Dyno Dave's site goes into some detail on this and it all seems to fit. Sooner or later it will happen and at the very least, turn your sprag inside out.

The late lamented Lucas RITA did not do this and Pazon claim that theirs doesn't. I'm seriously thinking of one to replace my Boyer.

Don't know if the digital is necessary / worth the money. Still need to investigate that.

Reggie said:

On the original solenoid there is an S and an I marking. There appears to be a white and red and a white and purple wire going to the solenoid from the wiring harness. I have been told to not connect the white and purple wire(at either end), only the white and red wire. Do you know if this fits on the S or I marked terminal?

Click to expand...

White/red wire connects to the 'S' terminal, the white/purple has no function if a Boyer (or other) electronic ignition system is used.
This wire would originally bypass the ballast resistor during starter operation supplying the original points (and 6V coils) system with full battery voltage (which can drop down to around 7-9 Volts during starter operation!).

And the low cranking voltage can affect the Boyer ignition system, causing the timing to advance during starter operation (kickbacks) and even during kick starting if the battery is flat!

Some Boyers seem to cope better than others with low voltage and my own 850 MkIII has a Boyer that seems to work OK when using the starter.

The Lucas RITA ignitions did not appear to be as badly affected by the low Volts as the Boyer system, although the RITA kit is no longer available.

The new Pazon type ignition has been designed to work at lower voltages and with the benefit of modern technology should be an all-round better unit (and at an all-round better price too!!).

Also ensure that the anti-backfire (kickback) device is correctly adjusted, this can help to save the sprag from self destructing! (although they generally do anyway!)
Also using the later type sprag helps (well I think it does!).

LAB says "Also ensure that the anti-backfire (kickback) device is correctly adjusted." Do you mean fitted correctly or is there an adjustment available? I cannot see any reference to adjustment in the manual.

Also with regards to your sprag clutch, are you refering to the Norvil "New type with more sprags" clutch. I have bought an original from BSA-regal and it appears to have 18 "bearings" or sprags. This appears to be the same No. as in the photograph of the "more sprags" clutch on the Norvil site. It sounds ominous for the future does this electric start system!

Thanks again to both of you.
Reggie

Reggie said:

is there an adjustment available? I cannot see any reference to adjustment in the manual.

Click to expand...

Yes this is adjustable.

I don't know which version of manual you have?

So, if it is the factory version then it doesn't seem to be mentioned in the specifications or text but if you look for diagram in Section C: "FigC52(a) Diagram of starter gear reduction (and drive track)" then you should see: *OVERLOAD "BACKFIRE" DEVICE TIGHTENED TO GIVE A SLIP TORQUE OF 50 LB/FT - 6.91 Kg/m.*


The Haynes manual also contains the same diagram in the MkIII supplement titled: *Electrical starter reduction gear train*

And also mentions in the text:
------------------------------------------------
*Backfire Overload Device

(1) The backfire overload device should not be dismantled since it has been preset by the factory.

(2) If the device has been dismantled, it must be preloaded on assembly to slip at a torque wrench setting of 50 lbs/ft [plus or minus] 2.0 lbs/ft (6.92 kg/m [plus or minus 0.28 kg/m]. The outer edge of the adjusternut must be peened over to prevent movement.*
--------------------------------------------

I cannot find any reference to the preload setting in the Clymer manual at all.

Checking the unit involves holding the gear (in a vice) and devising some method of applying a torque wrench to the shaft splines. I did this by putting short pieces of welding rod in the splines and jamming a socket over them. I don't know if there's a factory tool available I've never seen one?

If it needs adjustment then the peening has to be removed, and re-done after adjustment (which may of course not be necessary).

Shortly after buying my own MkIII the (old type) sprag destructed!
When I checked the preload of the A/backfire device I found that somebody had locked it up solid!!!

If the A/backfire device slips *occasionally* (you will know when it does by the clatter!) then it is doing its job, although some owners I believe, mistake this for the unit being under-adjusted and so tighten it up a bit which doesn't do the sprag any good whatsoever!!

Reggie said:

Also with regards to your sprag clutch, are you refering to the Norvil "New type with more sprags" clutch. I have bought an original from BSA-regal and it appears to have 18 "bearings" or sprags. This appears to be the same No. as in the photograph of the "more sprags" clutch on the Norvil site.

Click to expand...

Yes, hopefully the later 18 sprag unit is an improved part.

Thank you very much for telling me this, as I wouldn't have known how to pre load it by just reading the manual. I have the official Norton MK3 workshop manual, but it is very poorly written and not at all comprehensively explained, and as I said previously, this is the first electric start Commando that I have owned. I suppose when I would've been building this device from its component parts (hopefully in September) I may have asked for advice, we'll never know now, but I have had a look at the shaft, and I notice that the shaft has a channel to peen the shoulder of the nut into. I'll have to devise a way of locking the splines, although the method you devised sounds quite good

I bought the bike with the starter not on the bike, and was told by the seller with regards to the starter mechanism "it's all in there" (the primary chaincase), but it wasn't. A couple of the bits and sprockets were in a box along with the solenoid, and the starter unit itself was in pieces, therefore I have had to buy new probably 85% of the starting mechanism.

I greatly appreciate the information and advice.

Reggie