Sabotage

Greetings from Namibia,

I am writing this in the hopes that the forum users will give me some guidelines to fix a problem, Here's the short version of this sad tale of woe. I hired a older gentlemen to work on my commando, he needed the work, had the skills (or so I thought) he and his wife had fallen on hard times. Anyway, he got the bike pretty well reassembled and hit me with a eye watering bill. Truly absurd, but not out of character. I reacted badly as one is prone to do when getting boned in in the ass. Told him I wasn't going to pay it all and a few days later went to collect the bike. The gentlemen in question has since died from cancer and I am working with a mechanic friend of mine trying to get to start.

Matt at CNW has been very helpful in trying to give us guidance on trouble shooting.

Here's a list.
We have solid spark, 20kv measured.
new ignition Boyer
New battery,
Coils,
Capacitors
Diode
Harness
Plugs
Plug wires
Mikuni 34mm with 1 into two manifold

The timing has been checked repeatedly

We get an occasional backfire and nothing else.

There is gas in the cylinders

Towing behind a car did not start it. (old legs)

Checked the rockers they all lift the same.

There is no obvious reason for why the bike is not running, if only running badly. it just wont run. period, full stop.

At Matt's suggestion we took the right case off to inspect the cam chain and make sure it was properly aligned. (it was)

In doing this inspection though, it exposed the two leads to the Boyer that run through the case, dead guy had taken a razor blade and sliced off the insulation and exposed bare copper to the case. Clear evil sabotage.

We fixed it but the bike still wont start.

So now the quandary is this.

What other little things has dead guy done that are impossible to see or alternately even though we are getting spark, has the bare wires damaged the Boyer system, or some other component in the electric system?

I live in the middle of nowhere. Access to anyone who has any knowledge of old English is non-existent. Except in South Africa via an extremely lengthy and very costly export/import process to send the bike there.

I really would like to get this old girl running and on the road, but at this point I am at the end of my rope. Short of buying a completely new electrical system, including the harness i don't know what to do.

Any help would be deeply appreciated.

No start and occasional backfires sounds like the ignition timing is slow. Loosen the rotor and turn it CCW about 10mm at the edge and give it another try. Jim

Carburation maybe? If you have not already done so, I suggest that you strip the carb, and record all the jets and settings in the carb. I know it is a single Mikuni. Would not take long and if you post the settings here the Mikuni users will tell you if you are in the ball park

When I rebuilt my Commando(it has a single 34mm Amal mk2), it just would not start, and fired back through the carb, backfired, sometimes gave a few revs then died. I've had to change the float level, and both the pilot jet size and the choke jet size to get it to start and run properly.

Just something else to consider?

Peter

After you are done figuring out your electrical problem, maybe there is some real sabotage to the motorcycle that you should also check. For instance maybe he put sugar in the fuel and/or in the oil. So I would definitely change and flush all of the fluids (i.e. engine, fuel, gearbox, forks, etc.) in your bike before starting it and riding.

Many years ago I overhauled an engine for someone that had sugar put in his oil. It basically turned the oil into thick grease that the oil pump could no longer pump and flat out ruined the engine.

I also overhauled another engine for someone where someone had put sand in the engine. It did some serious damage as well.

So beware!

namibchris said:

The timing has been checked repeatedly

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Can you describe the procedure of how that was done, as a common error with electronic ignitions is to set them up using the wrong alternator rotor timing mark as there are normally two timing marks 180 degrees apart, if timed to the wrong mark, that will set the ignition timing out by 180 crankshaft degrees.

Connecting the pickup wires to the Boyer box the wrong way around will also throw the ignition timing off.

http://www.boyerbransden.com/pdf/KIT000 ... 00017_.pdf

Oil has been changed a number of times as we have worked through the issue and the carb has been cleaned and the tank as well so there is no evidence of sugar, sand or any other shit in the fluids. The US based gentlemen who sold me the Carb sent it with the wrong jets. So working with Mikuni South Africa I organized a new set of jets. The needle is currently set with the clip in the middle of the 5 available seats. I'm not the most mechanically inclined but with a Boyer ignition (no rotor) I presume that we can adjust the plate a few degrees from specified per Jim's Suggestion? Thanks guys, its nice not to feel so lost in the wilderness.....Chris

My first thought was timing is a rotation out (i.e. sparking on the wrong stroke)

Can be hard to spot if someone else has set it up, and you haven't pulled it apart yet

The timing was set following the Boyer instructions. Set using the timing marks and just on the chance it was wrong rotated 180 degrees and tried again, no change.

namibchris said:

I'm not the most mechanically inclined but with a Boyer ignition (no rotor)

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What do you mean when you say there's "no rotor"?

namibchris said:

I presume that we can adjust the plate a few degrees from specified per Jim's Suggestion? .....Chris

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That may be the case, but if the rotor (yes, you have one) was set too far from spec, it will have to be reset.

I would do this anyway, along with anything else that may be in question. I doubt the man committed sabotage, may he rest in peace, but you still need to know where you are at as far as mechanicals are concerned.

I think the worst of it might be a mis-timed cam. Let's hope not!

Ok the next step will be to advance and retard the timing, and yes I while I hope dead guy rests in peace he was fully capable of screwing with the bike out of spite. As exhibited clearly with shaving the insulation of the wires leading to the Boyer ignition.

My first guess would be the Boyer stator wires need to be reversed. Strange things happen if you do not get this one correct.

I don't think you can time a Boyer on a Norton twin 180 degrees out of phase because of the wasted spark feature of the Boyer/Coil system.

Didn't you agree some sort of price for the work before he started it then Chris?

Dances with Shrapnel said:

I don't think you can time a Boyer on a Norton twin 180 degrees out of phase because of the wasted spark feature of the Boyer/Coil system.

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Yes, you can, as the Boyer fires once every 360 degrees of crankshaft rotation, not every 180 degs. That's once every 180 degrees of camshaft rotation.

L.A.B. said:

Dances with Shrapnel said:

I don't think you can time a Boyer on a Norton twin 180 degrees out of phase because of the wasted spark feature of the Boyer/Coil system.

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Yes, you can, as the Boyer fires once every 360 degrees, not every 180.

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The OP did say "timing was checked repeatedly" (presumably strobe to timing marks). You are correct; I was thinking rotor magnet, not crank angle.

Dances with Shrapnel said:

The OP did say "timing was checked repeatedly" (presumably strobe to timing marks).

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But it can't be strobed accurately until it's started.

As mentioned in other posts:

Things to check:
- Cam timing via sprockets and index marks.
- Ignition timing and function. If you can, just swap an actual points/advancer setup in there. Would not cost you much to get it to start on that.
- Post jetting on the VM. Might just be that you've got a WAAY too rich pilot jet. Are the plugs wet after kicking?
- Check the plugs themselves. Right plug? Clean? Gap?
- Check the plug wires to make sure the wires and caps are both not resistive

Have you done a compression test on it?

Yes I agreed to a price.

It came back double.

Dead guy was a heavy drinker but unknown to me when he got his diagnosis, he went off the deep end.

We will investigate the timing and the stator wires asap.

one last question ho much damage could have been done to the Boyer Ignition by the exposed copper in the power leads? Is there any point to trying any of this in this light? is it not possible that it has been damaged and wont work properly?

Thank you very much for the observations.

Chris

L.A.B. said:

Dances with Shrapnel said:

The OP did say "timing was checked repeatedly" (presumably strobe to timing marks).

Click to expand...

But it can't be strobed accurately until it's started.

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Accuracy with a strobe while kicking is a non issue. It is good to see if it is in the ball park and a strobe triggers at spark and it should show where you are getting spark for starting purposes.

It is not the normal way to initially set up a Boyer but it is a valid check.

Other's are helping with your technical issues but please don't try to tow the bike behind a car to start it. Just too damned dangerous. If you can't start the bike with the kick starter something is set up incorrectly. You need to find out what it is and set it right.