Alternator Mount- Brush holder

[Jens_L]

As I am reassembling my engine, I decided to immediately swap out the breaker contacts for a digital ignition ( Silent Hektik).
Since I'm doing a full engine rebuild, I don't really have any reference if this would be OK or not:

The Silent Hektik ignition, has a rotor as well that you need to mount on the rotor of the alternator. So after assembling the primary drive, I mounted the timing cover and put the  (alternato)r rotor on. Now, when I put the stator on the timing cover, I noticed the brush holder isn't level with the rotor of the alternator. Which means I cannot mount the ignition rotor as per instruction of Silent Hektik. I did some research but didn't find any issue whatseover on this matter.











I could think of several solutions to this problem:

   - Milling down the recess in the timing cover ( which would probably be the most elegant solution)
   - Mounting the pick up with a washer ( but that would mean the rotor of the ignition would be farther away from the pick up, which isn't a great idea unless I mount it with washers as well)

In general I want to make sure I didn't do anything wrong in the assembly process, because one cause could also be that the crankshaft isn't positioned right ( too far back) which I would find odd as the pistons and cylinders are already mounted in place. I really really tightened the crankshaft's locking nut as well so that shouldn't be the issue.

Anyway, I'm looking forward to any opinion regarding this matter!

 

[Frenchfrog]

I'd get straight back to Silent Hektik.

[jamesb]

are you sure that you have the correct kit for your model alternator. i have been looking t the fitting instructions and there appears to be options.it is early in the day to start modifying

[Jens_L]

I'd get straight back to Silent Hektik.

Unfortunately Silent Hektik doesn't really reply to private customers, as they require you to buy from an intermediate supplier.
But my guess wouldn't be there would be a problem there since everything should be flush.

[Jens_L]

are you sure that you have the correct kit for your model alternator. i have been looking t the fitting instructions and there appears to be options.it is early in the day to start modifying

I got the Z2146I kit, which is the bosch kit for twin spark engines ( which I have heads for).

[Frenchfrog]

get back to the seller then. I would be astounded if any machine work is required.

[RinkRat II]

       Greetings Jens, Are the crankshaft and alternator original to this engine?

        Paul B

[Jens_L]

       Greetings Jens, Are the crankshaft and alternator original to this engine?

        Paul B

Honestly, I wouldn't know, the wear marks on the alternator rotor would suggest they had been running like that in the past. I did have 2 other timing covers lying around and I measured the recess 2.7mm and 3.3mm, which is quite the difference as well. It made me wonder if there were different batches of alternator stators and timing covers.

[Matt Story]

I've been interested in the silent heltik dizzys.  Inquired with them.  They were pretty much rude in their responses.  On each attempt to ask for information they answered with a very minimum of information.  I asked them to ID a us distributor.  There are none.  Had to ask again to ID a dist in the EU that would sell to the US.  They did not know and would not provide me a list of EU distributors so I might do my own investigation.  Pretty much ready to forget them.

Who did you buy from Jens?

[Jens_L]

I've been interested in the silent heltik dizzys.  Inquired with them.  They were pretty much rude in their responses.  On each attempt to ask for information they answered with a very minimum of information.  I asked them to ID a us distributor.  There are none.  Had to ask again to ID a dist in the EU that would sell to the US.  They did not know and would not provide me a list of EU distributors so I might do my own investigation.  Pretty much ready to forget them.

Who did you buy from Jens?

Hi Matt,

Since I'm in Europe, I ordered the Silent Hektik at TLM in the Netherlands, they were extremely helpful (they are not the cheapest for sure). I'm sure if you contact them they would or ship it to the US themselves or provide you with a contact that would do so.

My best guess would be that Silent Hektik is a very small business that employs very knowledgeable technicians, that have to answer the customer emails themselves. Hence there is no time to answer every e-mail in a 'good way', thats why they work with distributors.

If you wouldn't be able to get the parts via TLM, please contact me, we will figure out a way!

[Old Jock]

I don't want to rain on your parade but wasn't it a Silent Hektik ignition system that burnt a friend or customer, I cannot remember which, of the illustrious Dr Roper's bike to the ground?

Then on the other side of the coin I know of a buddy I ocassionally rode with who had one and never had any problem.

Should also be rembered that was some time ago so perhaps the system has been updated

I just want to make you aware, if you aren't already, that wasted spark systems on Guzzis can be probelmatic, the wasted spark can result in blowback through the inlet valve depending on the configuration.

Not a problem when the revs are up as the flame will simply be reingested, at startup though it may result in a carb fire.

If the wasted sprak occurs 360 degrees from when the cylinder requires ignition you should be fine, if it occurs when the other cylinder requires a spark it can result in blowback.

I'd test the system to know which type I had.

I'm not putting a downer on it per se, I'd just like to make you aware of the risk to ensure you mitigate against it and as I already stated a buddy had one that never gave him any trouble whatsoever.

[Jens_L]

I don't want to rain on your parade but wasn't it a Silent Hektik ignition system that burnt a friend or customer, I cannot remember which, of the illustrious Dr Roper's bike to the ground?

Then on the other side of the coin I know of a buddy I ocassionally rode with who had one and never had any problem.

Should also be rembered that was some time ago so perhaps the system has been updated

I just want to make you aware, if you aren't already, that wasted spark systems on Guzzis can be probelmatic, the wasted spark can result in blowback through the inlet valve depending on the configuration.

Not a problem when the revs are up as the flame will simply be reingested, at startup though it may result in a carb fire.

If the wasted sprak occurs 360 degrees from when the cylinder requires ignition you should be fine, if it occurs when the other cylinder requires a spark it can result in blowback.

I'd test the system to know which type I had.

I'm not putting a downer on it per se, I'd just like to make you aware of the risk to ensure you mitigate against it and as I already stated a buddy had one that never gave him any trouble whatsoever.

I realized that it was a wasted spark system, but many others work the same way ( Sachse), I'm guessing that it shouldn't be a problem unless valve overlap is 'huge' ( since the inlet  valve needs to be open to be able to blow back into the carbs) I don't know what camshaft the burnt bike had, but I would estimate it would not be a stock one whatsoever.

[Old Jock]

I don't know what cam was in the bike that burned to the ground Jens.

I experienced frequent blowback when my stock LM 1000 engined bike ran a Lucas Rita, where both plugs fired when one required a spark, fortunately never at start up.

The Sachse system uses a double trigger single rotor design, I know nothing of Silent Hektik, so the wasted spark is 360 degrees from when it's required a safer design, it's the system I have installed now

I'm not saying one system is good the other bad, I only wanted to alert you to the danger of a particular configuration of wasted spark design on the Guzzi big blocks (I know nothing of small blocks)

John
 

[Don G]

The Chicken Little response to dual spark ignition is best heeded by people who have spigot mounted carbs. flange mounted not a problem. I have run more than a few big twins with a single point distributor and a Harley coil to no ill effect.  DonG

[John A]

Foam filters will burn easier than gauze filters.  Intake fires on start are usually best handled by completing the start and increasing the revs. If it won’t start you gotta get off the bike and go look for a fire extinguisher or sand… gets exciting.

[Jens_L]

I actually tried again and the closest I got (with another timing cover) was this

[RinkRat II]

         Just throwing this out there, but it appears the fibre washer behind the brush mount is too thick. I imagine it is an isolator for that assembly and a thinner bakelite washer could be used. More $.02

     Paul B

[jamesb]

i am looking at the fitting instructions for bosch alternator. it doesnt look to be mounted the same as yours.http://www.motoguzzisales.co.uk/pdf/MG_Guzzi%20kit%20%20type%20%20fitting%20instructions%20-%20English%20Copy.pdf  need to copy and paste to browser

[Jens_L]

I was looking into some fitting instructions for alternator replacements, and found this:

https://www.boxer2valve.com/Merchant5/instructions/1231102.pdf

On page 12 of the document, It is exactly the situation I am in. I wonder if it could be considered 'normal' since as long as the brushes make contact it doesn't really matter that much in the situation. But for the SIlent Hektik ofcourse it does matter.

[Frenchfrog]

What do the people at Teo Lamers say? very experienced mechanics and they must have fitted many hundreds of these ignitions over the years...so if someone knows the solution I 'd bet it's them.Just saying...

[jamesb]

looking at other guzzi alternators similar to yours. yours appears to be correct. all the pictures have the brushes riding high on the commutator and the holder looking as though it is proud of the commutator
is the supplied pick up reversible?

[Jens_L]

What do the people at Teo Lamers say? very experienced mechanics and they must have fitted many hundreds of these ignitions over the years...so if someone knows the solution I 'd bet it's them.Just saying...

Actually they were extremely fast in their reply. They added a picture of how it should be



That it appears to be very strange, in their opinion the rotor should be further forward. Which I feared.

[Frenchfrog]

Good man... shame the lads at TLM didn't send you a side ways photo or measurement of the clearance between the trigger plate and the brushes/stator.It looks to me that you need a thick shim under the plate ...or the plate is the wrong one/ defective in some way.I'd go back to TLM and ask for some photos of the Guzzi trigger plate.The rotor and stator look right from here as the brushes run right on the rotor tracks....that means that it has to be an issue with the Silent H parts or something is missing.Could well be the trigger plate you have is for  a Saprisa or Ducati alternater which were fitted to Guzzis too.

[John A]

Is the stator seated correctly? On the pic it shows the stator winding part is not fully seated in its holder. Hard to tell

[Kiwi_Roy]

The Chicken Little response to dual spark ignition is best heeded by people who have spigot mounted carbs. flange mounted not a problem. I have run more than a few big twins with a single point distributor and a Harley coil to no ill effect.  DonG

So the message is hinting that you can blow the carb off?
Most engines i'm aware of with wasted spark fire just before TDC on the exhaust stroke, I can't imagine what happens if the spark is firing 90 degrees earlier or later depending on which cylinder it is wouldn't it be sparking at just the wrong time?

[Jens_L]

So as I was getting fed up with not knowing what was going on, I got my hands on a spare motor and started measuring.







My engine: distance from top of the alternator rotor to the timing cover: 76,75mm
                Width of the stator : 46.68mm

Other block: "" 77,31mm""
                   "" 46,31mm""

Which means there is just one mm of difference between the two, and that makes sense. So 0,56 mm of difference between the two crankshafts ( or between the alternator rotor, but i can't get the other one off).

If I put a shim underneath it looks good I guess.

[Jens_L]

Oh, and I have bent the alternator removal tool whilst trying to remove the other alternator, does someone have an idea how to get a really stuck one off?

[Tom H]

There have been threads about stuck rotors. Some did not end well for the rotor.

The main thing that normally works is to tighten the tool very snugly, you don't need meter long cheater bar. Then give the head of the tool a good sharp rap or two with a hammer. This normally results in the rotor flying half way across the garage.

Another option with the above, maybe use a heat gun. Heat gun, not a torch.

If your tool is shot, a very hard steel rod, like the shank of a drill bit can be used. Then just screw a bolt down to it. But it has to be hard or you mushroom the rod and play hell getting it out. Search for BMW alt removal.

Good luck,
Tom

[moto-uno]

  FWIW , I ran a Lucas Rita electronic ignition on my much modified Le Mans 2 (first the B-10 cam and then the Mega Cycle 620 , similar to the Norris SS grind )plus
40mm Dell'Ortos and never suffered from any spitting back ! Did you ever try the European jetting on your LM1000 ?  Peter

[John A]

So the message is hinting that you can blow the carb off?
Most engines i'm aware of with wasted spark fire just before TDC on the exhaust stroke, I can't imagine what happens if the spark is firing 90 degrees earlier or later depending on which cylinder it is wouldn't it be sparking at just the wrong time?

For me it’s after a failed start attempt, occasionally when it was hot, aftermarket cam & stuff. On early EV series they had a recall to add a closing throttle cable for when it pops back and it pushes the throttle body back and the belcrank would get fouled up not letting it go to idle. Surprise!  But that’s with a stock engine