750 points and electronic system?

TeddyG

TeddyG

Hero member
Location
Portland Oregon
After adjusting the points on my 750 I see that one is almost worn away. Since these are apparently not available I have to consider an electronic substitute. It appears Ignitech and Moto Witt are the 2 choices, so I,d like input on those who have installed them. My concern is ease of installing, clear English instructions, and support. Pity there isn,t a substitute for the old points system from an old VW, Porsche, BMW, etc, equivalent.
Thank you
 
Probably worth paying for the ease of plug-and-play Ignitech from Redax. Red has done all the hard work of designing and manufacturing the necessary bits for a simple setup and supplies everything you'll need. Not overly heavy stuff, so shipping from Australia won't be prohibitive.

Paul M may yet offer you a supply of replacement points! I'm sure there are ways to secure something new and workable.
 
Just received an Ignitech ignition from Red for the SFC. Nice bit of kit.
Will be awhile before I install it as house building is priority atm.
Will install over winter when I recommision the bike after it spent too many years in slumber mode.
 
I believe there are Bosch points available that need modifying, VW??
I like the idea of set and forget.
I found when riding,
the SFC was more susceptible to not having perfectly set timing than any of the Sfs I've owned
Hence the Ignitech upgrade.
 
OK then, in black and white Paul Marx, tell us where we can buy points for 750's ??? or an alternative that will work with a bit of filing, grinding, drilling, or general faffing around.


Not that I need them, my Egli has a Boyer Bransden system on it, modified from a Commando and long before Phil got involved with them, (Bransden that is) the trouble is this though, the system does not advance far enough , and maxes out at about 5,000 rpm, then constant but "flat" until rod busting level, I need that extra advance, I might even go back to points with an electronic setup that uses the points as very low current switching gear.
CLEM
 
Last edited:
CLEMTOG said:
OK then, in black and white Paul Marx, tell us where we can buy points for 750's ??? or an alternative that will work with a bit of filing, grinding, drilling, or general faffing around.


Not that I need them, my Egli has a Boyer Bransden system on it, modified from a Commando and long before Phil got involved with them, the trouble is this though, the system does not advance far enough , and maxes out at about 5,000 rpm, then constant but "flat" until rod busting level, I need that extra advance, I might even go back to points with an electronic setup that uses the points as very low current switching gear.
CLEM
Click to expand...
You must have good memory Clem..I havent seen the Egli run in the 20 odd years I have known you!😂
 
CLEMTOG said:
OK then, in black and white Paul Marx, tell us where we can buy points for 750's ??? or an alternative that will work with a bit of filing, grinding, drilling, or general faffing around.


Not that I need them, my Egli has a Boyer Bransden system on it, modified from a Commando and long before Phil got involved with them, the trouble is this though, the system does not advance far enough , and maxes out at about 5,000 rpm, then constant but "flat" until rod busting level, I need that extra advance, I might even go back to points with an electronic setup that uses the points as very low current switching gear.
CLEM
Click to expand...
Off hand, I don't know Clem since I don't need to buy any. Original types are unobtainable but alternatives exist, that's how we're going to have to get used to keeping our Laverda running. How do you think that riders of vintage and veteran bikes do?
Andy Wagner sells adaptable points and I know you can find replacement contacts that you can rivet on to the original spring.

Search bike shows.
Or maybe look around here or anywhere else dealing in parts for long gone models of long gone marques.

Benvenuto/a su Olimpiaparts (puntine)

. Leggi tutto
www.olimpiaparts.eu www.olimpiaparts.eu
 
CLEMTOG said:
OK then, in black and white Paul Marx, tell us where we can buy points for 750's ??? or an alternative that will work with a bit of filing, grinding, drilling, or general faffing around.


Not that I need them, my Egli has a Boyer Bransden system on it, modified from a Commando and long before Phil got involved with them, the trouble is this though, the system does not advance far enough , and maxes out at about 5,000 rpm, then constant but "flat" until rod busting level, I need that extra advance, I might even go back to points with an electronic setup that uses the points as very low current switching gear.
CLEM
Click to expand...
Had contact with Phil Todd post retirements, premise was the "Todd system" under advanced, i could not accept that was the whole story. So it was, Bransden ignition from Phil had a different crank timed advance over the usual British cam timed generic red boxes. Cam timed boxes were bought and installed bypassing Phil, then Phil got the blame when those fakes were demonstrably under performing.

As your aware Clem, points are at the end of a chain, its the advance mechanism doing the actual timing, therein lay the efforts required. Used a distributor mapping machine, college i worked at had 5 in Automotive Engineering. HTH j.
 
I see benefits to both systems and after some painful past lessons, I've learned that "if it's isn't broke don't fix it". I also am no points expert and attached is a pic of them. They appear thin to me but I may be mistaken. A friend has claimed it's possible to re-attach the pads that are apparently riveted in place. I see a rivet on the "arm" that pivots, but on the base, just a depression and hard to see how it's attached.
If possible, I would like to either replace or flip around the wiper pad before the metal tang makes contact w/ the shaft.

After getting input here and elsewhere, I'm considering either the Moto Witt or Saches units, but open to keeping the points for now if they are still operable.

Thanks again!
 

Attachments

  • points.png
    points.png
    1.2 MB · Views: 47
Look good to me, points, ( some have a spike wear ie migration of material one side to the other ) last you the life of the engine..... check the centrifugal mechanism behind the points, more important than these points ( which are serviceable in use ). Dial back timing light is going to help a great deal. Would not go the electronic route if mine. Transistor Assist ( TA ) system if you must should the auto advance be in reasonable condition. HTH j.
 
Thank you iis-iis,
I'll keep them- please explain checking the centrifugal mechanism. Per the Green Book I checked the timing w/ a light bulb that came on @ 1" before aligning w/ the TDC marks.

Is it possible to replace or flip over the wiper before the metal tang makes contact w/ the shaft?
 
The Phillips head screws fixing the points to the plate aren't original. The backing plate thread is easily stripped. Have seen self tappers used as a replacement, dodgy as!!!
 
Not sure about the degree of wear on the plastic buffer/actuator to cam lobe amount of wear, if that is what you mean, there may well be means to fabricate something to replace or mitigate the degree of useful life remaining.

The wear will effect the actual span of adjustment available would think. The cam lobe is driven by spring retained weights ( condition of bearings/bushes is important ) it is not driven direct from the cam shaft take off ( if the case and not the crank ). The velocity of the centrifugal mechanism will "advance" the ignition to a maximum of around 32DBTDC, static timing is not all that important at cold crank start and idle rpm. 5-8DBTDC is adequate. You will not have a working figure without a timing light, not expensive and remove any mystery on what condition the advance and points are operating under.

Dwell, this is one of the great hoaxes to be not endured in this day and age. Dependent on ignition coil type, though a working figure of around 3-5milliseconds will achieve coil primary saturation. Say 7000rpm ( all advance should be had by 4000rpm ) assume cam shaft operated speed, 3500. 3500/60 seconds, 59 revolutions per second, 17mS for one revolution, 17/3 equals say 6 or about 15% of the cam to points being closed to saturate the coil primary. As you can see, the actual points gap can be very low and still achieve operating ignition. The wider the gap the less time for saturation available, ie the buffer block or blade can wear a lot before it is not acceptable, HTH j
 
Std max adv on SFs is 40 deg. Easy to pull the advance unit off (two 8mm M4 screws), remove circlip and cam comes off. Clean and lightly grease. Check centrifugal arms for free movement and minimal wear.

When Suzuki introduced Nippon Denso elec ignition to the GS series in about 1978 I bought an advance unit, backing plate with induction magnetic pickups and little electronic CDI(?) 'box'. I then machined off my points cam and 680 Loctited on a cut down trigger, machined down the GS backing plate and fitted it into the sidecover and wired it through the elec box. Never missed a beat in about 160,000km, probably more. Set and forget. It was a dead easy conversion. So it roughly retained the advance curve of the SF but eliminated the points.

Actual rate of advance and max advance may have been altered but these are easy to modify or adjust on the SF advance unit (increase spring tension and fill and modify the hole that controls max advance). Of course, finding the GS ND parts these days is probably as hard as finding SF poin!s!
 
You must log in or register to reply here.
Back
Top