Recommend electronic ignition for 750
- Thread starter smlav
- Start date
That's because lawn mowers, like a lot of things need to be mass produced and sold to even the dumbest.
That's the way Laverda was going, but the firm collapsed before they produced the motorcycle for numpties which we see on every street corner now. Allows the marque to keep a certain aura nowadays which it would have without doubt lost.
Paul
You're not alone on this forum.
Paul
Will you use it a lot?
Paul
motoddrob
Hero member
- Location
- S/W Australia
6-8 track days a year
Has anyone developed an Ignitech Ignition Curve for twins yet? Q? Mine was done on a club ride to the Bylong Valley much to the unhappy faces waiting at various stops while Brett attached his Laptop and asked me how the change was ever 50ks or so. It was surprising to feel the effects. It took a good while to get it effective right through the rev range. For a while it would be strong down low and weak up top and visa verse. In the end it was impressive how seamless it ended up. Add to that my very odd engine setup that probably didn't transfer well to other engines all the while being careful not to get into pinging territory. That was years back, I guess the collective knowledge of curves to suit various engines is now down pat.
Last edited:
Seems todays small internal combustion aero engines still use magnetos as the primary ignition choice, but breaker points have been largely phased out. CDI systems, basically like that originally used in Lav triples, seem to be quite common, but doubled up to comply with aviation regulations. Fully digital motor management systems are also in widespread use.
After decades of being the sole spark suppliers in aviation, contact breakers have been ditched for something more reliable and less maintenance intensive. Can't be THAT wrong to fit a modern system to bikes then...
piet
CLEMTOG
Hero member
if they did it in light aviation, as Piet says, it must be a good thing, because the rule in light aviation is that of never wanting to change something that works, until very recently their was a lot of light aviation coming out of Biggin Hill, many 30 or even 40 year old Cesnna's etc its barely 3 miles from here as the crow flies, during and since Covid that has basically stopped, the most aeroplanes that I see overhead of my house are now single or two seat Spitfires, with a Cessna spotter plane (sometimes) and thats about it, In the cafe at the airfield you could not see accross the apron for parked light aircraft, now there are just, maybe, five, instead of lterally dozens, where did they all go? magnetos included, its the same with commercial aviation, before Covid at 7 am when the main airports fully open, (Heathrow is only allowed 8 flights per night) the sky (on a still day) was like a patchwork quilt, now at 0700 to 0730, you see two, maye three, we all know where those planes are tho, in Gloucester, you cant get another Jumbo on the ground because there is no space left!
CLEM
CLEM
Alzero
Hero member
- Location
- DaNang Vietnam
Would the lack of air traffic reflect the local economy? General Aviation is quite expensive and vacations can be too, even with a cheap air ticket.
piranha-bro2
Hero member
- Location
- Melbourne
I set up a basic curve, Vince and have really not had to change it much - I had greenhorn (me) issues initially getting my head around base advance and not being able to correct a discrepancy between left and right, but the curve is nothing special - the motor just has a big fat torque curve with no dips at all from 3500-8000 but a couple of noticeable 'up' ramps as the cam and pipe come into play. On the dyno we found an extra 3hp by upping max advance from 32 to 35 degrees. Other than that I haven't felt the need to change it.
Zero chance of me fiddling, especially after I saw how easy it was to lose the file if you don't know what you're doing. Brett did it all, you could notice gaps between changes to the curve till the next change filled it in, by gap I don't mean fell on its face, just slower acceleration. In my case, the bike has the cam profile copied off the F1 cam for RGS in my 3c. It's got power in all the rev range. Best to talk to the brains trust on this.
minigunz
Junior member
- Location
- Ontario CALIFORNIA
Question
Need points for my 750 SF 1971 model, what VW model or part number did you refer to in your reply.
I have a left cylinder mis firing so it's new coils and points to see if that cures the issue.
I took a set to a USA auto parts store and looked at 1969 VW Bug points but they have a different
mount hole for the screw location. Any recommendations would be a great help.
Thanks guys
Jeff USA California
martymoose
Hero member
- Location
- Sydney, Australia
Points will probably clean up ok but a failed condenser will cause misfire. I would try and source a pair of new condensers first, points will probably last a long time
Points will be the last cause of a misfire unless they're dirty.
Check earthing of the condensers to the backing plate. If there's still rivets and if they're loose, you have a misfire.
Paul
For some clarity, the capacitor ( love the quaint term "condenser" relates back to condensing electrons inside a glass jar, metal foil inside and outside ). Function one, is to quench the arcing across the contacts or "points"... Contemporaneously, function two is the return path to battery negative. That is for a auto transformer type ignition coil the primary current and the secondary ionic current also conducted to battery negative or frame of motor. The capacitor actually starts charging from these currents increasing the effective impedance return path of the ignition coil, ie reducing available spark energies.
Hard life for a capacitor, cooked and flogged with surging currents and peak voltages. Am thinking have stated much of this prior, its an age thing, somewhat akin the being charged and discharged... seems so. HTH j.
Hard life for a capacitor, cooked and flogged with surging currents and peak voltages. Am thinking have stated much of this prior, its an age thing, somewhat akin the being charged and discharged... seems so. HTH j.
Exmoor beast
Hero member
- Location
- Minehead,Somerset, ENGLAND OF COURSE
You have to modify VW points by drilling out pivot pin. Coils VW , condensers I got from eBay , pretty much any set of condensers that will fit will be fine ( could ft them externally also) and new caps & leads. I had a misfire from the points, nut and bolt through flag was slightly lose, I mean 1/4 turn. Take them all apart and clean off all corrosion - your relying on tiny contact patches for current to flow.