Vega Double spark racing cylinder head

Hi there,
I join this forum for the first time so first hello everybody!
I'm from France so my english speaking may sound a little rotten..sorry for that.
I would like to know if someone has ever experienced the fitting of a double spark racing head on its Vega and if yes could he give some advices , infos etc about the ignition system it requires.

Regards

Welcome John. I've never seen one but there are plenty of tuning guys and girls on here that love finding more power. There have been some conversions using the 125 Special head as it has a central 'squish' this requires plugging and redrilling the stud holes to suit the Vega barrel spacing.
Paul

alan gardner will be overjoyed with this, hes said for years about a twin plug head, but no ones seen one before.
nice find john.

just shown Alan this, he says his old one was the same, and from rafferty newmans wildcat conversion.
both plugs never fired at the same time, one was for normal use the other for fast road use, one plug was 16mm thread size from a Honda 50 and the other was a standard21mm plug.

Hi John
That is a good find.
I can't contribute anything to the use of it but would imagine if you could run it with the new advance \ retard electrical system, it would make swapping between the plugs more beneficial.
Let us know how it runs please.

Heres another example


it was fitted to this old race scooter

great pics, first time ive seen one.

Hi,welcome.
I don't see how a twin plug on a single cyl would work? Unless as already said a different plug for separate uses. That said wouldn't timing be have to be different for each plug to gain anything of an advantage?

Very tidy. What is the rear shock?

I’m sure you exhaust will be of interest as there are so few options off the shelf for us Luna owners.

No experience of the timing for your set up I’m afraid

Are you planning to run without an air filter? That will obviously make a massive difference to your jetting.

Hi,-
The rear shock is a from a chinese brand named FastAce. You can find some on ali-express and on  websites dedicated to pit bikes. And also on ebay. Pitbikes use two differents kinds of rear shocks, some are positioned commonly , some almost horizontaly. The right kind for the Vega is the first type, as horizontal ones are usualy far more far too stiff ( around 1000lbs) and spring diameter bigger than the original lambretta schock. The right spring load rate for a lambretta scooter is more or less 300lbs. They usualy exist in different length and srping stiffness. Some are adjustable other are not etc..They’are truly beautifully made and unbeatable in terms of quality/price ratio. I bought this model a little less than 100€. The right length for the Vega is 295/300mm. This one was only 255mm long so i used an 40mm extender. 
The silencer i am planing to mount is from ali-express too and beautyfully made from stainless steel. It is  supposed to be a universal silencer for small capacity (50-250cm3). To be true i’m not 100% sure It will perform as well as the stock one but it is so special visually and fonctionnaly that it reall worth testing it!  require a alf U-bend pipe between exhaust manifold and itself. I will try to do the job in the coing days and will post pictures .

Hi thanks for the very detailed information on the shock. I know some of us on here have looked at pit bike shocks before but I don't think it came to anything because of one of length /spring diameter / bush sizes so interesting to see that you've over come these issues. I'm not in the market for one at the mo as I gave up and bought a remade casa one but interesting to see the extender that you built. It certainly looks very trick. How did you make that?

Also keen to see the pipe pictures. I think the stock exhaust is hard to beat looks wise - I loved flash Gordon as a kid - but I think they are quite restrictive so perhaps there is a good chance to improve things.

Hi again,
Did not have to built any part. These shocks extenders are common aluminium parts available on modern scooters webshops and on ebay as well . Some are better designed and finished than others and they are mainly available in 25-30-or 40mm lengths. 
Regarding the stock 75 exhaust i’m not sure it is as restrictive as its reputation. Just have a look at the attached file here under (taken from the vega tuning dedicated pages in the Ken Herlingshaw tuning manual )...
To be true I just found a great  looking silencer on ali-express which i thought would match the design of the Vega maybe even better than the original one (But will certainly look terrible on any other bike). Please just wait a few weeks and i will send you pics of it fitted on my Vega and i promise you it will look amazing!! I just don’t know before testing if it will perform well with my Vega configuration but it truly worth trying.

Fair point that. What way do you intend to compare performance levels between the two?

The scooter looks ace & you have clearly put time & effort in there! I hope it runs as well as it looks!
Great info on the rear shock, I didn’t know extenders existed! Love the front shocks too & very intrigued by the exhaust!!

Hi MickeyC
Thanks for your comments!
I’ll post the special exhaust once fitted on the bike. Maybe 2 weeks. It will be the final & unique touched!
Here attached the cylinder head i will fit after the running up time.

Wow! That looks really good I'm loving that green paint work. Top class work on this bike.

Thanks , i think this green is matching the vega design pretty well. A praying mantis !

JOHN KORDA wrote:Hi,-
The rear shock is a from a chinese brand named FastAce. You can find some on ali-express and on  websites dedicated to pit bikes. And also on ebay. Pitbikes use two differents kinds of rear shocks, some are positioned commonly , some almost horizontaly. The right kind for the Vega is the first type, as horizontal ones are usualy far more far too stiff ( around 1000lbs) and spring diameter bigger than the original lambretta schock. The right spring load rate for a lambretta scooter is more or less 300lbs. They usualy exist in different length and srping stiffness. Some are adjustable other are not etc..They’are truly beautifully made and unbeatable in terms of quality/price ratio. I bought this model a little less than 100€. The right length for the Vega is 295/300mm. This one was only 255mm long so i used an 40mm extender. 

I will use the original air box, i did the carb setting with it. It was certainly on the bench being modified i took these pictures.
. 

The silencer i am planing to mount is from ali-express too and beautyfully made from stainless steel. It is  supposed to be a universal silencer for small capacity (50-250cm3). To be true i’m not 100% sure It will perform as well as the stock one but it is so special visually and fonctionnaly that it reall worth testing it!  require a alf U-bend pipe between exhaust manifold and itself. I will try to do the job in the coing days and will post pictures .

Hi John, you dont have a link for the rear shock & extender looked all over Ali-express etc, but cant see one thanks S

Hi Sidhop , just go on ebay and search for “CRF50 shock” , you will find! !

Hi Sidhop,
Have you found a fastace rear shock? I did not receive my exhaust muffler from the welder , that’s why I did not post the picture yet. Hope it will come soon.

I just love that bike

Thanks Thackers
Your vega seems to look nice too as far as i can guess it through this small round picure. Is it original blue in color or a is it a slightly different shade of blue?

John - did you get the message that I sent you on here?