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Motorcycle Discussions => British Bikes => Topic started by: Vreagh on July 20, 2021, 11:33:38 AM

Title: Tuning villiers carb
Post by: Vreagh on July 20, 2021, 11:33:38 AM
When assembling a mk2 single cable Villiers carburetter, is there any set number of turns to the mixture control for the first start. It seems that when the cable in in place, the mixture can only be turned just short of a full turn. Or have I got this wrong?
Title: Re: Tuning villiers carb
Post by: 33d6 on July 20, 2021, 02:40:28 PM
I love these questions.
Do you mean that you have a prewar carburettor on a prewar engine? If so what engine is it?
I ask this because Villiers did some minor improvements on their original carburettor design and stamped ALL their carburettors Mk II from the late 20’s on.
As the Mk II was stamped on the float bowl which is interchangeable with the earlier type anyway, the Mk II designation isn’t that helpful.
Further to this Villiers used only a limited number of standard bodies regardless of engine but changed the internals around to suit, so for example a carburettor set up for a 150cc engine will clip straight on a 175 or 250cc engine but
won’t work well.
So, I’d like to help but what have you actually got? What Villiers engine are you playing with?
Title: Re: Tuning villiers carb
Post by: Vreagh on July 20, 2021, 03:59:59 PM
I'm using the carb on a 196 super sport engine (although at moment it has a cast iron piston). The carb may not be the original but I'm hoping to make it work. I followed your advice to another member and bought the villiers book. Unfortunately, I bought the wrong one, mine has C Grange as the author and I've found little info on setting up the carb. I've the Browning book on order.
Title: Re: Tuning villiers carb
Post by: 33d6 on July 21, 2021, 03:29:32 PM
I don’t know if the cast iron piston makes a great deal of difference to the carburation as it has identical dimensions to the correct alloy type including the shape of the crown. That’s fine in theory but you will soon find out why the world moved to alloy pistons whether the carburation is spot on or not.

The original factory carb set up for your engine is an MW carb fitted with a no 2 jet and a no 4 needle.

If you send a message with your email address I will send you an info sheet with all the relevant info you need for setting up the carb.
Title: Re: Tuning villiers carb
Post by: Vreagh on July 21, 2021, 06:25:10 PM
Pm sent, cheers.
Title: Re: Tuning villiers carb
Post by: 33d6 on July 22, 2021, 03:07:21 AM
Blurb on its way.

Now we've settled that one can I ask a question?  How many teeth on the engine sprocket?

Thanks,

Title: Re: Tuning villiers carb
Post by: Vreagh on July 22, 2021, 12:26:01 PM
Thanks for the "blurb"
Engine has two sprockets. Inside one is 17 teeth, I'm using that to drive a modified Lucas E3HM dynamo (there's no lighting coils). The outside sprocket is 22 teeth driving a 3 speed Albion 'box.
Title: Re: Tuning villiers carb
Post by: 33d6 on July 22, 2021, 03:12:48 PM
The separate Dynamo setup was the deluxe set up in the 1930’s. Bike rectifiers were in their infancy so effective battery charging from the lighting coils was still to come. Your type of setup for battery charging and thus steady lighting was basically the only practical way to go. Be cautious of using bicycle chain to drive the Dynamo. Proper timing chain lasts longer.
I’m curious about how the bike is on the road with a 22 tooth sprocket. The common Albion box of the period usually had a rather wide ratio spread with first gear so low you could pull a tank with it. With a 22 tooth sprocket I’d expect first to be more like first on a modern bike but top gear to be more like an overdrive and only usable on dead flat or down hill surfaces. How is it?
Title: Re: Tuning villiers carb
Post by: Vreagh on July 22, 2021, 06:46:18 PM
As I'm only on the final straight of a 3yr rebuild, the bike is not on the road yet. I bought it as a collection of tubes, forks, tank engine and gearbox so engine may not be off this bike, it has a peculiar sprocket arrangement. The two sprockets are on a common threaded sleeve, and allows adjustment in or out with the small sprocket acting as the locknut. As I live in hilly Cornwall, sounds as if there may be more problems ahead. The carb came from a Danarm 2 man chainsaw which also had this throttle control. Would this be similar to the bike unit mentioned in the "blurb"?
 
Title: Re: Tuning villiers carb
Post by: 33d6 on July 23, 2021, 12:34:48 AM
That is a standard Villiers throttle lever for use for use with a Villiers carb having the rod type mixture needle control.
Villiers also did a twin lever for the dual cable ‘de luxe’ needle control system but I find best of the lot is the postwar style of a seperate lever for each action. Trying to keep a smooth action on a dual lever is much more finicky than having seperate levers which you can adjust individually. My preference is the individual Villiers throttle lever as shown and a seperate LEFT hand needle control on the left side of the handle bars. In short, the common postwar setup as fitted to the postwar 6E and other E series engines up to the advent of the later S series carburettors.
Villiers Services should be able to supply the complete postwar set up.
As for your engine sprocket arrangement that is an absolutely stock Villiers arrangement. One of three they catalogued to suit the convenience of buyers. They were  just an engine manufacturer, they didn’t know what the buyer intended to do with their engine so catalogued various engine sprocket drive arrangements. That is one of them.
Title: Re: Tuning villiers carb
Post by: Rex on July 23, 2021, 08:22:50 AM
I have the same control lever on the Villiers mower I have as a garden ornament.
Title: Re: Tuning villiers carb
Post by: 33d6 on July 23, 2021, 09:58:30 AM
Yep, made by the gazillion.