TFS Trials with Trials Parkinson barrel - Amal Carb Settings

[jhalfpen]

Hi
I have a '65 TFS trials fitted with a trials Parkinson barrel and head fitted with an Amal 626 Mk.1 concentric. Does anyone know the correct jetting for this carb. on the parkinson barrel please?
John

[John Wakefield]

John
Greeves never fitted the Parkinson barrel & head to any model. The TFS had a Villiers S25/6 carb.
As a starting point, the Amal 626 was fitted to the THS and TGS with the following settings. I would think they would be about right also for the Parkinson set up.
Main Jet: 140
Pilot jet: 25
Jet taper: .106
Groove: 2
Throttle: 2 1/2

[350biker]

Thanks for pre-empting a question I was going to post. Do you think these settings will work on a 32A trials motor? I am having trouble setting a 626 up. It came off a 32A engine being used in a Pre 65 (!) |James for trials. Works fine at trials speed but out on the road it is very rich, four stroking and detonating.

[John Wakefield]

Yes should be OK as jetting is fairly consistent to carb size, main jet & pilot jet should be OK but you may need to alter needle up or down a notch. The iron barrelled 32A should have an S25 Villiers Carb which is a simple carb and gives good results & was designed for the engine. The Amal carb comes in 2 stroke and 4 stoke form and you must have the correct type. (Rob can put you right on that)

[jhalfpen]

Thanks John - I'll give it a try. Hoping to get it set up correctly to take to Mons in November

[350biker]

Thanks John W. The S25 off my motor was badly worn and rebuilt as best they could by VS. So jumped at the chance of a Concentric when it was offered to me. Will try the jets and settings as given above.