Bike Carb Vacuum Ports.

[Guest streetsy]

Hello all, I'm looking for advice on vacuum take offs for both dizzy and servo when using bike carbs. I'm currently making my manifold to take the bike carbs for my pinto engined Exmo and i'm unsure whether to tap a port into no 1 cylinder inlet for the distributor and a port into no 4 for the servo, or, tap into all four inlets and go to a sort of balance tube with one end for servo and one end for distributor. See (very) crude sketch below. Has anyone had issues good or bad with either of these ways of vacuum take off.

Inlet1.bmp

[richardm6994]

or, tap into all four inlets and go to a sort of balance tube with one end for servo and one end for distributor. See (very) crude sketch below. Has anyone had issues good or bad with either of these ways of vacuum take off.

 

That's the best solution, especially for the dizzy as it stops the advance mechanism from pulsing at low rpm (I had this after taking advance vac from cylinder 1 only).

[Guest streetsy]

I thought that would be the case especially as it has a fast road cam so idle is a bit lumpy at the best of times.

[maccavvy]

balance bar is the better idea.. plus my servo take off is on number 4

[tractor]

best thing you can do is get a bestek ignition so you do away with vacuum advance so just servo to number 4 plus the bestek ignition will give more power to complement your fast cam and bike carbs

[Guest MarkB]

Or utilise the club discounts and get a accuspark stand alone system

[Guest mower man]

I have a brand new non vac bosch type distrib for a 2.0 Pinto ,never been fitted ,simple 2 wire setup as used by many grass trackers yours for 100£ ,pm me you can't be a long way away I'm in Worksop may even chuck a bn coil in and price may be flexible mower man +full set of 8mm leads [all are over length so you can cut to make custom fit] brand new !!!

Edited September 17, 2013 by mower man