Latest topics
» 1925 350cc fanny b
Today at 9:42 am by keith.hodgenia

» Items wanted
Today at 8:24 am by nick17

» Wheel bearings anyone?
Today at 7:12 am by piston 197

» Cruiser 80 speedo
Today at 12:33 am by intrudin

» Spalding Show
Yesterday at 10:24 pm by kerabo

» Owners Club Badge
Yesterday at 9:52 pm by zorteus

» Local meetings
Yesterday at 5:54 pm by nick17

» Plover 78 Front footrest
Sun Dec 09, 2018 8:01 pm by Gyrocopter

» wheel bearings knock through spindle
Sun Dec 09, 2018 3:52 pm by piston 197


6e carburettor

Go down

6e carburettor

Post  david swerdlow on Wed Nov 14, 2018 7:16 pm

Thinking of putting a more user friendly carb on my 6e bike at present its running an  s25 but a friend mentioned a Mikuni or an Amal  what say you folks out there ?

david swerdlow

Posts : 27
Join date : 2016-08-24

Back to top Go down

carburettor

Post  piston 197 on Wed Nov 14, 2018 8:06 pm

Normally the 6E would be running the earlier brass bodied carburettor rather than the S25, but the S25 is a simple instrument and set up correctly should give no problems.
FB fitted 276 pre monobloc carbs to their competition bikes and thes run a treat, i have tried Amal monobloc and concentric 626 carbs on villiers 197cc and they are no better than the Villiers abd cause all sorts of other problems, personally i have never ran a Mikuni on a Villiers, but a 2 stroke one from a 175/185 Jap trail bike might be a good place to start ?
JH
avatar
piston 197
Moderator

Posts : 4158
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

6e carburettor

Post  david swerdlow on Sat Nov 17, 2018 3:59 pm

Many thanks for that advice , maybe I will spend a bit more time sorting it out , yours david

david swerdlow

Posts : 27
Join date : 2016-08-24

Back to top Go down

Carburettor

Post  kerabo on Sat Nov 17, 2018 4:08 pm

What problem do you have David

Ken
avatar
kerabo

Posts : 2519
Join date : 2008-02-11
Age : 68
Location : Falcon 87..1936 Cruiser 39. Falcon 81 Green Lane bitsa. Sunbeam S8. Honda Deuville.

Back to top Go down

6e carb

Post  david swerdlow on Sun Nov 18, 2018 5:16 pm

Just general running and tick over .

david swerdlow

Posts : 27
Join date : 2016-08-24

Back to top Go down

Tick over

Post  piston 197 on Sun Nov 18, 2018 5:22 pm

There is normally no provision for tickover on a S25 carburettor, any tickover should be friction controlled from the twist grip, some late series carburettors had an extra boss next to the mixture screw that could be tapped out to accomodate a taper ended screw to lift the slide, this was a fitment on some Villiers powered cars/three wheelers and can be adapted for motorcycles.
Tick over can also be set from the cable adjuster, but this tends to pull and increase revs when the bars are turned

Most important setting on an S25 carburettor for general running is the length of needle protruding from below the slide bottom, on an 8E this should be 1.95" althogh wear might mean this needs to be increased slightly ?
JH
avatar
piston 197
Moderator

Posts : 4158
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

Poor running

Post  kerabo on Sun Nov 18, 2018 5:24 pm

David

Check you have the correct needle and that the float height is correct.

I bought a carb body with the drilling for and idle screw and it works very well.

They are normally very forgiving.

Is the S25 a good fit on the stub?

Ken
avatar
kerabo

Posts : 2519
Join date : 2008-02-11
Age : 68
Location : Falcon 87..1936 Cruiser 39. Falcon 81 Green Lane bitsa. Sunbeam S8. Honda Deuville.

Back to top Go down

Re: 6e carburettor

Post  FBKev on Sun Nov 18, 2018 6:41 pm

The James owners manual I got with the Captain (my one is a 59 with a S25/2 carb) which was for a 9e (same carb I believe) model, not the 10e that I have,  does say that tick over is set by the adjuster & locknut on top of the carb. I will try to scan the relevant part, if that is not successful I will type it out verbatim. After reading that, that is how I set for the James and it has been good so far, of course after making sure the timing, points gap, plug gap was correct and the engine at operating temperature.
Kev.


Last edited by FBKev on Sun Nov 18, 2018 7:03 pm; edited 2 times in total
avatar
FBKev

Posts : 99
Join date : 2018-06-17
Age : 58
Location : SE Kent

Back to top Go down

tickover

Post  piston 197 on Sun Nov 18, 2018 6:49 pm



As i said previously there is normally no provision for Tickover on a S25 carb, which will be why the manual above makes  reference to adjusting the cable if a tickover is required
I did say it can be set by
a) friction control on the twist grip and not fully closing it
b) adjuster on cable at top of carb, but this usually causes the bike to rev when the handlebars are turned and the cable pulled
c) Adjuster screw inserted into the boss next to the mixture screw ( this only appears on very late model S25 carbs numbered S25/7)


Last edited by piston 197 on Sun Nov 18, 2018 8:32 pm; edited 1 time in total
avatar
piston 197
Moderator

Posts : 4158
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

Re: 6e carburettor

Post  FBKev on Sun Nov 18, 2018 7:00 pm

Sorry about that, I only meant to post but for some reason I appear to have quoted myself on JH's post (no idea how I managed that)
Kev.
avatar
FBKev

Posts : 99
Join date : 2018-06-17
Age : 58
Location : SE Kent

Back to top Go down

Quote edited

Post  piston 197 on Sun Nov 18, 2018 8:33 pm

Kev as Toyah Wilcox said " ith a mythtery"

Quote removed

JH
avatar
piston 197
Moderator

Posts : 4158
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

6e carb

Post  david swerdlow on Mon Nov 19, 2018 12:15 pm

No tick over adjustment ! oh dear so will adjust as per instructions , what a great bunch you are , another project has wormed it's way in so will be mothballing it for a few months , with many thanks david .

david swerdlow

Posts : 27
Join date : 2016-08-24

Back to top Go down

Re: 6e carburettor

Post  John Wakefield on Tue Nov 20, 2018 1:18 pm

piston 197 wrote:

As i said previously there is normally no provision for Tickover on a S25 carb, which will be why the manual above makes  reference to adjusting the cable if a tickover is required
I did say it can be set by
a) friction control on the twist grip and not fully closing it
b) adjuster on cable at top of carb, but this usually causes the bike to rev when the handlebars are turned and the cable pulled
c) Adjuster screw inserted into the boss next to the mixture screw ( this only appears on very late model S25 carbs numbered S25/7)

The S25 can be modified to have a throttle screw, needs a hole drilling and tapping and a screw and spring obtained or made. I think a mixture screw may suffice. The indent is there on the casting but not machined on all carbs. the S25/6 had the throttle screw it was used on the Bind Minicar

John Wakefield

Posts : 87
Join date : 2017-08-31

Back to top Go down

Idle screw

Post  kerabo on Tue Nov 20, 2018 1:40 pm

Not all have the blank drilling point. I tend to buy a them when I come across them. They are 2BA from memory. The slide has a cut out but that can be ground or filed into it.
It does make a nice conversion

Ken
avatar
kerabo

Posts : 2519
Join date : 2008-02-11
Age : 68
Location : Falcon 87..1936 Cruiser 39. Falcon 81 Green Lane bitsa. Sunbeam S8. Honda Deuville.

Back to top Go down

indent for tickover screw

Post  piston 197 on Tue Nov 20, 2018 1:41 pm

The indent is there on the slide, but only the late s25/6 and s27/7 carb bodies have the boss to tap out
if your carb is earlier you will need to change to a later body
JH
avatar
piston 197
Moderator

Posts : 4158
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

Re: 6e carburettor

Post  FBKev on Tue Nov 20, 2018 4:32 pm

Not wishing to hijack your thread David but while we are talking carb and throttle cable adjustment on the pressed steel top yoke, there are two holes that on both the Captain and Falcon the clutch & throttle cables have been routed through is this correct? as on the twistgrip side it does tend to stretch the cable and increase revs a JH said, also a bit of a tortuous route for either.
Kev.
avatar
FBKev

Posts : 99
Join date : 2018-06-17
Age : 58
Location : SE Kent

Back to top Go down

Throttle cable pull

Post  piston 197 on Tue Nov 20, 2018 4:41 pm

To minimise this run the cable along the side of the frame tube and tape it firmly in 2 places once as it just bends down to the carb and once just behind the headstock.. make sure it has sufficient length so that on r/hand lock it is not pulling the cable.
You might have to experiment with this and best to do so with the tank off, remove the airfilter and place a cable tie trough the back of the carb and rest it under the throttle slide, if you turn the bars and the cable dips, then it is pulling the slide up.
Not rocket science, just experience ! and a tip worth remembering
JH
avatar
piston 197
Moderator

Posts : 4158
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

Re: 6e carburettor

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum