Triumphrat

tjwood

Hi,
I'm going to treat my 1970 T100S to a new Amal Premier Concentric Mk1 carb but I'm not sure which one to get as the catalogue recommendations seem to vary. (The carb on the bike at the moment is 'suspect' as the bike takes ages to start despite new electrics, electronic ignition etc, then runs really rough at 1/4 throttle).

The Triumph spares book I've got says it needs a 626/25 - which has a number 4 slide, 170 main and 106 needle.
However, the Amal catalogue doesn't have an entry for a 1970 T100S, it only shows a 1968/1969 T100S and the carb for that is a 626/8, which has a number 4 slide, 180 main and 106 needle.
The Amal catalogue does have an entry for a 1970 T100/T100C and that shows the carb as being the 626/25 model (with air cleaner) but I don't know if my T100S would use the same carb.

I also want to run an air cleaner, just in case that alters anyones advice.

Any ideas which of the above would be a better starting point?

As I want to run an air filter so do you reckon I'd be better with a smaller cut-away slide? (The current 'bad' carb also has a number 4 slide so I was wondering if that's part of my problem).

Regards
Tony

DAVE M

Ring burlen fuels `(amal) for advice

they're in Salisbury

henryanthony

Tony,

Have you checked to find out if the pilot jet is clear. A clogged pilot jet will cause your bike to exhibit the symptoms you describe. It is responsible for starting, idling and running at small throttle opening.

You need a #78 drill bit and some carb cleaner to clean the pilot jet.

Henry

Mr.Pete

You can always file 1/16" off a #3 slide,to make it a #4.You can't un-file it,to make it less.
I'd start with a 3-1/2 slide.