Running rich 1956 16ms

[Taid]

Got the carb off again ..

................

Where is your air screw set?

Does your choke slide fully retract? can you raise it further by pulling up on the outer?

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Hi, M.D

Pilot air screw almost exactly 1.5 turns out ..

Choke slide does fully retract ..

Do you get any response when adjusting the pilot jet? It's primarily the pilot jet (and to a lesser extent the slide cutaway) which supplies fuel at tickover and up to maybe half throttle after which the main jet becomes involved. The pilot screw adjusts the amount of air being supplied, not the fuel. If the engine doesn't show much response to pilot screw adjustment it's likely that the very narrow pilot drillings are obstructed. The 'normal' setting for the pilot screw is about one and a half turns 'out'.

Check, as best you can, the drillings 7, 8 and 9 by forcing aerosol WD40 or brake or carb cleaner through........

Hi S.

It is quite sensitive to the air adjust screw. Any movement affects revs virtually immediately ..

looked for drillings 7 & 8 in the past .. just identified them .. previously thought they were blemishes in casting ..

is thebest way to blow 7 & 8 via drilling 9? can't really see how to get at them otherwise .. have to wait a few days (till first jab has had time to start its magic) to get brake/carb cleaner .. not too fond of WD40 .. tends to leave a sticky residue ..

PS I wonder how accurate that cutaway drawing is .. with my needle in (what I believe is) the centre notch it protrudes slightly above the throttle slide whereas the drawing shows it virtually level .. ?

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Thank you both .. Taid

[dave16mct Profile]

Check the needle. For a 376 it should be a 'C' and 95mm long.
Dave.

[Taid]

Check the needle. For a 376 it should be a 'C' and 95mm long.
Dave.

Not actually checked length, but is a (brand new 'C')

[dave16mct Profile]

Check the length of that needle. It could be from a different carb altogether.
Dave.

[Taid]

Check the length of that needle. It could be from a different carb altogether.
Dave.

I think my
edit and your post crossed over .. It is a C .. my finger trouble and not reading what I have typed .. but I will measure it ..

[Taid]

Check the needle. For a 376 it should be a 'C' and 95mm long.
Dave.

Confirm .. it and the original are both marked 'C' .. but not 95mm.. both are 97mm long, or 93mm from the top ring .. the new one was supplied by Burlen in Octobertime last year ..

[Mick D Profile]

is thebest way to blow 7 & 8 via drilling 9? can't really see how to get at them otherwise

Hi

Yes, but in your case it would be very unlikely for the pilot or bypass galleries to be blocked, (blocked would result in poor / no slow running, poor / no pick up from slow).

Have you replaced the float valve needle?

Regards Mick

[Taid]

........

Have you replaced the float valve needle?

Yes, M.D .. when I fitted all new jets and the needle ..


I think I will shelve work for the moment, until I can take it out for a long(ish) run and look at the plug afterwards to see how it looks then.

Thanks to all who have given me guidance ..