Rob's WD16H and Big4 Forum

One of first 500 of contract C14498 with leg shields

Rob's WD16H and Big4 Forum
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carburettor adjustment

when using mit 16h in daily urban traffic it seems as if the engine is running too fat. the spark plug is deep black and after a while the engine begins to run quite bad.

there are two screws at the carb. the one is responsible for the minimum height of the slide, the other one is surely the idle mixture screw. as i have no further info about the amal 276 i would benefit from your experience regarding how many turns the idle mixture screw should be turned.
does it regulate air or fuel?
are there any links dealing with the details of the amal 276?

any input would be highly aprreciated.

Re: carburettor adjustment

That screw controls the air for idling. Screw it in gently then back it out approx 1 1/2 turns.

Have you downloaded the Maintenance and Instruction Manual from the front page of this website? It is absolutely essential reading for the care of these machines

Re: carburettor adjustment

thanks for the reply. i have downloaded it but simply not found the relevant info at first glance (seems to be a phenomenon of the digital area: lack of patience ..).
after browsing through the doc 2nd time i have found info on page 51.
@rob: thanks a lot for the info about the amal carb.

Re: carburettor adjustment

Mine ran rich whatever I did, worse when stationary. Fixed it with a new plastic float and matching needle.

Re: carburettor adjustment

thanks for your feedback. meanwhile i have readjusted the carb according to the data provided by rob. now it runs quite well but does not have a stable idle. when stopping at red lights i have to twist the throttle to keep the eninge running.

Re: carburettor adjustment

Who needs a tickover? Norton owners have a long tradition of blipping the throttle, whether it's to warm up a Manx or to beat a Gold Star away from the lights on a 16H :smile: