Weber Carb adjustment

[bobhenry999]

Chaps,

I have a Weber 36 DCD fitted to my Coupe, and it`s running a bit too rich, but I don`t know which one of the numerous screws is the one to weaken the mixture, or the one to adjust the idle speed.
I have attached a photo if anyone can help.

Bob

[Richard Fridd]

Idle speed. Is there an adjusting screw which acts upon the throttle cable stop? Is it running rich throughout the rev range?

[John B]

Here is a link for a you tube video that explains the Weber 36 DCD......not watched it myself
but it may be useful.

https://www.youtube.com/watch?v=ECMYPE82gbo

[Jaydub]

The hexagon headed screw with the coil spring , at the base of the carb is the idle mixture adjustment screw. The idle speed screw will be where the throttle link is attached to the carb.
With the engine at operating temperature, and the idle speed approx 750 RPM, slowly turn in the mixture screw until the engine starts to slow, then back out 1/4 turn. That should set up the idle mixture, but if it still runs too rich it might require further investigation. It is always pointless tuning a carb, until you have correct points and plug gaps, valve clearances and ignition timing.
John

[bobhenry999]

Thanks chaps,

Will have a go at doing that adjustment John as soon as I get my exhaust from Germany which will be later this week.

I`m not sure if it`s rich at all speeds, but I got it out of the garage last week after 3 months, and let it run for half an hour on the drive, but when I went to start it this week it was reluctant to go, so I pulled the plugs and they were all filthy black.

Bob

[Jaydub]

Hi Bob,
I`m afraid letting the engine idle for half an hour and then inspecting the spark plugs is no indication of the mixture strength as the engine isn`t efficient at idle. Ideally you need a good run of 10-15 miles to clean out the combustion chambers etc, find a straight road where it`s safe to pull over, run a mile or so at 50 to 60mph, cut the ignition, close the throttle and coast to a halt in a layby or whatever and then inspect the plugs.
That should give you a better indication as it has run under load conditions. Hope this helps.
John.

[bobhenry999]

John,

Thanks for that advice about letting it idle.

I will get it out at the weekend, weather permitting and take it for a run and report back.

Incidentally, I have ordered an electronic ignition system that replaces the points and condensor from Per Tronix in the states, and will let you chaps know how it performs.

Bob