Well I am wondering If anyone can tell me how to adjust my carbs(HS6's?/64 b18)
I posted that I had gotten a bigger exhaust, and got only one response, to change the needle jets. That may very well be the case... but I've done some searching on SU's, and adjustment. What I've found is that the adjusting is done on the bottom of the carb on the spring loaded "bolt-thingy".
Which way do I turn it? (the artical said half turn incriments?)
thread it up into the carb(up), or out of the carb (out)
I want to richen the mixture and I'd rather not get into these carbs
Please some one give me some good solid advise

Yes, the big nut adjusts the mixture.

Did you do anything radical to the exhaust like change it from a single downpipe to dual downpipe manifold?

SU's can compensate a little by simply opening themselves higher if the motor demands more air/fuel mixture.

Hello Herk's122:

I want to give you a direct answer to your question but also encourage you - as others have - to get much more information about carbs, etc. and their proper setup and tune up before going so far down the rabbit hole that you cannot figure out which way was up.

The jet is pushed up into the carburetor by a series of levers as actuated by the manual choke. The nut with the spring backing sets the highest position that the jet will reach (vis-a-vis when the choke knob is pushed in completely.) The nut and threads are in the usual orientation so, facing the side of the nut, if you turn it to the right you will be raising the jet further into carb, therby leaning out the mixture. Turning the nut to the left pulls the jet out of the carb, making the mixture richer.

Turning the nut one flat at a time (1/6 turn) before each road test is the best way to go. I was told by a brilliant engineer who nearly landed a job at Toyota's F1 team that the best way to check the plugs is to take a drive on the highway with a nice broad shoulder. Get up to a good clip for a couple of miles then drop the engine into neutral and kill the ignition. Pull over and check the plugs for that beautiful coffee-brown color. He claims this is the truest test of the plugs' condition. Tooling around for even 1/2 mile in traffic can apparently change the color quite a bit, or so he claims.

Cheers,

Jeff Pucillo

I'd call it a cocoa tan. I drink my coffee MUCH darker than that!
--
George Downs Bartlesville, Heart of the USA!

Hello George:

Well said, and I should have added that in addition to the nice broad shoulder, make sure you have a nice broad at your shoulder.

Cheers,

Jeff Pucillo

I doubt she'd appreciate that description, but we've put up with each
other 44 years now.
--
George Downs Bartlesville, Heart of the USA!

Half turn increments of the adjusting nut are too extreme - one sixth turn at most between each test of a days driving. Fuel mixture adjustment should only be attempted after point gap, ignition timing, valve lash, and spark plug adjustments are set to factory spec.

Twiddling in the dark will likely cause less than desired results (guess how I know). If there isn't interest in comprehending the carburetors, then perhaps taking the car to someone familiar with its operation might prove productive. The Volvo green service manuals do have some excellent diagrams of SU carb operation. Highly recommended.

Joe M in WV

You mean: how do you ENrich your fuel mixture.

Anyway, unscrewing(out/down) will richen the carbs up. If you want an explanation of why/how, lemme know. Now, why do you think you need to ENrich the carbs anyway? Are you getting a hesitation when you first hit the gas when the car's warmed up fully? Have you checked your ignition timing?

richen & enrich are two words that mean pretty much the same thing.


PS: I found a head to photograph, now I just have to make a clean spot on my bench..... (harder than it sounds :-)