I'm trying to get my engine going good. Its a Cadillac 390 with a Weiand intake and three Stromberg WW carbs. Fuel pressure is set at 3psi and is as low as the regulator will allow (sotck mechanical fuel pump). Carbs were rebuilt at some point and not run til now, acclerator pumps look brand new. The center jet is 49 and the outer jets are 54. Screws are turned out approximately two turns. Linkage is straight but can be turned into progressive easily (and we've tried that and its still rich). What should I do and where should I start with adjusting these carbs to stop running so rich? I've got a decent idle and throttle response, but still too rich. Do I need all three jets the same? If so, what size? Just help me get this thing runnning well! My birthday is Wednesday and being able to drive my pickup again would be an awesome present from all of you, haha! This is the very last thing to do keeping me from driving again! Thanks!
i run two WW's both with 49 jets on a Stude 289 straight linkage and it is only a little bit rich. 2X your butterflys shutting off at idle, the blades may not be closing all the way.
Its not til Wednesday and I'll be 39, haha! But thanks!!! I want to get this thing going! I'm chomping at the bit!
No expert, but I would think that the outer carbs should be outfitted with smaller jets, not larger. But, what do I know.......... Keep at it, Kev! Oh, and happy birthday just a tad early!
Block off the end carbs and get it to run right with the center carb, then start to work on the end ones. Straight linkage should require all carbs to be jetted the same. On a 390 cube engine those carbs shouldn`t be too big. Bear in mind that even when it runs right with the single carb, it probably will be rich with all three, but you will at least have a starting point to work from. Drop a few jet sizes in all three at a time until you hit the right combo. You`ll need a shoebox full of jets!
Two turns on the idle screws is past wide open on the WW. Are you too rich at idle? Too rich at cruise? Too rich at power? Are all three carburetors the name number? What number? Idle mixture on the WW is normally from 1/2 to one turn. Jon.
The intake runners are separated. Running the center carb only totally leans out the outer cylinders. I'm too rich at idle and probably everywhere else too. I'm not really sure as I haven't been able to drive it except for one trip around the block. But according to your advice, I know the idle screws are turned out WAY too far. I'm not sure of the numbers on the carbs. I'm going to the shop now, I'll get the numbers, turn the screws in and report back. All three jets should be the same with straight linkage? Correct?
Yeah, I know. That should make a huge difference. I read on Jon's site that all three carbs should have the same size jets as well. Dustin has a jar full so I may be covered there as well. Me and Jeremy drove it around the block, but it cut out halfway round, probably too rich. Then the battery kept us from starting it again, lol. I got a new battery now so that's out of the way. I think with proper screw turning and proper jets we'll be good! maybe I'll get to really drive it by shop night!
Will be off the computer until Wednesday. Depending on what numbered carbs you have, I am GUESSING main jets should be 0.048~0.050 in all three. I would start with 0.050 and see what you have. Better to be a little too rich than too lean. And if they have been running rich, clean the spark plugs. Jon.
Dustin has my truck and will be bringing it back to me later on today. I bet if you ask really really nicely, he'll drop some jets off on the way back.
Dustin brought an assortment of Stromberg 97 jets but they are different. My Stromberg WW carb numbers are 7-106 which equal 1957 Buick 364 according to carbking Jon. And what a smart and helpful guy, by the way. Unfortunately, he doesn't sell just jets, full carb kits only which is a little out of my price range. I am currently trying to source proper jets.
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