setting those carters
Thread Starter
Racer
Joined: Oct 2008
Posts: 366
Likes: 133
From: huntersville n c
setting those carters
I have the two carter four barrels on my 59. A rpm meter doesn't move enough to register any real change in engine speed. I set them by ear but they seem to be turned in (clockwise) a lot. Any suggestions to make sure my 283 runs well?
Larry Retired and living the hobby.
Larry Retired and living the hobby.
Pro
Joined: Sep 2008
Posts: 682
Likes: 0
From: Manteo NC
I have the two carter four barrels on my 59. A rpm meter doesn't move enough to register any real change in engine speed. I set them by ear but they seem to be turned in (clockwise) a lot. Any suggestions to make sure my 283 runs well?
Larry Retired and living the hobby.
Larry Retired and living the hobby.
Burning Brakes
Joined: Oct 2004
Posts: 953
Likes: 27
If you are talking about idle mixture adjustment; my experience has been that 3/4 to 1+1/4 turn out is where most seem to run best.
Of course carb float level(s), ignition tune, camshaft, valve lash, etc. all may affect these adjustments. The idle air rate (idle speed screw) should me set equally for both also.
As stated above, a vacuum gage also works well.
Of course carb float level(s), ignition tune, camshaft, valve lash, etc. all may affect these adjustments. The idle air rate (idle speed screw) should me set equally for both also.
As stated above, a vacuum gage also works well.
Melting Slicks
Joined: Mar 2001
Posts: 2,372
Likes: 51
From: New Milford CT
Start with all four idle Mixture screws out 1 full turn each. Then adjust the idle Speed screws to your chosen idle level. I like about 900 rpm. Then go back and tweak the mixture screws. Try a 1/4 turn in and out each pair of Mixture screws at a time and listen and feel what your engine likes.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
These old carbs are finicky to adjust but run like the dickens when properly set. Sometimes you just have to find the sweet spot with the idle mixture screws....I have had to back them out sometimes (counter-clockwise) until the engine stumbles then start working them back in. A vacuum gauge is crucial. Anyway I have some old manuals on tuning/repairing these carbs that I will email you if you PM me with your email address.
Don't be surprised if the mixture screws are only 1/4 turn out or so...not unusual...
Don't be surprised if the mixture screws are only 1/4 turn out or so...not unusual...
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
On my 2x4 C1's, I always added a Paragon #755 vacuum fitting to the base of the rear carb, replacing the stock plug, for a convenient spot to attach a vacuum gauge for adjusting the idle mixture screws.
The 2-piece fitting simplifies installing it - you leave the threaded nipple off during the install so you don't have to raise the carb off the manifold for swing clearance, then screw in the nipple.
The Dave Zuberer file below shows it in detail.
The 2-piece fitting simplifies installing it - you leave the threaded nipple off during the install so you don't have to raise the carb off the manifold for swing clearance, then screw in the nipple.
The Dave Zuberer file below shows it in detail.
Le Mans Master
Joined: Feb 2008
Posts: 5,215
Likes: 447
From: NJ Hockey beer league
Larry, you did not mention if your Carbs have been serviced recently or not but in addition to all of the above, I would remove all the idle mixture screws and spray some gumout in each of the mixture holes, followed by some compressed air. This will assure that one or more of the idle circuits is not partially plugged. Reinstall the screws about 1 1/2 turns from bottom and proceed as above with the vaccum guage and tach hooked up. Pilot Dan
Pilot Dan
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