SPITTING CARB - 914-6 all stock, **** Triangle of Items **** Options

[ctc911ctc]

1970 - 914-6 All stock

Got the car off the rack after a 1 year clean up documented here:

http://www.914world.com/bbs2/index.php?sho...3371&st=100

- tightened the lugs, check one more time for leaks.......

Car started first try, backed out of the driveway and went around the block

Drive strong.....very strong......

#2 cyl-carb is still 'spitting' definitely not backfiring. Chasing this through my trusty guide:

https://www.performanceoriented.com/special-procedures-1

See "notes" section

Seems that when I performed the Lean Best Idle procedure #2 failed during the procedure......the diagnosis within the document states that either the path in that carb #2 is blocked or the jet is the wrong size - my bet is a clog......though the carbs were very clean when I got the car.

There is a little noise from the right side, that in a 914-2L 4Cyl would be considered quiet, my hope is that it is not valve noise and may be exhaust leaking......did I tighten the heater manifold small nuts????? dry.gif

Carb advice sought from those that have chased a SPITTING Carb

[Superhawk996]

I’ll go back and read all of Performance Oriented’s instructions but when tuning I’ve always started with all air correction screws fully closed. (Edit:) I agree his directions aren’t explicitly clear to start with all air corrections screws initially closed and then to only proceed to no more than 3 turns open. Nor does it indicate that one screw ought to remain fully closed. . In the defense of those directions, I think there is some assumption built in that these instructions assume some prior familiarity with Weber carb tuning and that you followed his initial installation instructions.

(Edit 2) he does call out that the air correction scews are to start from closed position in the initial installation instructions.


Which ever bore is highest flow with the snail sets the bar for the other two throttle bores. The air correction screws are then opened on the other two lower flow bore’s to bring all three up to the same snail flow level. One screw (that was highest initial flow) should remain untouched and fully closed. The air correction screws are allowing air to bypass the closed throttle plate - affecting how much vacuum is pulling on the idle jets.

I’ll repeat that: The more you open the air correction screws, the more you degrade the vacuum signal on the idle circuit.

I would not recommend starting with all three air correction screws open 1.5 turns. That is just letting in excess unmetered air into at least one bore needlessly.

Even at 1.5 turns you’re letting more air into all three bores than need be for no reason and degrading your idle signal to all three throttle bores.

Someone can call me out but that is the way I do it. I think this is the recommendation in the Weber tuning manual as well. As stated, I’ll go back and read the instructions that you referenced and will provide you with some relevant pics and links.