any holes in the throttle blades?may have to enlarge if you have them and make some if you don't.or


go efi.

No holes, in fact the transfer slots are barely visible under the blades. I did however just figure out that whoever assembled the carb last used a 2 circuit metering block gasket instead of a 3.

As it turns out I have 3 circuit main bodies however the carburetors have already been converted to 2 circuit, hence the 2 circuit gaskets. Perhaps I'm closer than I think I am and the timing will actually get me over the hump.

the timing curve is very critical with carb adjustments. I had my 540's at Nickerson performance and Dean did the dyno set up on both motors, so glad i did this. he spent a lot of time on timing curve with my Daytona Sensors ignitions and more carb changes between pulls til it was where he liked the engine response. I ended up with 12* start retard 20* initial with max at 38 dist locked idle at 750. he got my carbs close to the engine specs i gave him before i brought the motors but had to do more metering block work between pulls. in the end both motors idle was very smooth and stayed consistent even with slight load as if it were in gear.

JS are you naturally aspirated? How much idle stabilization are you using? Is 38 the trigger timing or the total timing?

If I understand the CD-1 correctly the max retard you can do from trigger timing is 22* (to prevent cross firing). If your trigger timing is 38* then your start-up timing can only be 16*. Effectively you only have 4* start retard? Please correct me if I don't have this correct.

Went and looked at my datalogs.

my idle map is 16* base. I add 20* of timing when the idle falls below 700rpm with stabilization. I looked at the logs during cranking, while the start retard option is set to 10*, its showing 13.6 degrees while cranking. So, if it was actually pulling 10* during cranking, it should show 6*, but its not.

Mild, what is your trigger timing? Also, can you tell how much timing is being added in order to maintain 700 RPM?

Why do you want your idle at 1000 rpm if your in gear speed it 700? This is in reference to the opening idle screws comment. Doesn't the CD-1 have a timing map in it and control timing based on RPM like efi would without TPS input? Also, what does the size of cam have to do with idle timing and retarding. Excuse my ignorance, I've just play with my EFI timing idle map to get it to do what I want in gear and have been able to maintain about a 50rpm difference and did the best with running my initial timing at about 9 and just have it increase at about 1300 rpm to a normal profile. I initially had it around 22 and found it impossible to get it to behave in and out of gear. When it goes in gear the comp bumps about 8-10 degrees to maintain speed.