Showing Visitor Messages 1 to 4 of 4
-
Hello
I have an original ...15.00 scott
-
11-03-2009 01:54 PM
Kenth
Hi!
Is the carb going back to the original engine?
Stock jetting for #7042264 is jets stamped #74, primary rods stamped #47, secondary rods #7045923 stamped CR with 5/8 turn preload on airvalve spring. #7037305 power piston spring.
Float setting 3/8".
Pump rod location, inner.
Fast Idle (bench) 2-turns, on high step.
Fast Idle Rpm, 1500-N 2:nd step hot engine, choke off.
Vacuum break .195".
If your engine is modified with a hotter than standard camshaft, the carbs idle circuit WILL have to be modified/adjusted to the new lower vacuum signal the hotter cam provides.
After setting the idle mixture needles for best lean idle, approximately 2.5 turns out from lightly seated, you may do the "tip-in" test. Slowly close the choke-blade and note the first change in rpm before the engine chokes. If you´re close there would be no change before the engine chokes, if rpm drops idle circuit is too rich (rarely happens), if rpm increase the idle circuit may be lean.
Then set the fast idle cam on high step, use the fast idle screw to set 2200rpm´s, do the "tip-in" again, here you will notice a 50-150 rpm increase wich indicates a close to proper cruise mixture.
Rpm decrease here indicates a too rich mixture, again rarely happens with original jetting, more than 200 rpm increase indicates a too lean mixture and smaller/richer primary rods will be needed.
Hope this helps some......
Greetings,
Kent
-
Hi!
A member on the board suggested I send my question to you regarding quadrajets:
I just rebuilt a 72 q-jet 7042264 using Cliffs book and rebuild kit. What I cant seem to find is the data table for stock settings on this carb. Anyone know of a source?
BTW...I have 48 primary metering rods, CS secondarys, 74 jets, N hanger, not sure which spring to use in the power piston or what the float level is supposed to be (I started with 1/4").
Want to get this thing as close as I can before I try it out on the engine. Cliff said that a stock rebuild would be good start for my altitude as this was a lean Califonia carb.
Thanks!
-
Tjena Kenth, mycket folk blir det den 19/9. regards from Svante 400