650 double pump
#1
Senior Member
RACING JUNKIE
Thread Starter
Join Date: Jan 2006
Location: EastWenatchee,WA
Posts: 887
650 double pump
as some of you know, got a new carb tried it once runs excellent out of hole and mid,top end seemed lean , thought I had 76 in rear, there is no powervalve in rear, but had 78's in there Do you all think a 82 is to big in rear or will that work? have 72 in front with a 6.5 powervalve
#3
Senior Member
RACING JUNKIE
Join Date: May 2006
Posts: 2,044
I know the rule of thumb is ten but I've never went that far, always seemed to rich for my combo, aren't you bracket racing this thing?
If so your gonna want it on the lean side anyway, but not too lean. you'll have to read your plugs to determine that.
A leaner mixture wont pick up ( e.t. ) as much when it cools off later in the night. you'll run much more consistent that way.
Goodluck, Charles
If so your gonna want it on the lean side anyway, but not too lean. you'll have to read your plugs to determine that.
A leaner mixture wont pick up ( e.t. ) as much when it cools off later in the night. you'll run much more consistent that way.
Goodluck, Charles
#4
This is an example of mine, spib, I have a 650 DP, with no power valves, 50 cc pumps front and rear, and it's jetted with 76 front and 82 rear, ran this carb on most every streeter I've ever had. It's just been rebuilt and ready to go on the next one.
#5
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RACING JUNKIE
Join Date: May 2006
Posts: 2,044
Here's an example of the set up I was running on a holley 750 double pumper footbraking a mild bbc 468 bracket racer.
No power vavle,
82 square,
50 cc front acc pump
32 squirters front and rear
Proform contoured venturi center section
super crsip throttle response and ran dead on consistent all night.
No power vavle,
82 square,
50 cc front acc pump
32 squirters front and rear
Proform contoured venturi center section
super crsip throttle response and ran dead on consistent all night.