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holley 650 double pumper tuning?
Just put a new holley 650 double pumper on my sbf. Reading the manual it says it could be jetted 3 to 4 too small. When I test drove the car it bogs when from a stand still to full throttle. Any info would be helpful.
5 Answers
- Me BrodLv 67 years agoFavorite Answer
A "Bog" is not from the jets. You have squirtter issues or accelerator plastic cam issues. Holley sells different size pump nozzles (squirters) and different profile plastic cam kits. Those cams are located and somewhat hidden on the throttle linkage. Nothing wrong with a Double Pumper on the street. People who insist on Vac secondaries do not know how to set-up a D.P. When you get a D.P. set perfect, it will throw you in the backseat from an idle. Go to Youtube. Search "Holley Tuning". It will show you how to change those accelerator pump cams.
- CBLv 77 years ago
Trying to tune an engine by 'ear' or seat of the pants is tough to do - too lean and you burn valve (and it may run like a scalded cat) to rich you carbon up the pistons and waste a lot of fuel. Jetting needs change based on intake restrictions and exhaust flow/back pressure. Your best bet would be to find a portable exhaust gas analyzer and figure it out a little more scientifically.
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- Anonymous7 years ago
@CB Big, big misconception in a four stroke engine, lean is NOT mean. You'll have more power running on the rich side.
-" too lean and you burn valve (and it may run like a scalded cat)"
