650 DP question
Thread Starter
Moderator
Joined: Jun 1999
Posts: 7,117
Likes: 51
From: Dove Mountain Arizona
650 DP question
I know DP carbs are inherently rich running carbs but is there a way to easily 'lean' out the primary side so my plugs won't be dripping in oil? Just changed the plugs (a yearly event) and 1,3,7 and 8 are brown/black. 3 and 5 are sooted and dripping wet. 4 and 6 are black also. It's a Holly. Thanks...
if you have oil on the plugs you could have a valve seal or ring issue not carb as mentioned above.
Thread Starter
Moderator
Joined: Jun 1999
Posts: 7,117
Likes: 51
From: Dove Mountain Arizona
I meant wet as in fuel. I have a 355 with 64cc Sportsman II heads and a Weiand Stealth intake. Isky 270/280 Megacam hyd. Ignition is a points replacement electronic type, the brand escapes me right now. 
Racer
Joined: Apr 2006
Posts: 477
Likes: 43
From: Millbrae California
In my opinion a holley double pumper is not THAT rich with the factory calibration, your problem may be from a bad power valve, high fuel pressure, float level set too high or if the bowl screws are not tight the fuel can leak between the metering block passages at the gasket. The newer non-stick metering block gaskets do not seal as well as the older (black) gaskets did so it is advisable to tighten your bowl screws every few thousand miles.
I hope this helps Henry @ olescarb
I hope this helps Henry @ olescarb
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
If as mentioned above, if you have no internal leaks or bad parts, and proper transfer slot adjustment, you can really clean up the idle by reducing the size of the idle flow restrictors. Particularly if your mixture screws don't respond as they should.
Below in the middle pic (arrow) is their location. You could start with a .010 wire and go from there.
Below in the middle pic (arrow) is their location. You could start with a .010 wire and go from there.
