carb help, Holley dbl pump. - Page 2

Keith 944 · 07-29-2012, 01:35 PM

ok, i found whats up, left bowls full last night. today front is empty. now i know where to look. more later....

Ed Wright · 07-29-2012, 02:18 PM

Quote:

Originally Posted by Keith 944

ok, i found whats up, left bowls full last night. today front is empty. now i know where to look. more later....

If the front throttle blades don't get wet when it sits the primary power valve gasket is leaking.

jmarkaudio · 07-29-2012, 03:35 PM

I've seen some less than stellar PV gaskets lately, the best ones out there now are some red ones from Quick Fuel. It's the same material they use on their new float bowl and metering block gasket. There used to be some really good blue teflon coated ones, I wish I knew where they came from.

NORMAN BARNARD · 07-29-2012, 06:29 PM

Jmarkaudio......try braswell carburetors in tucson, az. Part number for teflon coated p/v gasket is 082501..........norm

Keith 944 · 07-30-2012, 04:33 PM

looks like I'm going to have to remove it and look more. i took the metering plate off, changed pv. gasket, metering block gasket. same leak, (takes about 10 min to see a measurable diff). took apart again, grinded pv plug, flipped gasket, tried again. same leak. seems to be low on the throttle blade area....

BlueOval Ralph · 07-30-2012, 05:34 PM

Put new bowl gasket, float bowl gasket and bowl screw gaskets torque bowl screws to 35 inch pound

NORMAN BARNARD · 07-30-2012, 06:42 PM

Venturi's warped or metering block, quick check, move sec. Metering block(assumed it's not leaking) to the end having problem redo fill bowl and recheck for leak. If no leak it's the venturi.......mill flat, but recheck for clearance of p/v and stud boss in the area. I
ve had some come thru with "excessive" dichromate/bright zinc that would not let the plate gasket seal to the venturi and it dribbled out the off idle transfer slot in the base plate.

One more item to check, the cast in dowel pins in the metering block maybe bottoming out in their associated holes, place metering block minus gasket against venturi and check end-end and side-side for any "rocking". If there is, drill the holes or grind down the pins to fit the hole depth......

Keith 944 · 07-30-2012, 08:09 PM

uggggh. i switched the metering blocks front to rear, rear to front. same leakdown. must be in main body, now what?

Steve Hayward · 07-30-2012, 08:20 PM

Quote:

Originally Posted by Keith 944

uggggh. i switched the metering blocks front to rear, rear to front. same leakdown. must be in main body, now what?

I have not read all the posts..... but if the front throttle blades are too far open, the carb will be sifoned through the transfer slot when the engine shuts off and cools down............

NORMAN BARNARD · 07-30-2012, 08:25 PM

Keith, find some one with a bridgeport milling machine that can true of the venturi gasket surfaces....any machine shop should be able to do it. When complete recheck metering block pin holes for correct depth.....good luck.

07-29-2012, 01:35 PM	#11
Keith 944 VIP Member Join Date: Feb 2006 Location: Dela-where? Posts: 2,125 Likes: 1,015 Liked 1,661 Times in 526 Posts	Re: carb help, Holley dbl pump. ok, i found whats up, left bowls full last night. today front is empty. now i know where to look. more later.... __________________ KEITH MAYERS 2 X somebody many X nobody

07-29-2012, 03:35 PM	#13
jmarkaudio Junior Member Join Date: Apr 2008 Posts: 83 Likes: 0 Liked 0 Times in 0 Posts	Re: carb help, Holley dbl pump. I've seen some less than stellar PV gaskets lately, the best ones out there now are some red ones from Quick Fuel. It's the same material they use on their new float bowl and metering block gasket. There used to be some really good blue teflon coated ones, I wish I knew where they came from.

07-29-2012, 06:29 PM	#14
NORMAN BARNARD Member Join Date: Mar 2006 Location: EL PASO, TEXAS Posts: 156 Likes: 0 Liked 2 Times in 2 Posts	Re: carb help, Holley dbl pump. Jmarkaudio......try braswell carburetors in tucson, az. Part number for teflon coated p/v gasket is 082501..........norm

07-30-2012, 04:33 PM	#15
Keith 944 VIP Member Join Date: Feb 2006 Location: Dela-where? Posts: 2,125 Likes: 1,015 Liked 1,661 Times in 526 Posts	Re: carb help, Holley dbl pump. looks like I'm going to have to remove it and look more. i took the metering plate off, changed pv. gasket, metering block gasket. same leak, (takes about 10 min to see a measurable diff). took apart again, grinded pv plug, flipped gasket, tried again. same leak. seems to be low on the throttle blade area.... __________________ KEITH MAYERS 2 X somebody many X nobody

07-30-2012, 05:34 PM	#16
BlueOval Ralph Banned Join Date: Feb 2008 Posts: 852 Likes: 0 Liked 0 Times in 0 Posts	Re: carb help, Holley dbl pump. Put new bowl gasket, float bowl gasket and bowl screw gaskets torque bowl screws to 35 inch pound

07-30-2012, 06:42 PM	#17
NORMAN BARNARD Member Join Date: Mar 2006 Location: EL PASO, TEXAS Posts: 156 Likes: 0 Liked 2 Times in 2 Posts	Re: carb help, Holley dbl pump. Venturi's warped or metering block, quick check, move sec. Metering block(assumed it's not leaking) to the end having problem redo fill bowl and recheck for leak. If no leak it's the venturi.......mill flat, but recheck for clearance of p/v and stud boss in the area. I ve had some come thru with "excessive" dichromate/bright zinc that would not let the plate gasket seal to the venturi and it dribbled out the off idle transfer slot in the base plate. One more item to check, the cast in dowel pins in the metering block maybe bottoming out in their associated holes, place metering block minus gasket against venturi and check end-end and side-side for any "rocking". If there is, drill the holes or grind down the pins to fit the hole depth......

07-30-2012, 08:09 PM	#18
Keith 944 VIP Member Join Date: Feb 2006 Location: Dela-where? Posts: 2,125 Likes: 1,015 Liked 1,661 Times in 526 Posts	Re: carb help, Holley dbl pump. uggggh. i switched the metering blocks front to rear, rear to front. same leakdown. must be in main body, now what? __________________ KEITH MAYERS 2 X somebody many X nobody

07-30-2012, 08:25 PM	#20
NORMAN BARNARD Member Join Date: Mar 2006 Location: EL PASO, TEXAS Posts: 156 Likes: 0 Liked 2 Times in 2 Posts	Re: carb help, Holley dbl pump. Keith, find some one with a bridgeport milling machine that can true of the venturi gasket surfaces....any machine shop should be able to do it. When complete recheck metering block pin holes for correct depth.....good luck.