blue thunder

The 2 screws that go in to the metering block on the front are the idle mix screws. The one screw that acts as a throttle stop is the idle screw. No such thing as air bleed screws.

Like mrfixx and I said, start at one turn out on the mix screws and go in (cw) evenly with both until the problem resolves.

Thunderstruck

Rick, I run the idle screws in a little at a time with the boat in gear idling until the motor dies. Then back out 1/8 or 1/4 turn on each idle screw. Needs a lot of warmup to idle but doesn't load up.

ezstriper

also put a timing light on it, make sure the timing is not backing off when you put in gear...that will act just like a carb issue..Rob

qaberdeen

Man, r any of u guys coming to Bermuda soon..I had the same problem last season..I recently sent the carb back to be recalibrated..haven't sea trailed yet to see if it's any better..but will keep u guys updated..n i only have 12hrs on this motor..

qaberdeen

rssteiny.. i feel your pain..mines does the same thing..idles fine.. around 950rpms, but once in gear and under load it drops instantly to around 650rpms and stumbles n wants to cut out unless i come up on the throttles..i ready to sacrifice speed for a dock friendly boat..good luck.but if u have any findings please advise..

Q

jeff1000man

The air bleeds on that carb are not adjustable. They are bulit into the metering blocks on the top/ That is also something to check and make sure that they are not cloged or restriccted. You can pull the bowl screws off the front of the carb. the metering block is sandwiched between the carb and the main body. Blow air from the bottom openings of the metering block out so that any debris comes out of the block instead of going in further.

You may just want to buy an upgraded carb from holley with 4 corner idle circuit since you have gone to the steeper cam to help the engine out.

rssteiny

I have a set of 2 year old bg demonds 875s maybe i should try them just need to do some different plumbing. Im going to play with the holleys this weekend on the water see what happens first ill let you all know.

Thanks

rssteiny

What size cams are you running, how is it working this year.

Thunderstruck

I run Bob Madara's cams that are ~228 I, 232 E duration with ~.598 lift on both I & E, pretty mild idle but they pack the charge in really well on the top end. Peak hp is at 5500 rpm. I am still in the 90-91 mph range but looking to do another project with Bob this year to take it up another notch.

rssteiny

You spinning 30s at 5500 with nose cones right.