Carb for MAC 21ob

[talonxracer]

I am having a very hard time getting the third channel mixture control to work properly. SO I want to go to a more conventional carb, what would be a good suggestion as far as a carb WITH a conventional needle set-up.

Doug

 

[Jerry Wyss]

I am having a very hard time getting the third channel mixture control to work properly. SO I want to go to a more conventional carb, what would be a good suggestion as far as a carb WITH a conventional needle set-up.

Doug

The O.S 20J that comes on the O.S.O/B will fit right on there.

 

[BobH]

20J is an excellent choice, plus the O.S inflight 3rd channel needle will fit.

 

[Joe_Knesek]

I'm running a D&J on my son's MAC and it throttles well.

 

[dave roach]

I'am runnong the Roach bell mouth carb and it works great.

 

[talonxracer]

I am having a very hard time getting the third channel mixture control to work properly. SO I want to go to a more conventional carb, what would be a good suggestion as far as a carb WITH a conventional needle set-up.

Doug

The O.S 20J that comes on the O.S.O/B will fit right on there.

I do have a XM21 and took the carb off and just compared them. The opening in the base of the OS carb is alot smaller than the MAC carb, will this affect performance at all? Would opening the throat at the base be possible or would that create more problems?

Doug

 

[Jerry Wyss]

Doug

[/quote

I do have a XM21 and took the carb off and just compared them. The opening in the base of the OS carb is alot smaller than the MAC carb, will this affect performance at all? Would opening the throat at the base be possible or would that create more problems?

Doug,

That part your concerned about isn't a big deal,,, the big deal would be getting enough fuel that

the Mac will require.

I use this carb on my Mod TT's with a one way check valve in the tank pressure line. The needles

don't have to be as far out with this method,,but still, allot farther out than they were on the XM.

I haven't ran my Mac yet but the 20J is definetly goin' on there with the check system. When this method

starts gettin' around "YS" ain't gonna be able to make enough check valves,,,

but it works well without the check too.

If you want to improve the 20J, that opening your talking about is "oval",,, make that part "round and

conical". You would need a lathe for this or a skilled hand with a taper reamer and dremel but it's not

imperative that you do it.

 

[james irwin]

I am having a very hard time getting the third channel mixture control to work properly. SO I want to go to a more conventional carb, what would be a good suggestion as far as a carb WITH a conventional needle set-up.

 

Doug

` AN EASY FIX to your delima would be to use one of my sump tanks ? that is what they are made for . NO FUEL STARVATION , THIS IS WHY FOR YRS WE HAVE BEEN ABLE TO RUN BIG BORE CARBS ON ANY MOTOR . ANY BOAT , UNDER ANY CONDITION . ASK ANDY HE WILL TELL YOU .

 

[XtremeRcBoats]

I've got a cmb carb on my MAC tunnel and it works very well.