MAC 84 Carburettor

[CConrad]

Hello from Germany

I bought a Mac 84 Carb, to try it on my K90 ( the new one with the double intake rotor ) Now i'm very astonished, that this carb doesnt have a needle ore something similar for the lower end of throtteling. I have to change a little bit on the carb to fit on my engine, but before i will do that, i ask you, if you think, that will work well. I dont know how it will throtteling well without having some mixture control for the lower end????????

I want to fit this carb, because it has a much bigger bore ( 12,7mm ) than the original one ( 11mm ) and i hope i can get some little more power

Thank you for your information

Curt

 

[Eric Canto]

Curt, what makes the larger bore better?

 

[CConrad]

i hope, this larger bore will better hamonize with the double intake drumrotor, but that wasn't my question

Greetz

Curt

 

[Lamar_Huff]

Obviously w/o a low speed needle the engine is going to be extremely rich at less than 1/2 throttle or so... I have a new CMB .67 Green Head and the carb that comes with it does not have a low speed needle either. Some guys seem to live with it while others change it out for an OS9B (I think) because it has a low speed needle. I am still trying to get the boat dialed in so I have not decided which route to take yet.

Later,

Lamar

 

[Preston_Hall]

You will find that most riggers don't use a low end needle. Same goes for some monos. The speed at which the low end needle would be effective is barely obtainable by outriggers.

To answer your question, you will be fine and may find yourself removing needles from other carbs.

 

[RaceCraftBearings]

Hello Curt, I cant say how it will do on your K motor but I run a Mac 84 with the stock carb in a Seaducer Mono and I can idle around with no problem then when I go full tilt it delivers then as well.

Ron

 

[Anders_Martinelle]

Curt i run the 14mm carb on one of my K90 engines and i can just say that it works just fine.

I use the std 12mm carb that has no low end adjustment and that works fine to.

Performance wice it`s not a difference.

Anders

View attachment 2307

 

[CConrad]

ok, thank you all, i'll try it this weekend and we'll see, how it works.

I'll ceep you informed.

@Anders

have you also tried the new K90 with the new intake rotor?

View attachment 2308

 

[Anders_Martinelle]

I have seen it some years ago and was not impressed.

What`s wrong with the normal one???

Anders