os 40 size marine carb

[bob miller]

what , in your opinion , was the best os 40 size carb ?....thanks....bob

 

[Jim Allen]

Bob,

I use OS9-B carburetors on my .45 Nelson long strokes. It will be necessary to make an adapter plate for mounting the carburetor. The .4720" (12 mm) bore carburetor has both low & high speed needles coupled with automatic fuel metering. This makes the transistion from low speed to WOT speed very smooth & reliable once the needles are properly adjusted.

JA

 

[RaceMechaniX]

I would say the 9B is a little aggressive for most .45's. The 40A may be more appropriate http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCA69&P=7

Tyler

 

[HTV Boats]

Jim,

John Albritton is making carbs that fit perfect in Nelsons. And other motors. We set oval records with a .375 bore that transitions very well. Single needle. Before that the .340 red K&B won a lot of races. Get with John if you want larger. I personally think over .400 is not where you want to be. If it draws fuel and atomizes well that's better than larger.

Mic

 

[Terry Keeley]

I ran the 9B on my purple head CMB 45's for years, works great: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCE44&P=7

The 40A would also be a good choice. Do you need a bolt on or one with a neck?

 

[Jim Allen]

Jim,

John Albritton is making carbs that fit perfect in Nelsons. And other motors. We set oval records with a .375 bore that transitions very well. Single needle. Before that the .340 red K&B won a lot of races. Get with John if you want larger. I personally think over .400 is not where you want to be. If it draws fuel and atomizes well that's better than larger.

Mic

Hi Mic,

This carburetor does not need to "draw fuel". It uses tuned pipe pressure from the Silver Bullet pipe. The stinger has been reduced in size down to .3438" & extended to 4.500" in length.

JA

 

[bob miller]

I need a carb with a neck , it is going on a k/b 45 outboard....bob

 

[HTV Boats]

Bob,

K&B carbs are available at Mecoa. Again John Albrittom makes a carb that bolts in perfectly. I have one on a K&B 7.5 OB and it is as fast as any I have tried. Plus it transitions very well using only a single remote needle. Doesn't need an idle needle. Johns # is 239-677-7720 and his prices are very good.

Mic

Jim,

Been a while. Hope all is well with you and your family. (Semper Fi my friend). You are half right as we do have basically a pressurized injector (carb throttle body). There is also a fuel draw factor that uses bore size, ventury shape,(SP) and proper size and placement of the spray nipple for lack of better description. Johns experience with pylon racing and records with Nelson has made him a real asset to boat racing. I have never had my Nelsons run as well since he hooked in on the program.

Mic

 

[Michael Costanzo]

i used to run a os .46 with a .80 ops slide valve (.400 bore) and also ran it on a .45 CMB. great throttle response!!

 

[bob miller]

is the os 40 a carb the same as the os 40 d carb ...I need a carb with a neck....thanks....bob

 

[RaceMechaniX]

Neither OS carb has a neck, they are both flange mount. An OS 21D 10mm carb may work.

 

[El Zorro]

You outboard guys need to look into J.E. Albritton's carbs. He is an excellent machinist that I have known for more than 50 years. He even has carbs that you can screw in an O.S. inflight needle valve into. I have seen pictures and these pieces are beautiful. If you want the best out there give him a call.

Dick Tyndall

 

[bob miller]

I,m currently using a os 21 d carb , it works pretty good , just looking for a little more top end.....bob