oem 44 questions

[aqua]

I just bought a set of dual oem 44's with stock f/a and stock intake manifold. when looking at them i noticed a couple of things.

first, the carbs mount backwards compared to my 38's....even the throttle cable attachment is now on the rear of the carbs vs. the front of the carbs where it is on my 38's. the throttle/choke cable mounting plate mounts on the back on the manifold too.

second, they have primer fittings built in to the f/a mount and they have choke plates that I was thinking about removing.

how are you guys mounting these things and still having access to the adjustment screws. i would like to turn them around so that they are facing the same way that my 38's mount but if I do then my bolt holes in the intake manifold that hold the throttle cable mounting plate will be on the wrong side. how is everyone mounting these.

also i am wanting to take out the choke plates and will need to plug in the choke shaft holes. i guess i could jb weld that too unless someone has brass plugs that i can plop right in. thanks yall. :biggthumpup:

 

[Matt_E]

The fittings in the flame arrestors are for the oil injection of whatever engine they came from. I guess you can run the primer in there and just plug the holes of the choke shafts.

There are a couple of different ways to go about the throttle cable mounting.
First, ideally you want to run the carbs with the diaphragm side (diagonal) to the cylinder (or pumps/fittings on the outside) - that is supposedly the best for power.
Unfortunately, your stock throttle cable will be too short/almost too short for that.
You can get a throttle cable bracket that mounts to the diaphragm cover of one of the carbs, or to the pump side of one of the carbs. They cost 25 bucks or so - Blowsion has either version.
Or you can get an aftermarket manifold, such as the Riva or R&D Dominator which have mounting ears for the throttle cable on both ends.
Those options are $200+

 

[Boris]

My understanding is that the square nose throttle cable is longer than the round and should work.

 

[Matt_E]

It does. With a shortened pole, the roundnose cable works, too.
And I am pretty sure that a $25 dollar bracket is cheaper than even a used throttle cable. :biggthumpup:

 

[Boris]

That indeed is true unless you have a lead on a freebie. :biggthumpup: :biggthumpup:

 

[Matt_E]

Free is better than $25. :biggthumpup:

 

[norcal ex]

What i did was turn them around to run them like the 38s (wanted a short pulse line) and then drilled and tapped the manifold to accomidate the throttle cable on the new side. this also made it so i can run my stock throttle cable...

 

[just joe]

First, ideally you want to run the carbs with the diaphragm side (diagonal) to the cylinder (or pumps/fittings on the outside) - that is supposedly the best for power.

Anyone ever prove this to be the case? Not that I am questioning the logic, but wonder if it's been proven.

"regular" or pump facing out, and the fuel bounces off the throttle plate (in any position but WOT) and takes a quick 90 into the reeds.

"goofy" or pump facing toward motor, and the fuel gets kinda split by the butterfly (except WOT) with majority taking a longer path into the reeds, allowing for better atomization?

Just thinking about it makes me wonder.

 

[Matt_E]

I don't know. :dunno:

 

[aqua]

why would mounting them with the pumps on the outside give more power???......and how would you get to your adjustment screws with your cylinder in the way if you mounted them like this.

norcal......i was actually thinking about doing what you are saying about tapping the other side of the manifold....even has two little indented circles there saying, "hi, drill and tap here".

i do have a -3 inch pole that i will installing also so i just might have enough throttle cable to mount them with the pumps out....but still...if i do then it looks like getting to the adj screws will be a total pain.

what to do? :dunno:

 

[Matt_E]

How are the adjustment screws any more or less in the way one way or the other?
Diaphragm in: screws on one carb accessible, not the other
Pump in: screws on one carb accessible, not the other

How often do you mess with the screws? :dunno:

 

[SkiDaddy]

I asked Paul (LPW) this question and he recommended throttle wheel to the rear & a SN cable.

 

[aqua]

How are the adjustment screws any more or less in the way one way or the other?
Diaphragm in: screws on one carb accessible, not the other
Pump in: screws on one carb accessible, not the other

How often do you mess with the screws? :dunno:

with the pump out the screws in the middle will be on the cylinder side of the carbs. right now i can adjust my screws without taking the f/a off.

why is it that everybody recommends running the pumps out? what kind of benefit could there be???

 

[just joe]

Honestly, I am willing to bet that most people wouldn't notice a difference. And when you are at the point of needing just a little extra throttle rsponse, flip 'em around.

 

[SUPERTUNE]

Just Joe, Yes, I have done my homework and I have proven to myself that carbs mounted w/ the diaphragm mounted to the cylinder side work better. I did a lot of testing. My engine packages prove it works....

 

[Matt_E]

:biggthumpup:

 

[michael950]

Anyone ever prove this to be the case? Not that I am questioning the logic, but wonder if it's been proven.

...

Just thinking about it makes me wonder.

Just Joe, Yes, I have done my homework and I have proven to myself that carbs mounted w/ the diaphragm mounted to the cylinder side work better. I did a lot of testing. My engine packages prove it works....

I think Ed Brazina has also done his homework. He does bench flow bla bla bla tests in his shop. (Don't ask me, I have no clue who Adam is). Boysen, Carbon Tech, VForce, etc. all compared and with different manifolds...

There's a reason the R&D and Boyseen Intake manifolds and full spectrums are with drum south (throttle linkage aft).

 

[crammit442]

I think Ed Brazina has also done his homework. He does bench flow bla bla bla tests in his shop. (Don't ask me, I have no clue who Adam is). Boysen, Carbon Tech, VForce, etc. all compared and with different manifolds...

There's a reason the R&D and Boyseen Intake manifolds and full spectrums are with drum south (throttle linkage aft).[/QUOTE]

The main reason to run carbs w/fuel pumps away from the motor(on superjets) is to eliminate the possibility of the vent hole on the other side from being covered by the rear exhaust tube. It's happened to many people. I don't believe there is a real advantage to mounting the carbs either direction on a standup. The carbs are going to experience identical shaking forces side to side and front to rear on a standup. Even on runabouts where the g-forces are high enough to make a difference, the normal solution is to rotate the carbs 90 degrees.:smile:

Charles

 

[nikad58]

I think... use a raider,blaster,vxr any sit down throttle cable (for you long poler's) and skip all that stuff and it will give you lots of room to route it nicely and go ride !!!.. with a -3 pole there is plenty of room to just mount it up.. i only have limiteds with stock 760 44's and have yet to hear.. boy you should turn them carbs around to get a little more !! I hear, Damn thats a good running ski !
Mine snap very very well !!

 

[just joe]

Supertune - I believe you with data, hard to argue. Could it be that it has more to do with butterfly angle w/r/t site bomb and fuel outlet holes than location of pump close to engine or away? and likely (just guessing, I don't have the data) it is more detectable at partial throttle than WOT. But would your average Joe notice?

I think Ed Brazina has also done his homework. He does bench flow bla bla bla tests in his shop. (Don't ask me, I have no clue who Adam is). Boysen, Carbon Tech, VForce, etc. all compared and with different manifolds...

At WOT, I really struggle to understand more flow due to carb position alone. Carb diameter is fixed, Butterfly is parallel to throat in either position.


-Just Joe's opinion