What carbs to run on my engine?

RSKI

RSKI

Location
Oregon
I am no expert when it comes to selecting carbs, so I'm looking for some opinions on what I should run. Please consider my points listed below, I will list what's important to me.

Engine, hull, electrics, pump, and desired outcome:

771 old school Able billet cylinder, 82mm bore, 4mm stroker, 61x zero wheel. Foot rocket. Superjet oem electrics with msd enhancer, 144 skat mag. B-pipe with limited chamber. VF2 reeds, and right now I have a 760 intake mani on it, but I understand I may need to change that for some carbs, so that isn't an issue.

ehame4an.jpg


Desired outcome is having a setup that is reliable and a good all around performer in surf and flat water. I'm running a cold fusion fuel tank (5+ gallons) as I sometimes take pretty long distance rides, so fuel economy is moderately important to me. I live in Nebraska right now, but hope to relocate near surf in 2014, and I want my boat to be ready when I do.

As far as budget, I am open to consider anything from 38s to 46mm full specs. I don't mind spending money as long as I'm spending it wisely. Please help me do that.

Sorry for the long winded post, I've been struggling with this decision for weeks.
 
Last edited:
user_error

user_error

Location
seattle area, Wa
maybe consider some regular 46 sbn mikunis. relatively cheap compared to novis and full specs but still will feed enough fuel. wont suck nearly as much fuel as novis or full specs either
 
sjetrider

sjetrider

615 Freeriders are addicted to T1 madness.
Location
in the 615 (Nashville)
46's are nice but they have a bog issue when laid to side occassionally. I recomend BRAND NEW Mikuni 44's on a nice Riva or Protec manifold. If you have the extra fundage go with a Dasa or Boyeson Manifold for easy removal / jetting reasons.
The 44's will be enough for what you have now but would need upgraded should you go to a big more.
 
RSKI

RSKI

Location
Oregon
Forgot to mention I'm using vf2 reeds/cages. I think those aren't compatible with the boyesen mani? Thanks for the input guys. Much appreciated, and I'm still listening as I have some time before I need these.
 
RSKI

RSKI

Location
Oregon
sjetrider said:
46's are nice but they have a bog issue when laid to side occassionally. I recomend BRAND NEW Mikuni 44's on a nice Riva or Protec manifold. If you have the extra fundage go with a Dasa or Boyeson Manifold for easy removal / jetting reasons.
The 44's will be enough for what you have now but would need upgraded should you go to a big more.
Click to expand...

Is this bog issue from the exhaust hose covering the hole on the carb plates when leaning the ski on its side? (Drill an extra hole?)
 
sjetrider

sjetrider

615 Freeriders are addicted to T1 madness.
Location
in the 615 (Nashville)
rileym21 said:
Is this bog issue from the exhaust hose covering the hole on the carb plates when leaning the ski on its side? (Drill an extra hole?)
Click to expand...
I do not think so bro, I have turned the carbs the oposite way to test that theory and the bog just goes from the one side turns to the other. I have minimised it with higer popoff but it still exists. 44's just tune nice and are always crispy IMO. I am not sure if the Dasa manifold works with VF2 reads , they recomend VF3. The best manifold I have found other than those 2 is the wide base Protec. You can get the carbs and manifold from any Hot Products dealer. Jet Maniac can hook you up, we could to but we have all but quit selling parts and are all about building boats for sale soooooooo, rather ya call Chris Jetmaniac LOL.
 
BruceSki

BruceSki

Formerly Motoman25
Location
Long Island
I vote for 38's. I run them on my 771 big bore stock stroke motor.

Easy tune ability, great carb signal, excellent fuel range, good power. Relatively cheap.

Sure you can squeeze a bit more power out of bigger carbs, but the response is usually not as crispy as the 38's and it drinks way more fuel.
 
RSKI

RSKI

Location
Oregon
Ok, thanks to everyone's help and a few other people I've been plaguing with questions I have at least narrowed it down.

I think I'll go with a new set of SBN's, just need to decide size. I am definitely a bottom end type of rider, so the 46's make me nervous. 38's make me nervous to leave a lot of mid range on the table. Top end doesn't matter much to me, and I keep leaning toward the 44's since they don't have the bog issue and might be a fuel efficient happy medium for me.

Problem is I'm under qualified to make this damn decision, and 44's resale value is quite low.
 
js/sj

js/sj

Location
Grand Rapids
38's are to small for 701's in my opinion. Yea they might run decent but 44's work great on anything less than 900cc. They do dump a tad bit more fuel than 38's but they still are not bad compared to larger carbs. I love they way 44's tune and hit on small motors. Get 44's!!

Sent from my DROID RAZR HD using Tapatalk 2
 
jo5hi3

jo5hi3

Location
Charlotte NC
i have ran dual 46's on a ported 701 through a ss850.....i have never had a bog issue...they arent the greatest on fuel but if you want power then you have to burn fuel to make it.....
 
RSKI

RSKI

Location
Oregon
I'm leaning toward a new set of sbn 46's, should I have much concern of being short on bottom end hit? Thanks for the advice!
 
KTM434

KTM434

Jamie FN Hickey
Location
Palm Coast FL
rileym21 said:
I'm leaning toward a new set of sbn 46's, should I have much concern of being short on bottom end hit? Thanks for the advice!
Click to expand...

You won't have a bottom end issue at all. Strokers give a better carb signal anyway and you definitely won't lack bottom end with 46s
 
Big Kahuna

Big Kahuna

Administrator
Location
Tuscaloosa, AL
Contact XScream and get a set of 44's from them and have Chuckie do his mod to them. Not exactly sure what he does but they work well. I have ran them for years.
 
You must log in or register to reply here.
Top Bottom