Jetting for sbn 44 superjet help

[KodeKat]

OK so i'm getting close to finishing my motor build and I need some help. Engine specs:

61x\61x 84mm, fresh over bore
.02 shaved off the head
freestyle ported
port matched b-pipe (Mod)
Single Tau F\A on top of a stock 44mikuni

Now, can some one help me out and inform me what is a good starting point for the jets\springs and such on the carb?

From Factory I found the general settings for a 701 to be :
Main Jet : 145
Pilot Jet : 120
High speed screw : 12 turns out from closed
Low speed screw : 2 2 turns out from closed
Needle & Seat : Stock
Spring : 95 gram

Where should I go from there? Also, if your selling what I need feel free to send me a PM. Thanks- Tom

 

[KodeKat]

Any1?

 

[ryan]

sounds like a good starting point. 125 low is about all i would do. to start with.

 

[SUPERTUNE]

I would go bigger on the needle valve to lower the pop off for some decent fuel pressure, then like Ryan stated, go up on the low jet to 125-127.5 and smaller on the main jet if your too rich.

 

[KodeKat]

Thanks guys, I'll try those and see how it goes. -Tom

 

[KodeKat]

OK, UPDATE... Now I've done it... The super Frankenberry...

I'd like to get your guys input or find someone who is running close to the same set up as me. I need some help getting 'er dialed in.
Here is what my boat has:

61x\62Tx 84mm Frankenberry,
ADA full girdled head, 33 domes
freestyle ported
port matched b-pipe (Mod), restricted stinger
MSD enhancer
Dual Prok's F\A sitting on top Dual taper bored 38's

currently the 38's have:
85 pilot
140 main
25psi pop-off

Now... what do you all think I should start with for the carbs? Any help is appreciated. -Tom

 

[KodeKat]

?

 

[Mark44]

Read.
http://www.x-h2o.com/threads/39846-Tuning-tips-for-Rookies.

Mark44

 

[KodeKat]

Any one have any info on tuning? I took it out this past weekend and it was lean in the top end\pop. We raised the main(s) up to 155 and it still needed more fuel, would bog after WOT, but if i pulled the primer it ripped off of my arms. Think I need a set of 44's or 40's? Do I need a set of 38's with dual fuel pumps? The pop-up was somewhat ridiculous, around 30 or so. What do you all think? -Tom

 

[Mark44]

See post #8

Mark44

 

[KodeKat]

Thanks again Mark, but I have read it and gone through the whole tuning process a multitude of times. I am trying to find someone who is running a similar setup, not just a 'how to tune manual.' Thanks for the information but I believe the situation involves changing carb set-up\adding an additional master fuel pump. The intake velocity of the tapered 38's is great but I don't think they can deliver the sustenance my Frankenberry is asking for.

 

[kevbo]

Thanks again Mark, but I have read it and gone through the whole tuning process a multitude of times. I am trying to find someone who is running a similar setup, not just a 'how to tune manual.' Thanks for the information but I believe the situation involves changing carb set-up\adding an additional master fuel pump. The intake velocity of the tapered 38's is great but I don't think they can deliver the sustenance my Frankenberry is asking for.

I see in your description that the carbs have been bored. Thats your problem. You may need stock flame arrestors to some fuel draw back that the hatchet job killed.