Jetting recommendations for single 46 setup

[kurtwolff]

I will be putting on a new intake setup this weekend, and wondered if anybody would have an idea what jets/popoff/spring/needle/seat/screw settings combo would be good to start off.

-T cases, no porting
-Riva single intake with Mikuni SBN 46 (over the counter) - stock flame arrestor - Vforce3 reeds
-Choke removed
-Stock stroke, stock bore, Wiseco Prolite pistons
-X cylinder, minor porting from Judge
-170ish compression, with Protec C-3 head
-Rev limit removed, I may run an enhancer
-B pipe with shortened B1/Raider MOD chamber (looks very similar in shape to a TNT now)
-Lightened X flywheel/stator
-Jetworks flow control vale

I would like to know what would be a good start for jetting/tuning this, so if you have a similar setup, chime in please!

 

[demolition_x]

this is what chucky told me.

2.3 needle valve with a 95 gram spring, 125/127.5 pilot, 130 high jet and make sure you use 2 check valves on the metering plate. I have forgotten if the low speed needle is the very fine thread or the course thread, just compare the low needles to the high needles and if about the same thread pitch, it's the course one. If you have the course thread low needle set to
1 3/8-1 1/2 out, if it's the fine thread start at 2-2 1/4 turns out, with the high at 1 turn

 

[kurtwolff]

Thanks man! Is your setup similar to what I will be running? What is different on yours?

 

[demolition_x]

some what. 61x, mild port, ada head 35cc, mod pipe.

it may be off slightly but he said its a starting point.

 

[douglee25]

this is what chucky told me.

2.3 needle valve with a 95 gram spring, 125/127.5 pilot, 130 high jet and make sure you use 2 check valves on the metering plate. I have forgotten if the low speed needle is the very fine thread or the course thread, just compare the low needles to the high needles and if about the same thread pitch, it's the course one. If you have the course thread low needle set to
1 3/8-1 1/2 out, if it's the fine thread start at 2-2 1/4 turns out, with the high at 1 turn

Could you elaborate on the reason to use 2 check valves?

Doug

 

[demolition_x]

no idea. i didn't get that far. when i do i was gonna call him up.

 

[douglee25]

I think (if my memory serves me correct) that keeps the engine from falling on it's face after you let off from a high speed run.

Doug

 

[lerott]

With 61X cases, I use 2.5 needle valve with a 65 g spring (pop off 14 psi), 125 pilot, 160 high jet
low = 1.5 turn
High = 1 turn

 

[kurtwolff]

I think (if my memory serves me correct) that keeps the engine from falling on it's face after you let off from a high speed run.

Doug

That seems to be what I can gather from the Mikuni manual also...