Tune and jetting Dual 46s

So ive been trying to search for a set up like mine but most people seem to be at different ends of the spectrum. Ive had a hell of a time the last couple months with this boat and Now Just need it to hit like it should.

1) what is the proper tunning procedure? I have read a few different things. I will not have access to a tach.

2) I do not have any more $$ or time to wait around on shipping and selling stuff off for different things. I simply want to get her running, be able to do some tricks and not worry about my ski dying or falling flat on its face when i punch it.

Im open to all opinions but im trying to keep all that i have with exception of buying new jets and minor cheap things.


Setup:
701 62t Cases
Mild port Job on exhaust and B-pipe
Factory Limited B-Pipe
R&D Girdle head
TDR Waterbox
Carbon Reeds
Protec Dual 46 manifold with cross chamber
Dual Mikuni "riva" 46s (came frome a race ski was told) The jetting on the 46s was 115 for the Bigger jet, and the smaller in size jet was a 120. I am clueless to jets and jetting. I do learn fast though!

I figure my jetting has to be off if it did come from a race ski. I need as much low end as possible. I could give a care if my ski ever made it past 40mph



Please any and all help is much accepted. I just want to enjoy riding and stop wrenching (atleast on my ski). And once again less money invested at this time is crucial (just recieved an awesome 300 dollar ticket for having my boating liscence card in my car and not in my pocket)
 
Last edited:

Proformance1

Liquid Insanity
Site Supporter
Vendor Account
Location
New York Crew
Call Frosty and meet us at Sturgeon, he is the man on tuning around here, he worked with me on mine and it perfect. I have a brand new tiny tach in my garage, but i didn't use it. Is anything besides the rebuild and light port work new from last year?
 

Mark44

Katie's Boss
Location
100% one place
p

So ive been trying to search for a set up like mine but most people seem to be at different ends of the spectrum. Ive had a hell of a time the last couple months with this boat and Now Just need it to hit like it should.

1) what is the proper tunning procedure? I have read a few different things. I will not have access to a tach.

2) I do not have any more $$ or time to wait around on shipping and selling stuff off for different things. I simply want to get her running, be able to do some tricks and not worry about my ski dying or falling flat on its face when i punch it.

Im open to all opinions but im trying to keep all that i have with exception of buying new jets and minor cheap things.


Setup:
701 62t Cases
Mild port Job on exhaust and B-pipe
Factory Limited B-Pipe
R&D Girdle head
TDR Waterbox
Carbon Reeds
Protec Dual 46 manifold with cross chamber
Dual Mikuni "riva" 46s (came frome a race ski was told) The jetting on the 46s was 115 for the Bigger jet, and the smaller in size jet was a 120. I am clueless to jets and jetting. I do learn fast though!

I figure my jetting has to be off if it did come from a race ski. I need as much low end as possible. I could give a care if my ski ever made it past 40mph



Please any and all help is much accepted. I just want to enjoy riding and stop wrenching (atleast on my ski). And once again less money invested at this time is crucial (just recieved an awesome 300 dollar ticket for having my boating liscence card in my car and not in my pocket)

Get a tach and properly tune the motor you will be glad you did. More HP better starting and longevity. Borrow one rent one whatever it takes, you spent all this time and money on your motor why cut corners at the end of the race?

Sure there are a lot of armchair tuners on this site just ask and you will get every answer you are looking for then some.

Mark44
 

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
Do you have just aftermarket Mikuni 46mm carbs that Riva sold or are they modified inside?
A basic jet format with standard dual Mikuni 44/46mm carbs to see where you are would be:
100 high 1 1/4 turn out
125 low 1 3/8 turn out
2.3 needle valve
80 gram spring
This should have you on the rich side and can jet from there.
Use a Jetworks flow control valve for your water feed on the chamber at the stinger.

P.S. If you have a intake manifold that has a crossover passage...you need to fill it with 2 part epoxy to completely block it off.
 
Do you have just aftermarket Mikuni 46mm carbs that Riva sold or are they modified inside?
A basic jet format with standard dual Mikuni 44/46mm carbs to see where you are would be:
100 high 1 1/4 turn out
125 low 1 3/8 turn out
2.3 needle valve
80 gram spring
This should have you on the rich side and can jet from there.
Use a Jetworks flow control valve for your water feed on the chamber at the stinger.

P.S. If you have a intake manifold that has a crossover passage...you need to fill it with 2 part epoxy to completely block it off.



what is the reason for epoxy on the crossover? Figured it would help out...

with my stock 38s i was not running a flow control valve. I know it helps with performance but if i go with out it with the 46s will it make a big difference?


So seeing that i have 115 for the low and 120 for the highs im running pretty rich then i take it?
 

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
Your golden with these carbs!
We carry just about 6-8 of every size OEM Mikuni jets and needle valves with any of the gram springs (4).
These are retail aftermarket 46's from Mikuni.
Jetworks valve helps the carbs be able to run a big low jet for hit and not load up the waterbox.
Makes the carbs not stumble from the bigger jet by having less back pressure.

I don't like filling the crossover for 38mm stock carbs as they don't like it, the fuel circuit in them were made for the crossover.
The 46's will work much better without the crossover.
 
Now listen to Supertune and fill in that crossover!
The reverse jetting of those Riva carbs was used on their strokers when skis had barney purple trim but still works today!
 
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