48 Novi's?

I have a set of 48 max flows I have installed on my Superjet. It is a 5mm stroker with 85.5 bore and a Speedwerx race pipe. The motor does not have any air leaks but the 3 times I have tried to start it since assembly it wants to rev to the moon. The spring almost seems like it is not strong enough to always close the butterflys all the way? Sometimes it will but if you open it a bit and let off they dont close all the way. The carbs seem to be in sinc. They are jetted as follows.
140 pilot
125 main
2.3 needle & seat
95 gram spring.
2 1/2 bottom
2 top
Anyone have any suggestions? I also have a call into Tim at Novi.
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
Do the plates close fine without the throttle cable attached?
If so, make sure there are no kinks in the cable and that it moves freely.
 

njfl

X-H2
Do the plates close fine without the throttle cable attached?
If so, make sure there are no kinks in the cable and that it moves freely.

Agreed.

Don't even look into jetting. Focus on the fundamental mechanical operation.
 

Big Kahuna

Administrator
Location
Tuscaloosa, AL
disconnect the throttle and crank the ski, see what happens. A lot of times it is either the cable is adjusted wrong, idle set to high or one of the throttle plates is out of sinc and it does not take much.
 
The throttle shafts/seals may need a little lubrication, or the spring itself could be covered with junk. also check the shaft couplers, either the set screws could be hanging up on the carb body, or the couplers are too tight on the shaft, etc etc...
 

Lakeman

Stand Up All The Way
Location
Wichita, KS
I had the same problem with mine. My pop off pressure was too low. At idle the motor shakes a lot and gas shakes out.

Rev your ski and look down the ceneter of the carb's. Let off the gas and see if see the gas spilling in.
My soloution was to replace the springs and needle and seats.

Dale
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
Make sure your cable is really okay. You don't want to be thinking it's okay only to have it stick wide-open on the water.
 
I had a set of brand new Novi's last year and i loved how stiff the throttle spring was. These don't seem to have such a stiff spring. Where can I get a new spring for these?
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
Any place that sells Mikuni SBN parts.
They all use the same spring, if I am not mistaken.
 

#ZERO

Beach Bum
Location
Florida - U.S.A.
I believe the springs are the same as OEM.

Just remove the spring, cut the tab off and re-bend the new angle shorter with some needle nose pliers for more tension.
 
Do throttle springs wear out? I mean these carbs were only used once before I bought them. They look like brand new. I have never had to replace a throttle spring before.
 
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