Carb return jets

DAG

Yes, my balls tickled from that landing
Location
Charlotte, NC
3 things

Tune fuel pressures vs stuck with what you got.
Reduce chance of debree clogging the tiny .030" orifice vs 1 larger one.
Reduce chance of pump side pressure spikes blowing out / kinking the clear circle one way valves
 

Jr.

Standing Tall
Staff member
Site Supporter
Location
Hot-Lanta
3 things

Tune fuel pressures vs stuck with what you got.
Reduce chance of debree clogging the tiny .030" orifice vs 1 larger one.
Reduce chance of pump side pressure spikes blowing out / kinking the clear circle one way valves


Hang on here, Not so fast.............

It equilizes pressue between both carbs, so pop-off pressures are constant.
Debris? Thats what fuel filters are for!
Those little discs are check valves. Not enough pressure present to blow them out if they were installed correctly?

Ok, carry on!


Ski ya, Paul
 

DAG

Yes, my balls tickled from that landing
Location
Charlotte, NC
Debris? Thats what fuel filters are for!
Agree, I just have bad luck, I found mine clogged years ago and run an internal filter. Perhaps washing hands and working in a less than clean environment played a roll into that? Also XS guys did (and maybe still do) recommend running w/o the internal filter. Actually kinda curious if there billet carbs even have a spot for one? For whatever the reason if poop finds its way in its more likely to just pass on through hassle free

Those little discs are check valves. Not enough pressure present to blow them out if they were installed correctly?
check valves / one way valves... I had this problem when I swapped a 1200 into a B1. Keepted replacing check valves after check valves. Its a common problem for triples not sure if duels have the same problem? Or maybe its a AM vs OEM mikuni thing? source: http://www.greenhulk.net/forums/showthread.php?t=177671

I'm not sure what Frank has up his sleeve but know he's a blaster guy and might be considering a triple? Drilling doesn't have any negative side effects as far as I know. Cant think of a reason not to do it but can come up with 3 reasons to do it
 
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Thanks ... Im just really trying to '' fully understand and learn '' the why and how of carb tuning/jetting on on our skis and presently trying to jet 2 different skis ... I have started writing down all the adjustments '' like LPW recomended '' on each ski and it really helps so far . Thanks for all the input from everybody ... thats how we learn
 
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as soon as you drill those out and change the restrictor size, the jetting is totally changed. the bigger the return jet size, the less fuel pressure which means less fuel going to the motor and more back in the tank. a lot of AM carbs need a restrictor jet. i'm pretty sure its a 60 jet. you don't tune your ski by reducing or increasing fuel pressure. I saw just that being done in another thread and I just had to shake my head in disbelief. if the carbs have built in restrictors, there is no need to drill them out. blackjacks, buckshots, riva power bombs, red tops all have them in the carbs. novi, full spec dont
 
Look closely. You don't have to tune the pressure but there might be some truth to getting the 5 psi Novi recommends. I got 7 psi at w.o.t. when I had external pump and 60 jet. Never really messed with tuning that but one time. Tried 80 jet and it got the 5 psi and yes the motor ran completely different.
 

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