Need help with chasing down an air leak

[RMBC Freeride]

OK, finally... here are the jetting on 2 sets of Novis I have run (take it FWIW). Obviously these are not reverse jetted as I had thought. And of course no 2 setups are alike... these arent even close to yours!!! good luck!

5mm Able stroker in my SJ 753cc
44mm Novis
Pilot Jet- 117.5
Main Jet- 125
Valve Seat- 2.0
Spring- 95 Gram (cut 1.5 coils off) to get 21psi pop

777cc Polaris Octane
46mm Novis
Pilot Jet- 127.5
Main Jet- 142.5
Valve Seat- 2.0
Spring- 95 Gram
(this ski is still a little too rich but it starts easily every time)

hope this helps a little... :fing02:

 

[Mark44]

Damn geek from the 44 observation thread to this are you a glutton for punishment? LOL

Mark44

 

[freestylegeek]

OK, finally... here are the jetting on 2 sets of Novis I have run (take it FWIW). Obviously these are not reverse jetted as I had thought. And of course no 2 setups are alike... these arent even close to yours!!! good luck!

5mm Able stroker in my SJ 753cc
44mm Novis
Pilot Jet- 117.5
Main Jet- 125
Valve Seat- 2.0
Spring- 95 Gram (cut 1.5 coils off) to get 21psi pop

777cc Polaris Octane
46mm Novis
Pilot Jet- 127.5
Main Jet- 142.5
Valve Seat- 2.0
Spring- 95 Gram
(this ski is still a little too rich but it starts easily every time)

hope this helps a little... :fing02:

Thanks Neil! It's always good to know what works on other skis. Looks like there's a big difference between the 46's and 44's (and my 48's).

I re-jetted last night to the following
Low - 130 (no change)
High - 115
Seat - 2.3
Spring - 115g (f0r 24 psi pop off)

It seemed to significantly reduce the amount of fuel splashing onto the head. However, at anything less than 1-1/4 turn on the bottom screw, I encountered run-on if I stabbed the throttle. I could eliminate the run-on if I significantly lowered the idle, but I brought the low screws to 1-1/2 and that took care of it.

The next thing I'm trying to figure out is why I can set the idle to a good RPM, but when I give it a full throttle burst, it drops back to well below that point, then slowly comes back up (maybe 5-10 seconds to return to normal). I think that it will just die when I try it in the water (which sucks for monkey jumps). Does anyone know what causes that situation?

 

[freestylegeek]

Damn geek from the 44 observation thread to this are you a glutton for punishment? LOL

Mark44

It's all because I want that stupid flat water backflip! :AR15firing:

 

[waterfreak]

Maybe you should try one of those single carb set up!:thinking::shrug:

 

[Matt_E]

Looks like there's a big difference between the 46's and 44's (and my 48's).

Of course there is. :dunno:
Differerent sized carbs, different air velocity, different vacuums.
You cannot compare jettings from different sizes carbs

Maybe you should try one of those single carb set up

That wouldn't solve the problem, it would merely cut it in half.


Matt, it might be time to go back to basics.
Read this, then take a starting point and tune from there.

 

[Big Kahuna]

Thanks Neil! It's always good to know what works on other skis. Looks like there's a big difference between the 46's and 44's (and my 48's).

I re-jetted last night to the following
Low - 130 (no change)
High - 115
Seat - 2.3
Spring - 115g (f0r 24 psi pop off)

It seemed to significantly reduce the amount of fuel splashing onto the head. However, at anything less than 1-1/4 turn on the bottom screw, I encountered run-on if I stabbed the throttle. I could eliminate the run-on if I significantly lowered the idle, but I brought the low screws to 1-1/2 and that took care of it.

The next thing I'm trying to figure out is why I can set the idle to a good RPM, but when I give it a full throttle burst, it drops back to well below that point, then slowly comes back up (maybe 5-10 seconds to return to normal). I think that it will just die when I try it in the water (which sucks for monkey jumps). Does anyone know what causes that situation?

almost sounds like you are lean on bottom or that when you pull full throttle, it is sucking all the gas out and when you let off, it is having to catch up, maybe like the fuel pump is not working suffeciently.

 

[freestylegeek]

almost sounds like you are lean on bottom or that when you pull full throttle, it is sucking all the gas out and when you let off, it is having to catch up, maybe like the fuel pump is not working suffeciently.

I kinda wondered about that too. Both pumps are at 2psi at idle which is spot on. I'm quite certain fuel pressure isn't an issue.

 

[freestylegeek]

...Matt, it might be time to go back to basics.
Read this, then take a starting point and tune from there.

I could recite that book to you! I've read it an average of 5 times a day for the past year. :Eyecrazy:

 

[Matt_E]

LOL....at some point it might be better to start from scratch and throw all previous assumptions out the window.

At least it's fall/winter.
No pressure to get it done ASAP.

 

[crammit442]

Thanks Neil! It's always good to know what works on other skis. Looks like there's a big difference between the 46's and 44's (and my 48's).

I re-jetted last night to the following
Low - 130 (no change)
High - 115
Seat - 2.3
Spring - 115g (f0r 24 psi pop off)

It seemed to significantly reduce the amount of fuel splashing onto the head. However, at anything less than 1-1/4 turn on the bottom screw, I encountered run-on if I stabbed the throttle. I could eliminate the run-on if I significantly lowered the idle, but I brought the low screws to 1-1/2 and that took care of it.

The next thing I'm trying to figure out is why I can set the idle to a good RPM, but when I give it a full throttle burst, it drops back to well below that point, then slowly comes back up (maybe 5-10 seconds to return to normal). I think that it will just die when I try it in the water (which sucks for monkey jumps). Does anyone know what causes that situation?

Next time the motor wants to run on, reach inside the motor compartment and physically use the throttle wheel(NOT relying on the return spring to close the plates) to force the plates against the idle stop screw and see if that stops the run on.

 

[freestylegeek]

Next time the motor wants to run on, reach inside the motor compartment and physically use the throttle wheel(NOT relying on the return spring to close the plates) to force the plates against the idle stop screw and see if that stops the run on.

Good call Charles. That's what I did a while back when I discovered the throttle wheel had a small burr on it that caught the throttle cable. That one messed with me for a few weeks. That's the condition it had up at wave rave.

 

[QJS]

Try a 95gm spring, if the carbs are still "dribbling" you need to address the vibration issue.
Chris.

 

[waterfreak]

Maybe you should try a different set of carbs. Maybe a set that you know are dialed in to make sure it is the carbs.

 

[djkorn1]

good call, steve. That will eliminate all other problems.

 

[freestylegeek]

OK, rode this weekend and it's fine at 1/4 throttle and up. It doesn't idle well and the longer I ride it the longer it takes to start. It usually takes a good 5-8 seconds of turning over (with NO throttle) in order to start once it's been running. If I pull the throttle at all or prime it, it takes even longer. I'm going to talk to Tim about it again and see what else to look for. Maybe the carbs need to take a trip to Florida for an inspection...

 

[djkorn1]

Are the carbs syched (sp.)???? Mine was having problems starting and idling and I found that they were out of synch a little bit. Made HUGE difference.

 

[Mark44]

Do you still have your 44's give them a try.

Mark44

 

[eel]

Where is the idle adjuster? Sorry, how many turns out is the low speed screw?

 

[freestylegeek]

Are the carbs syched (sp.)???? Mine was having problems starting and idling and I found that they were out of synch a little bit. Made HUGE difference.

Dead even. I've checked that a lot.