Shiny silver 115g spring on 07 superjets

[Ericfox]

Dont make a change yet... I am waiting on Mike W to come back with a report on how his 115g springs are working on his setup... He said he should have time to get his ski out in the next week or 2.

 

[vjhardcore]

Changes

Dont make a change yet... I am waiting on Mike W to come back with a report on how his 115g springs are working on his setup... He said he should have time to get his ski out in the next week or 2.

Ok - But what are the springs your talking about and what do they do.

 

[Mike W]

Dont make a change yet... I am waiting on Mike W to come back with a report on how his 115g springs are working on his setup... He said he should have time to get his ski out in the next week or 2.

Last night it got cold as hell so I will be able to take it out one day next week. Should be warmed up by then. I will let you guys know.

 

[Ericfox]

Ok - But what are the springs your talking about and what do they do.

There are little spings in your carbs that along with your needle and seat (which I also assume you dont know)- control your popoff pressure (which maybe you dont know as well... )

I see you want to get up to speed on this, so go to the Mikuni website- go to manuals and download the pdf of the super BN carbs... read it well... then read some stuff on here... then go back and read it again... it may take a couple reads to fully understand how the carbs really function... you will get the basics though right away. Check it out....

 

[vjhardcore]

Come on! Monkey Man

There are little spings in your carbs that along with your needle and seat (which I also assume you dont know)- control your popoff pressure (which maybe you dont know as well... )

I see you want to get up to speed on this, so go to the Mikuni website- go to manuals and download the pdf of the super BN carbs... read it well... then read some stuff on here... then go back and read it again... it may take a couple reads to fully understand how the carbs really function... you will get the basics though right away. Check it out....

The nut shell version to ponder till I get a chance to read up on it more?:moon:

 

[Ericfox]

the needle/seat allows fuel to flow into the carb from the fuel pump- the spring is what resists the flow until the pressure from the case overpowers the resistance from the spring (then it pops the needle off the seat =popoff pressure). If you look at the diagram in that manual you can see it and visualize it happening...

Different springs have different resistance... the springs are identified by color which corresponds to a number in grams of the spring. The higher the number- the higher the force required to compress the spring==> the higher the popoff pressure.

 

[2006superjet]

i ran the 115g springs for up untill now they work to me. but now lookng into it and realizing that fp recomends the 95g so i went to jet works and got them my carb hi low were all jacked got that dialed in and installed the 95s and wow.. so far 1 button for sure it starts up with no hesitaion nothing before it was a lil slow kinda like pressing the power button on the tv remote a lil delay not much but a lil to startup. i also always had to give her a lil blip or 2 now the idel is alot cleaner and alot crisper bliping from my finger throttle instant brap no hestaion.

so far i would recomend using the 95g

i have not ran it in the water yet

 

[Mike W]

Well I took it out today and it still runs like crap on the low speed circuit. It runs real "muddy" just off throttle up to 1/4 throttle. Not sure where to go from here but I'm not happy with it. I guess I just expect too much out of stock 38's.

 

[Foximus]

you dont give 38s enough credit....

 

[Matt_E]

I concur. 38's may not get the most out of a bigger motor, but they do not run "crappy" when tuned right.

 

[Mike W]

I concur. 38's may not get the most out of a bigger motor, but they do not run "crappy" when tuned right.

Well, thats what I'm trying to do. Don't get me wrong, it does rip and runs good, it just runs muddy in the low speed circuit no matter what adjustments I make.

 

[Matt_E]

What is the measured popoff pressure?
Are the carbs synchronized?
Are the needles clean and not worn out?

 

[Mike W]

What is the measured popoff pressure?
Are the carbs synchronized?
Are the needles clean and not worn out?

What is the measured popoff pressure? 55psi
Are the carbs synchronized? As far as I can tell. The butterflies look even.
Are the needles clean and not worn out? They are brand new. I just replaced them

 

[Matt_E]

You're running a pipe, right?
How many screens on the flame arrestor setup?
Are the reeds in good condition?

 

[Mike W]

Ive been thru all this troubleshooting with Chuck (Supertune) already. I think they are not synchronized properly or something else I overlooked.

 

[Matt_E]

Shoot, why didn't you say so? :biggthumpup:

If Chuck can't help you, then I won't be able to for sure.

 

[Foximus]

Set the pop off to 30 psi. try 75 and 130-135. That should give you a boost.

 

[Matt_E]

Worth a try, but I would probably change either pilot or popoff, not both - as the lower popoff will increase fuel flow at lower RPMs, and the bigger pilot will do that as well.
You may ultimately end there, but do one thing at a time.

 

[Foximus]

good call.

 

[Mike W]

Shoot, why didn't you say so? :biggthumpup:

If Chuck can't help you, then I won't be able to for sure.

He is doing his best to help me out but I'm just a carb tard.