Superjet - Pop Off pressures

[Superjetron]

I have recently rebuilt my Superjet (Top End and Carbs) but now having problems with Carb settings. I have 38 super BN's,factory B,Carbon Reeds and stuffer, Carb spacer. So far I have tried different springs and 1.5 needle and seats but still seems to bog down. I even put back old needles and seats which ran fine before but still does not run right. Can anyone recommend anything ? do I need to go to 2mm needles and seats ? or could I have an air leak ?

so far I have tried 1.5 needles and seats with all springs. The shinny silver spring was best but still did have a lean hesitation.

Any clues would be great. thanks :splatt:

 

[felix5oh]

When i bought my Superjet it had an awful bog when you chopped the throttle when aproaching a wave. I changed the low speed jets many times and though it improved, it still wasn't right. It would stall and had no mid range.



Finally, i went from a 95g spring to a 80g spring and now it jumps out of the water.

 

[Watty]

A 1.5 N/S is fine. Get a gauge and test the popoff in both as I'll pretty much guarantee that both of them are different, and they don't correspond with the popoff chart from Mikuni.

If you are changing out the springs and it's not making any difference, I would look elsewhere. Write down your low speed settings and then start playing with them to see if it gets better or worse. Throw a meter between you plug boots and check for high resistance or fluctuating readings when you wiggle the wires. Check your reeds for holes/chips, make sure you don't have any fuel blocks anywhere, clean carbs and filters.

 

[Superjetron]

The carbs have been rebuilt and I have new filters. I have gone down to the shinny silver spring giving me pop off of around 30 but still getting lean hesitation. The pulse also feels ok and is pulsing.
I am going to try black springs with 2m needles and seats to see if this helps.
Low speed settings are set at 1 1/4 as recommended by Factory pipe.
Dont think I got a fuel blockage as tick over and top end its not as bad.
would the carb spacer be affecting anything ?

 

[Watty]

Well if you are getting a lean hesitation and your popoff isn't getting rid of it, you'll have to play with the LS jet and adjuster. Read the Mikuni tuning guide and it will tell you everything you need to know.