Carb Pop-Off setting

[etemplet]

Since I will begin tweaking the jet skis I am curious about the carb pop-off settings. My SPI is down at the bottom of the range but within range at 23-24 psi. The ski runs good and smoothly transitions between throttle settings. I am not looking to change anything just to understand. If thy setting was in the middle of the range at 30 psi... what differences would be noticed? I will also check the carbs on both GTXs to make sure the settings are where they need to be. I am considering getting an exhaust gas analyzer type tool.

Where can I purchase a range of springs for setting the pop-off? I read about them in the Pinned Carb thread. I would like to have some easy options. I really didn't have any luck bending the tab and was uncomfortable doing that.

 

[mikidymac]

The springs are a big range and will probably put you outside of the stock range. Bending the tab 1-2mm up or down is perfectly acceptable for fine tuning. In general a higher pressure spring will lean out a little bit and a lower will richen up a bit. It also depends on the needle and seat size.
For a stock ski there is no reason to change the spring weight or needle and seat size. As long as you are in the factory range everything will be fine. Changing the pop off a few psi will give you no noticable change in performance.

Also keep in mind pop off is just a test and isn't how the carb functions when actually running as it is vacuum operating the diaphragm that opens the needle and not fuel pressure like when testing pop-off.

 

[etemplet]

I did bend the tab a bit downward because I wanted to get a little bit away from rock bottom on the pop off pressure. It wan't much, not even a MM but I didn't like bending it at all.