1995 Rotax 717 Carb Popoff Pressure - what should it be?

[orbit398]

So I have look on the site for what the popoff pressure should be but haven't really found I should try to obtain. The new Needle Valve assembly I have is a 1.2. Per my Mikuni manual (attached), on page 15, it shows the smallest is 1.5. I bought Mikuni rebuild kits and Needle Valves from a local shop and asked him today about having only a 1.2. Guy has been in business for over 30 years and said this was a change long ago and the ones in the carbs now are 1.2 as well. In the rebuild kit, there are three springs for the arm. I have the ones in the carbs and about 15 more springs in the box of carb stuff I got with the waverunner.

Anyway, for the carb rebuild, what roughly is the popoff psi range the carbs need to be at? What I show now on the two carbs is about 40 to 45psi. If this a little high, I can play with springs to get it down but just wondering what folks think the ideal psi should be. Carbs have stock jets and airbox stuff, cylinder compress is above 140psi for each.

thanks

 

[mikidymac]

What model ski do you have.
No, you don't just start messing with springs to get the psi.

 

[orbit398]

1995 XP with 717. Per a guy on greenhulk, he states 35-37psi is ideal. So these two carbs have the 65 gram springs in them. And I am getting 42psi as the popoff as best I can tell. Just for grins, I put the 95 gram springs in and popoff was about 58 to 60 psi, so put the 65 gram spring back in.

 

[mikidymac]

1995 XP should have 1.2 needles and seats with 80 gram black springs. these springs do not come in the kits.

 

[orbit398]

ok - thanks. The 80 gram springs are the ones I don't have a bunch of from the PO. Do you know what kind of psi the 80 gram springs will yield?

So I see you have an HX. I picked up one of those too along with this XP. Did rebuild on that one too and have a question you might know something to look for. See this link 1995 HX 717 motor question
thanks

 

[mikidymac]

40-56 psi but don't get hung op on the pop-off psi, it is just a test, not a target to start swapping out parts.
Sea Doo PWC Carburetor Reference