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  1. #1

    03 Freedom Pop off pressure

    I am have some continuing issues with my fuel system in my 03 freedom. I have a new motor, plugs, fuel line, selector valve, fuel pickup, spark plugs, and reeds installed and carburetor is rebuilt. Before I rebuilt the carb the pop off pressure was 26-28 PSI. It would run good everywhere except idle to 1/4 throttle. I set everything in the carb back to factory specs, including pop off pressure to about 20 PSI (manual said 18-21 PSI). It runs very strong now in the mid and top end. Still has issues with what sounds like a light, fast miss and vibration at low speed throttle settings. John Zigler said he thought the manual might be wrong on the pop off settings but he wasn't sure at the moment on what it was. I was thinking about going the other direction and putting a longer spring in it. I cannot seem to tune this out with the low speed screw, so I have it set at factory setting of 1-3/4 out. If it means anything, I was still on the 32 to 1 break in mixture on my last ride, but I figured that is not the issue. Thanks.


  2. #2
    Also, I was just doing some research on here and read a post by K447 that mentioned the major "whoosh" from the fuel tank if the cap is removed....mine does that. I checked that vent valve once and it seemed to release at the 1-2 PSI but I definitely get a lot of pressure built up. My buddy even mentioned that it was kind of ridiculous when he took the cap off and thought it seemed abnormal. Think this might be the problem?

  3. #3
    Click avatar for tech links/info, donation request K447's Avatar
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    Quote Originally Posted by 07keo02 View Post
    Also, I was just doing some research on here and read a post by K447 that mentioned the major "whoosh" from the fuel tank if the cap is removed....mine does that. I checked that vent valve once and it seemed to release at the 1-2 PSI but I definitely get a lot of pressure built up. My buddy even mentioned that it was kind of ridiculous when he took the cap off and thought it seemed abnormal. Think this might be the problem?
    So replace the vent check valve.

  4. #4
    Okay, do you think it can test okay but for some crazy reason over pressure the tank? Or is there anything else that might cause a pressure issue? Not trying to ask stupid questions or anything but I have really tried to do my homework and replaced a bunch of stuff and just can't seem to get it quite right.

  5. #5
    It's pretty hot out so I went outside and pulled off the gas cap and very minimal pressure came out. I was going to change the plugs out now that I am moving on to 40-1 mixture. The darker plug is the mag cylinder. I am thinking maybe I have weak spark at low RPM? Nevermind the picture of the steel braided line, I selected the wrong photo and wasn't sure how to remove it. I will order the vent valve.
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  6. #6
    Click avatar for tech links/info, donation request K447's Avatar
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    Quote Originally Posted by 07keo02 View Post
    Okay, do you think it can test okay but for some crazy reason over pressure the tank?

    Or is there anything else that might cause a pressure issue?

    Not trying to ask stupid questions or anything but I have really tried to do my homework and replaced a bunch of stuff and just can't seem to get it quite right.
    If the venting hose is kinked, blocked or collapsed then the vent cannot actually vent.

    The check valve is not expensive to replace.

    It is hard to accurately test the release pressure of the check valve, so how does one determine whether it is partially sticking or has some other issue?

    The original check valve is at least ten years old.

  7. #7
    Any other ideas on the rich condition? Venting the tank before riding seems to make no difference. Don't know how accurate my pop off pressure gague was either.

  8. #8
    Just ordered a new vent valve and decided to replace the low speed screw since it's about the only thing I didn't do in the carb rebuild. I also put the largest pop off pressure spring in and will update this weekend.

  9. #9
    Replaced the vent valve and low speed screw with no change. The longest pop off spring made it lean bog as I suspected. The ski is running perfect from mid range to WOT. I cannot, for the life of me, figure out what the problem is from idle up to mid range. It is also hard for me to determine if it is lean or rich. Today it was doing OKAY at 1 3/4 out, 20 PSI pop off but as I started to mess with the low speed screw it all went down hill. Even when I changed it back to 1 3/4 it would die at low speed throttle manipulation. I thought this might be lean but if I pull the plugs after idling they are very wet with fuel. Manual calls for 18-21 PSI pop off but SBT told me three different number ranges from 3 different people. One said 26 was too high, another said 20-25 and the last said 18 is pushing it. I don't know what else to do.

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