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  1. #1
    Phil's Avatar
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    Still running bad - tried everything!

    Where did my ballistic acceleration go? We have tried everything to get my RR Stage III GTX back to the way it was, but nothing seems to be wrong with the engine. I have 170 hours on the engine, but:
    . Did a leak down test and it showed only 2% leakdown. That's nearly perfect!
    . All cylinders read 118 lbs. of compression.
    . The ATM boost guage reads 7.5 lbs.
    . The fuel pressure is 60 lbs.
    . We changed the plugs and they appear to be burning perfectly.
    . There are no leaks in the hoses or delamination in the exhaust hose.
    . The cam timing is set correctly.
    . The new RR SC clutch is set to 110 per Mark U.
    . The prop is perfect (no dings, bends etc.)
    . We changed the knock sensor.
    . We changed the carbon seal.
    I am thinking that 7.5 lbs.of boost may not be enough? Has this happened to anybody else?


  2. #2
    Phil's Avatar
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    Ooooops, I forgot to mention that my RPMs are now 8,000. But they used to be 8,500!

  3. #3
    Sunfunzoom's Avatar
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    Did you try disconnecting the battery for a while and reconnecting it? Just a shot.

  4. #4
    Site Admin Green Hulk's Avatar
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    Phil, looks like you have been over everything. The only thing i can think of is the intercooler. You run in salt water don't you?
    Do you run a strainer on your waterline going to your intercooler?
    If not the intercooler could be clogged with all kinds of debris making it less efficient.

    Just some food for thought!

  5. #5
    Moderator two2curupt's Avatar
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    Phil give me a call..Or drop me an e-mail..

  6. #6
    Phil's Avatar
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    Quote Originally Posted by Green Hulk
    Phil, looks like you have been over everything. The only thing i can think of is the intercooler. You run in salt water don't you?
    Do you run a strainer on your waterline going to your intercooler?
    If not the intercooler could be clogged with all kinds of debris making it less efficient.

    Just some food for thought!
    Nope, I run in fresh water. Let's say it could have gotten clogged, how do you clean it?

  7. #7
    way2fast's Avatar
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    Try to reverse flush it or bring it to a radiator shop and see what they come up with......or get one from Riva. They seem to work better anyway.

    Richard

  8. #8
    Site Admin Green Hulk's Avatar
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    I don't know about the Riva intercoolers working better. The fastest RXP's in the world are running Rotax Racing intercoolers.

    I would love to back to back test a Riva intercooler. Hopefully I will get that chance very soon. Until then, I would never say they work better.

    It may "seem" that the Riva intercooler works better because there are a select few guys up in Michigan running in cold ass 70 degree water with the Riva stage 2 kit running exceptional speeds. Everyone else down south in 90+ degree water is running 72-73 with that kit.

  9. #9
    Moderator two2curupt's Avatar
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    Can we have a shoot out pls....Stage 2 Rotax kit against a Stage 2 Riva kit...Then we can end this talk....
    I would even challenge a stage 2 riva RXP on my Rotax stage 2.5 GTX..

  10. #10
    Quote Originally Posted by Green Hulk
    I don't know about the Riva intercoolers working better. The fastest RXP's in the world are running Rotax Racing intercoolers.

    I would love to back to back test a Riva intercooler. Hopefully I will get that chance very soon. Until then, I would never say they work better.

    It may "seem" that the Riva intercooler works better because there are a select few guys up in Michigan running in cold ass 70 degree water with the Riva stage 2 kit running exceptional speeds. Everyone else down south in 90+ degree water is running 72-73 with that kit.
    When is Nils intercooler going to be out or is it delayed because of his SC work.

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