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  1. #1
    Luis Marine's Avatar
    Join Date
    Oct 2007
    Puerto Rico Drag island

    GPR 800/1200/1300 Triple exhaust ports/Big bore Cylinders

    This sleve's are new you need to bore to your piston size $500.00
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  2. #2
    Just wondering if you are still doing these triple exhaust port cylinders. Looking for a set for my GPR

  3. #3
    Any one test that cylinder?
    Where I can buy that sleeve?

  4. #4
    If you pm him I think that he has two for sale, $250 each and you bore to size. I was gonna get them but I wanted 3 for a gpr. I spoke to lowell horning about them and this was his reply .

    Lowell said -

    "No I have not seenthis on a GPR. The cylinder is sleeved – I don’t know if it is a 66E / 800 or something else Yami made. I know both Polaris and SeaDoo /SkiDoo used their snowmobile cylinders – which are triple exh. port – on the watercraft. Most of these were low runs for racing / closed course years ago. Some sled / snowmobile owners bought the watercraft bottom ends to put sled cylinders & pipes on to make open class sleds.

    It is not feasible for me to put the aux. exh. ports in. I have done it on sled engines – one (3 cyl. unibloc) was the last.

    For the triple exh. port to be effective you need the triple pipe, or possible a twin engine to use the compression a triple exh. will run. RPM is the other consideration. All your small bikes run the triple exh. for both compression and RPM.

    I think you will find what others have found. Triple exh. will survive with lots of maintenance for Closed Course racing. Rec riding where you can hold WOT for minutes will cause heating and jetting problems to keep it running right.



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