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  1. #1

    GPR owner's, suprise, cowling blocked-off!

    Jeese, I guess I gotta get the dremel out! I swiss cheesed the bucket/cowling last year and I ASSUMED that the right side of the cowling was open. My beef is that I wonder how the right-side ducting/trunk-line ever got air in stock form? No wonder why the seat used to suck air....

  2. #2
    mrbtd's Avatar
    Join Date
    Jul 2005
    Lindenhurst, Illinois, United States
    before you get your dremel out spend 5 minutes on the ski with the seat off and see if the extra air makes a RPM difference.

    I have done it several times when i was still a 2 stroke and it didnt make a lick of difference.

  3. #3


    ...good point mr... It would certainly be nice to get a bit more top-end especially since the design of the hood is such that it lends itself to the 70's muscle car type ram-air effect. My issue is that when I went to the race filter and bucket cheese, the seat didn't suck air quite as much, and so I also figured the black blanking plates under the side cowling venturies were there to be removed by racer's. Afterall ,the right-side open duct lines don't serve much of a purpose otherwise, no?

    RPM's will indeed be the tale tale, but also if I get more responsiveness from low to midrange, it's worth doing, yes?

  4. #4

    Join Date
    Aug 2008
    u can cut it out with a utility knife (new blade of course) heating the blade makes it that much easier, dremel may be a bit much, as for gains, can't say it did a thing but feel better knowing more air is in there

  5. #5
    Nothin' runs like a Deere IowanGPR's Avatar
    Join Date
    Sep 2006
    Waterloo, IA
    Quote Originally Posted by jim mcgreehan View Post
    It would certainly be nice to get a bit more top-end especially since the design of the hood is such that it lends itself to the 70's muscle car type ram-air effect.

    you missed the point. 70's muscle car is still not a 2 stroke.

    take out the stock intake pipes inside. if you get porting/bb/sonic booms then you should start worrying about getting more air. the bucket/hood mod is all i have done and i'm doing just fine. next i will do the seat air mod if i think i need it. but the cowls-to me- are a waste of time.

  6. #6



    1. Doesn't more air flow increase the likelihood of more fuel/air mixture viz. the venturi effect?

    2. Why do the seats on the stock gpr's suck air?

    3. Why is there a difference in air flow theory between a 2 and 4 stroke; isn't adding more flow to the motor beneficial in either case?

    Sorry for all the questions.

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