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  1. #1

    1998 Porpoising Problem , Need Advice !

    Hi Guys,

    I am looking to solve a handling problem on my1998 GP 800. From what I have read up on it looks like it is a common issuewith this machine. I believe the problem is known as porpoising. Basically itfeels like a bucking bronco. Itís tough to get a smooth ride even under mildconditions.

    Question #1 - My first plan is to add 3 washers to the rideplate. Do I have the correct position ?

    Question #2 - To help with this issue should I adjust the trim tabs down ?

    Question #3 - I read that replacing the ride plat with a stockride plate from a 1200 would help solve this issue because it was longer. What year ride plate would be a direct bolt on and from what machine ?
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    Last edited by stanleydan; 07-20-2015 at 08:19 AM.


  2. #2
    The problem is actually porpoising. It is a common problem. Search porpoising and GP you will find lots of help. I think the 99 gp1200 also had this problem. Also the "Trim tabs" you are referring to in the picture are actually called sponsons. Some people say it helps when lowered. You will want the gp1200 1997 ride plate which is longer. not sure if the 98 works but just make sure it is longer than yours. Then you can shim the rear bolt a couple of washers and test. Do remember the more you shim that back bolt the more you will loose speed.

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