Results 1 to 10 of 10
  1. #1
    SJ-(KY)'s Avatar
    Join Date
    Jul 2007
    Location
    Forest Hills,KY
    Posts
    278
    +1
    4

    Very strange knocking problem.....03 gpr1300..

    Just got another GPR together and this one has me on edge. Well to make a long story short traded my friend my running ultra150 for his hurt gpr. What happend was his oil pump took a dive and hurt #1 cylinder/Piston. I got the cylinder fixed and got a new piston and rings and got rid of the oil injection with the block off plate. Got my first tank of gas mixed at 36:1 and started it up with no issues other than it sounds like it has some type of a knock. I pulled the plugs and turn it over and it sounds fine with no knock! I pulled the head and nothing out of the way everything looks happy etc etc... What am i missing here? Any suggestions?


  2. #2
    banshee350racer's Avatar
    Join Date
    Oct 2008
    Location
    Mokena,IL
    Posts
    170
    +1
    1
    if it sounds like this

    its the nature of the beast i thought the same thing when i first built mine

  3. #3
    powerstroke specialist mikegp's Avatar
    Join Date
    Mar 2011
    Posts
    2,529
    +1
    190
    if you have wear on the intermediate splines and the drive shaft it will make a funny noise at idle.

  4. #4
    SJ-(KY)'s Avatar
    Join Date
    Jul 2007
    Location
    Forest Hills,KY
    Posts
    278
    +1
    4
    I dunno fellas im starting to think when my friend siezed that #1 cylinder it may have hurt the crank. I went back out and put the head back on to listen again and its knocking pretty hard. Its just weird that it only knocks when its running with the plugs in. When i turn it over with the plugs out it sounds fine.

  5. #5
    powerstroke specialist mikegp's Avatar
    Join Date
    Mar 2011
    Posts
    2,529
    +1
    190
    remove the head take that cylinder out and inspect the crank.

  6. #6
    Had this happen to a friend. Crank rod bearings went. You could pull the crank rod up and down 1/8th of an inch of play. On his it did do head and cylinder damage in the process. He caught it early enough that it didnt take all cylinders out with it, just two.

  7. #7
    SJ-(KY)'s Avatar
    Join Date
    Jul 2007
    Location
    Forest Hills,KY
    Posts
    278
    +1
    4
    Do any of you guys think if the roller bearing that slides over the wrist pin was bad it might cause a knocking sound? Or better yet i put a sbt piston back in the cylinder and it said DO NOT use the two shims that go on each side of the wrist pin. Could that be it?

  8. #8
    silvercrxsir's Avatar
    Join Date
    Sep 2011
    Location
    ocala,fl
    Posts
    334
    +1
    8
    Have you double checked the piston to cylinder clearance,mine had a knocking sound and it turned out to be excessive clearance,I took the piston and cyl to machine shop to measure it since they knew what they were doin,another sign of piston slap is slight scoring in the cylinders and the piston skirts will be nicked up.I'm not familiar with the 1300, is it a nikasil cyl or a sleeved cyl,and was it bored oversized

  9. #9
    SJ-(KY)'s Avatar
    Join Date
    Jul 2007
    Location
    Forest Hills,KY
    Posts
    278
    +1
    4
    My cylinder walls looked perfect when i pulled the head back off...

  10. #10
    A child of five would understand this. Go get one. pierowman's Avatar
    Join Date
    Sep 2011
    Location
    Seattle, WA
    Posts
    280
    +1
    7
    What are the numbers from the compressions test? Also have you preformed a leak-down test?

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Very Strange! New Yamaha Jetski 2009
    By branix in forum Videos & Pictures
    Replies: 6
    Last Post: 09-12-2007, 04:47 PM
  2. 2000 Virage strange starting problem
    By bclake in forum Polaris How To & FAQs
    Replies: 2
    Last Post: 09-08-2007, 04:13 PM
  3. Very strange running issie...
    By lt1transam in forum 2-Stroke Performance
    Replies: 10
    Last Post: 06-20-2007, 07:03 AM
  4. Lost Power on '03 GPR1300...HELP!
    By handybuilder in forum Yamaha PWC Performance (2-stroke)
    Replies: 12
    Last Post: 06-10-2007, 07:49 PM
  5. Strange electrical problem -- instrument cluster going crazy
    By NateGP1300R in forum Yamaha PWC Performance (2-stroke)
    Replies: 4
    Last Post: 07-06-2006, 05:23 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •