Page 1 of 4 123 ... LastLast
Results 1 to 10 of 40
  1. #1

    2003 gp1300r TOPS SPEED 55-56 MPH GPS ..Guage read 60

    Seems like this is about 10 MPH slower that what it should be doing factory isnt it?

    Still pretty fast i guess.

    Wouldn't mind to pick up a few MPH..

    This was using Yamalube 2W.

    I will be mixing the KLOTZ R50 OIl at 40:1 for the next run. .

    Only mods is the block off and cat delete

    Everything else seems to be stock.



  2. #2
    powerstroke specialist mikegp's Avatar
    Join Date
    Mar 2011
    Posts
    2,544
    +1
    194
    first , the speedo is a joke ,its never accurate so dont go by that. 55 is way to low for that ski , maybe prop took a crap ,inspect your pump.
    second , do the basic , check compression , make sure the valves are opening, the should cycle when bump the start switch or turn off the engine.
    last, different oil is not going to make the ski any faster ..

  3. #3
    Prism's Avatar
    Join Date
    May 2007
    Location
    "New" Jersey
    Posts
    826
    +1
    100
    Look at the pump shoe on that year ski. They were known to pull down and ripping the mounting inserts through the pump tunnel. Even if it isn't leaking and has been fixed by someone, be sure it was done correctly and isn't hanging low. The pump shoe should be recessed into the hull a bit. A hanging shoe will scrub lots of speed. As mentioned, check the clearence between the wear ring and prop, look for dings in the trailing edge of the impeller and make sure the powervalves are working and adjusted properly. Also get baseline compression readings. Let us know what you find.

  4. #4
    I will check compression this afternoon.

  5. #5
    What is the optimal compression per cylinder? I may pick up a set of plugs as well. What is recommended plug to put back in? Could me running a 32-34:1 ratio be a issue ? I used a Quart of 2w and only was able to add 8.6 gallons of fuel

  6. #6
    Prism's Avatar
    Join Date
    May 2007
    Location
    "New" Jersey
    Posts
    826
    +1
    100
    The yamaha shop manual lists any reading indicating 91psi or less as needing investigation and repair. In my experience, most stock 1300R engines achieve between 110 and 118lbs of compression. Things like the gauge and your altitude can effect readings. Sparkplugs are NGK BR8ES-11.
    As for premix. Most people run 40:1 for easy calculation during mixing. GroupK did a study and found the most power and protection from mixtures of about 32:1 to 36:1.

  7. #7
    powerstroke specialist mikegp's Avatar
    Join Date
    Mar 2011
    Posts
    2,544
    +1
    194
    every 1300r that i have got in good condition had a compression reading around 130 , using a snap-on gauge. lol .

  8. #8
    Compression holding 100 across all cylinders….
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	image.jpg 
Views:	45 
Size:	77.6 KB 
ID:	365219  

  9. #9
    How are you doing the test?

  10. #10
    Quote Originally Posted by Robfromga View Post
    How are you doing the test?
    pulled one plug at a time and screw the compression fitting and turned over for about three seconds and let it sit for about three hours and the pressure never dropped

Page 1 of 4 123 ... LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Wake Pro 215, 2009 - top speed 64.9 mph on GPS
    By R12Xer in forum 4-Tec Performance
    Replies: 2
    Last Post: 04-12-2014, 07:22 PM
  2. 2003 Seadoo GTX SC REVS AT 6500 TO 6650 but top speed only 42 mph
    By gp1200nseadoogtx in forum Sea Doo Open Discussion
    Replies: 1
    Last Post: 06-02-2011, 09:25 PM
  3. New Top Speed!!! 73.3 on GPS
    By somefun in forum Sea Doo Sport Boats
    Replies: 19
    Last Post: 11-29-2007, 04:21 PM
  4. 07 gp1300r top speed (stock)
    By james k in forum Yamaha PWC Performance (2-stroke)
    Replies: 11
    Last Post: 08-12-2007, 11:19 AM
  5. 2003 XLT1200 Top Speed
    By Mizelra in forum Yamaha Open Discussion
    Replies: 8
    Last Post: 01-09-2007, 12:03 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
  •