Results 1 to 5 of 5
  1. #1

    Found a set of Prox pistons for the 1100 STX-Di 2002( but something is differnet)

    The prox pistons 01.4514.50 is flat across the top. The OEM piston have a circular dish in the top of the piston which I thought might be unique for the for the injector. I cannot find any information that says the dish is specific to the DI model or is even impoertant. I would think the Pro-x pistons which are build for OEM spec. would work. Now I am concerned about the difference I see in the two pistons?

    Has anyone replaced their 1100 STX Di piston and notied aftermaket not havng the cut out dish on top of the piston?

  2. #2
    The dish was used to help atomize the fuel. Here is an article on the engine.

  3. #3

    returning PROX Pistons ( so I am down to SBT of WSM as a choice for the pistons

    Called SBT today and they have the pistons which have the circular disk impression on top of the piston for the DI , also spoke with WSm and there piston for the 1100 STX Di also has the circular disk impression on top of piston. I have not seen any good write ups on these psitons, but had to pay the cost of pulling a new OEM set of pistons from Kawaski.

    Any other recommendations on SBT or WSM or a 3rd choice piston. Also recommendation of a Good PWC company that bores out cylinders?

  4. #4
    Ive got 2 summers on my WSM pistons now and no problems. Im not sure the factory pistons are any better than the WSM. The factory are simply cast pistons and my engine failure was from a factory piston that disintegrated in the bore.

  5. #5
    I am doing the piston top end rebuild because of two issues.
    1. I have 250 plus hours on the jetski
    2. The plugs are getting a black oily look on them
    3. The number three piston was missing from fouling

    I had the cylinder measured and it was showing different wear measurements

    Thought this would give it some new life, as I have enjoyed the ski.

    This ski sounds like an old Harley when idoling, and tends to vibrate until you start to give it gas. But has always been reliable.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. WTB - Parts prox piston for gp1200r
    By bajaeater in forum Yamaha Classifieds
    Replies: 1
    Last Post: 07-19-2012, 08:55 PM
  2. New Wiseco Pistons for the 4-Tec Engines
    By 800AMSOIL4U in forum 4-Tec Performance
    Replies: 26
    Last Post: 06-18-2011, 02:47 AM
  3. WTB GP1300 cylinder or set of ported cylinders for the right price.
    By slydogge in forum Yamaha Classifieds
    Replies: 9
    Last Post: 03-01-2011, 10:39 PM
  4. ProX Pistons for 1300
    By JKR1300 in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 05-05-2010, 11:27 AM
  5. The correct piston for the correct cylinder???
    By WAGZ102 in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 01-05-2008, 06:56 PM

Posting Permissions

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