Page 1 of 9 1 2 3 ... LastLast
Results 1 to 10 of 85
  1. #1

    Join Date
    Feb 2012
    Location
    Mackay Qld Australia
    Posts
    90

    Smile Seadoo gtx di - 2002

    Hi All, new to the Jetski world, always been into dirt bikes.

    Anyhow, good sister gave me a Jetski which they acquired for cheap when someone needed the money bad.

    It is the ever wonderful GTX DI - with a couple of problems!

    First things I found wrong was the pump was completely screwed, a bar out of the grate had snapped on gone through the pump - whole thing was done for. Anyhow I scored a used pump from correct model etc and serviced bearings etc. All good

    Time for first ride - was bascially a shakedown ride and I certainly wasnt expecting any miracles of goodness. I wanted to find it what - if anything needed attention and go from there. When running ski in back yard with water hose connected for cooling it has always started instantly and run perfect.


    So we hit the water, max performance of 25mph, plenty misfiring and power was low. Pump seems to work well with no oil leaks. Would pull for a bit then die out pretty much, not stalling but just fade away.

    So it was head for home and start changing things etc, new correct number spark plugs, drained every last ml of fuel and refilled with fresh, pulled both rave valves out and cleaned them properly, then headed to freshwater dam for take 2. This time we were up to 35mph - but still with an intermittant miss right off idle, it sort of comes and goes but seems to contribute to low engine performance once the rpm climb. We gained 10mph but needing another 20 yet.

    The max attainable rpm is 5900 rpm, engine temp of 87F, speed around 34mph.

    The front spark plug is white clean (too lean) when the rear plug (nearest the jet) is about perfect for colour.

    Now I have read endlessly where people have completely overhauled the injection system and parts thereof trying to cure this exact (or near to) same problem. Often it has been found that an ignition coil has gone bad but not in a total sense. I have inspected the spark on both cylinders and oddly enough while both seem to be pumping out strong sparks I believe the sparking at this same front plug is slightly variable to the eye.

    Interestingly enough when yard testing it will run fine on either cylinder if other cylinder has plug lead disconnected from sparkplug (with lead connected provided spark post)

    What is max operational RPM for this craft?

    Any ideas?


  2. #2

    Join Date
    Mar 2006
    Posts
    1,282
    +1
    52
    your ski should run 6800 +/- 100 or so RPM w/ a good stock impeller.

    Does maintance show up on the dash info center?

  3. #3

    Join Date
    Feb 2012
    Location
    Mackay Qld Australia
    Posts
    90
    OK, injectors are in for cleaning and checking today

    I also found a lot of moisture in the coil box, so lid has been removed and is being dried out, no corrosion and all plug lead connections appear water tight. The reddish spark could be explained by this situation tho.

    I will see what difference the 2 above items make and take it from there, will report back


    Jim, TBH I didnt see such a message however I will reconnect the battery and double check
    Last edited by Tradewind; 02-17-2012 at 04:21 AM.

  4. #4

    Join Date
    Feb 2012
    Location
    Mackay Qld Australia
    Posts
    90

    Cool Update

    I have now cleaned the injectors, no change in the way the engine runs out of the water but now I have my ear tuned in a bit better to this engine I can pick up the intermittant miss without being in the water.

    The miss is there exactly the same as previously, its now time to focus on the coils, I will buy a new one and see what change that makes and it gives me one that is known to be perfect which I can swap between the 2 cylinders and see if I can shift the miss from one cylinder to the other in the second instance, in first instance replace the coil firing the cylinder which isnt performing well

    There is no MAINT message on dash - all ok there

    Onc step at a time we get there

  5. #5

    Join Date
    Feb 2012
    Location
    Mackay Qld Australia
    Posts
    90
    OK next update, I purchase another coil for the front cylinder - no improvement, still a miss and uneven run at idle. It will run fine on this cylinder alone but a bit uneven, wereas the rear cylinder runs much smoother all the time

    I guess its down to the air injector now - any other suggestions people??

  6. #6

    Join Date
    Feb 2008
    Location
    Puerto Rico
    Posts
    290
    +1
    4
    Welcome to the forum. DI engines onces tuned right are very reliable and fuel economic.

    With that been told I suggest to make a full check up. You will need a FUEL PRESSURE GAUGE and make a water test to measure if you are having a loss while riding. When testing I usually try to feel the temperature on each cylinder to see if they are working. If one is cooler there might be a problem. That comes to the other test. COMPRESSION . You should be around 125 psi over if not start opening the engine.This particular engine being a direct injection type tend to create moisture on the air injectors and the compressor. You can remove the air line and turn the engine to see if there is any residue of sludge or moisture inside. The compressor has a like a top head with a paper gasket, inside there is a litle diaphragm that when it brakes can give troubles like that. Also get a multimeter and check your charging system. This DI's if not charging well can get a limp mode. Thats all I can remember for now.

    Hope this helps. And feel free to ask because here on the forum you will get great advice from guys that work with them all the time.

    Cheers.

  7. #7

    Join Date
    Feb 2012
    Location
    Mackay Qld Australia
    Posts
    90
    OK here we go, I had a few more minutes to check on the machine in between everything else

    The voltage at the battery when running is around 13.97v - 13.99v and stable. At rest the battery is a solid 13.3volt (new battery)

    The rpm at idle on the front cylinder (nearest the steering) only is 1440rpm but a bit unstable

    The rpm at idle on the rear cylinder (nearest the pump) only is 1440rpm also but very stable

    Next test was full throttle on one cylinder at a time only to see what run quality was like

    Front cylinder only - unable to hold any rpm above 4800 with rapid accel/decel, complete cutting out and detonation all part of the show. This was like a 1-2 second at WOT

    Rear cylinder only - 6500rpm and pretty smooth. This was like a 1-2 second at WOT

    I also removed a RAVE valve cap/spring and give it a quick rev to above 4000rpm and the RAVE opened instantly on the front cylinder, operating smoothly and freely on rear cylinder also. All good there

    I can do a compression test later, fuel pressure testing a bit more of a challenge.

    Its likely to be coming down to an air injector or fuel injector fault on the front cylinder at this stage. Although the injector was ultrasonically cleaned they didnt have the apparatus to flow check it. I have read recently that you have to confirm the flow test or the injector can still be bad.

    Another test I could do is swap front fuel injector to the rear and perform the same 1 cylinder power tests which provides load due to the pumping of the other cylinder

  8. #8

    Join Date
    Feb 2012
    Location
    Mackay Qld Australia
    Posts
    90
    Next update

    The cylinder compression has been tested with a very solid 130psi on both cylinders - precisely!

    Now to fuel pressure and swapping fuel injectors

    What sort of fault do air injectors give?

    The now and again detonation detected today is a clear indication of lean fuelling on the front cylinder, that is the logic driving me to a fault at the fuel side now

  9. #9

    Join Date
    Feb 2012
    Location
    Mackay Qld Australia
    Posts
    90
    Next update 2

    I have swapped the front fuel injector to the rear and performed the above tests - with exactly the same results! The front cylinder misses and detonates, runs fine for a few thousand revs etc as exactly as it did before

    We have to now have a dud air injector - its the only part I have not done anything with or cross tested

    OK - first

    How do I keep moisture out of the air system

    Where in the world does the compressor intake its air from - cant see it anywhere

    I can source some DI air injectors if I recall so will get onto that supply on Monday

    Other opinions welcome

  10. #10
    Just FYI, the air injectors is usually the ones that goes bad, not the fuel injectors. (they are under a lot of heat stress...) Try swapping out the air injectors and see what you get. (I know, it is a pain as you need to remove the fuel rail...)

Page 1 of 9 1 2 3 ... LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 2002 Seadoo GTX towing
    By jplageman in forum 4-Tec Performance
    Replies: 0
    Last Post: 08-20-2011, 11:58 AM
  2. 2002 Seadoo GTX Issue
    By Steeda95 in forum Sea Doo Open Discussion
    Replies: 4
    Last Post: 04-12-2011, 07:07 PM
  3. FS 2002 Seadoo GTX N/A 155
    By cmher18 in forum Sea Doo Classifieds
    Replies: 0
    Last Post: 04-04-2010, 08:52 PM
  4. WTB 2000-2002 seadoo gtx mpem
    By nick34 in forum Sea Doo Classifieds
    Replies: 3
    Last Post: 02-25-2010, 09:36 PM
  5. Seadoo GTX 4 Tec 2002
    By landew in forum 4-Tec Performance
    Replies: 4
    Last Post: 06-02-2009, 09:30 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
  •