Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 30
  1. #1

    2000 Yamaha GP1200 , Idle setting

    Hello , i have a big question. So after my restoration project on my 1200cc engine i hade finally gathered the balls to try and go out this week to test the ski on the water. All i want to know is how to increase my idle in the ski? On my last post some guy said that my idle was way to low and that my engine with stall out on the water. Currently its set at 1500-2000 rpm. So im thinking of bringing it up to 2400-3000 rpm at idle. Now i know that there is a idle adjustment screw at the engine and i have adjusted it to the point where i cant screw that long screw with the spring anymore. It can go in more but it just does not want to. So does this mean i need to adjust all 3 of my carbs? I need advice on what to check for a first time launch. Also should i stay at 40:1 mix ratio or should i go to 50:1??? Thank you


  2. #2
    Echo's Avatar
    Join Date
    Aug 2013
    Location
    Tarpon Springs FL
    Posts
    383
    +1
    33
    Just to clerify, is this a stock gpr1200 or a 65-u 1200 conversion?

  3. #3
    Quote Originally Posted by Echo View Post
    Just to clerify, is this a stock gpr1200 or a 65-u 1200 conversion?
    Its a gp800 hull and inside is a 65u 1200cc engine set to premix.

  4. #4
    Echo's Avatar
    Join Date
    Aug 2013
    Location
    Tarpon Springs FL
    Posts
    383
    +1
    33
    Ok that was the impression I got. Being clear on this fact can expidite sound advise. Idle speed is best set in the water. Just backing the ski down into ithe water and leaving on trailer is fine. Motor needs to warm to opersting temp, as idle speed will change a little when warm. Basically you just want to achieve a the lowest smooth idle possible. Mine are set at 1100ish. And i could go a little lower, but they vibrate a tad less here. The rpm on the display is not necc accurate. My to skis are set very close to the same rpm with a tiny tach, however the suv reads 300rpm lower on dash, and the gp1200 is a couple hundred higher on dash.

    That being said you have issues. Have carbs been rebuilt? You should be able to hit the limiter (or very close) with the idle screw without a load on tne motor. Are all 3 in sync? (Throttle plates moving as 1) are all 3 throttle plates completely closed with idle adjuster backed all the way out? If you achieve full closed before haveing adjuster backed all or nearly all the way out, or have to turn the screw alot to start getting plate movment, they out of adjustment. I am passing out atm. What kinda "restoration" did the ski receive.

    I wouldn't ride it till this issue is resolved. Properly functioning carbs is a must.
    Last edited by Echo; 10-16-2014 at 08:29 AM.

  5. #5
    Quote Originally Posted by Echo View Post
    Ok that was the impression I got. Being clear on this fact can expidite sound advise. Idle speed is best set in the water. Just backing the ski down into ithe water and leaving on trailer is fine. Motor needs to warm to opersting temp, as idle speed will change a little when warm. Basically you just want to achieve a the lowest smooth idle possible. Mine are set at 1100ish. And i could go a little lower, but they vibrate a tad less here. The rpm on the display is not necc accurate. My to skis are set very close to the same rpm with a tiny tach, however the suv reads 300rpm lower on dash, and the gp1200 is a couple hundred higher on dash.

    That being said you have issues. Have carbs been rebuilt? You should be able to hit the limiter (or very close) with the idle screw without a load on tne motor. Are all 3 in sync? (Throttle plates moving as 1) are all 3 throttle plates completely closed with idle adjuster backed all the way out? If you achieve full closed before haveing adjuster backed all or nearly all the way out, or have to turn the screw alot to start getting plate movment, they out of adjustment. I am passing out atm. What kinda "restoration" did the ski receive.

    I wouldn't ride it till this issue is resolved. Properly functioning carbs is a must.
    I rebuilt all 3 carbs and all three of the are good. And a also rebuilt the engine. So what you are basically saying is back the idle screw all the way out and start it and adjust it as it out? And also make sure it closed?

  6. #6
    Echo's Avatar
    Join Date
    Aug 2013
    Location
    Tarpon Springs FL
    Posts
    383
    +1
    33
    Back the idle screw out, but watch the throttle plates while you do it. If they fully close stopping movment before you have screw all the out, then you are losing adjustment. Also, they should fully close in sync at the same time. Either your linkage is outa wack, or low setting is way off, or something is wrong with the rebuild. Another thing you can do is back the idle screw all the way out, pop one end of the linkage off each carb and make sure all three plates are closed (they should be at this point) then make sure each linkage is properly adjusted to be real snug but not opening the plate on either carb when it is poped on. Also when linkage is disconnected verify that the tab on #1 is in contact(or really really close anyway) with the idle screw that is backed all the way out. Assuming everything looked good and you now have it all reconnected, all plates closed and idle screw will make contact with the ear in short order, either pull the the throttle on handle bars, or just use your finger where the cable connects to the carb and verify all three carbs are working as one.
    Last edited by Echo; 10-16-2014 at 10:42 PM.

  7. #7
    Quote Originally Posted by Echo View Post
    Back the idle screw out, but watch the throttle plates while you do it. If they fully close stopping movment before you have screw all the out, then you are losing adjustment. Also, they should fully close in sync at the same time. Either your linkage is outa wack, or low setting is way off, or something is wrong with the rebuild. Another thing you can do is back the idle screw all the way out, pop one end of the linkage off each carb and make sure all three plates are closed (they should be at this point) then make sure each linkage is properly adjusted to be real snug but not opening the plate on either carb when it is poped on. Also when linkage is disconnected verify that the tab on #1 is in contact(or really really close anyway) with the idle screw that is backed all the way out. Assuming everything looked good and you now have it all reconnected, all plates closed and idle screw will make contact with the ear in short order, either pull the the throttle on handle bars, or just use your finger where the cable connects to the carb and verify all three carbs are working as one.

    Well i am happy to say the non was required and i did test the ski out today after the rebuild and she ran like a dream. Before entering water she was at 2800-3000 on the gauge after i was able to screw that idle screw in a little, as soon as she hit the water and got to operating temperature she was then at 300-400 rpm and cruising about 5mph on the gauge and running good and solid. SO i am pretty happy with that . She did end up having a little bit of water inside after about 30min of riding but im sure that normal. Anyway thanks for all the help!

  8. #8
    Echo's Avatar
    Join Date
    Aug 2013
    Location
    Tarpon Springs FL
    Posts
    383
    +1
    33
    So, your problem was/is your tach. This moter will not hold an idle below 600ish rpms, and even then it will not take long to stall. I will check with gps tomarrow when we are out, however I am prtty sure neither of my skis are over 3mph idleing at 1kish

  9. #9
    Quote Originally Posted by Echo View Post
    So, your problem was/is your tach. This moter will not hold an idle below 600ish rpms, and even then it will not take long to stall. I will check with gps tomarrow when we are out, however I am prtty sure neither of my skis are over 3mph idleing at 1kish
    Well if its the gauge then im not worried about it. I think i might leave it be. Also quick question, if my engine is a premix then why do i also end up having black oil in the bottom after every ride?

  10. #10
    Echo's Avatar
    Join Date
    Aug 2013
    Location
    Tarpon Springs FL
    Posts
    383
    +1
    33
    Is the oil tank drained or removed? How much water was in the hull. Unless you were if very ruff waters, jumping, or something i call submaring you should of had next to no water in the hull. Could be an exhaust leak. That could leave black oilish water in hull.

Page 1 of 3 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. 2000 Yamaha gp1200 limited
    By Paultreisi in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 08-20-2015, 02:55 PM
  2. 2000 Yamaha GP1200 (Newbie Alert) Need all the help i can get!!!
    By Yamaden17 in forum Yamaha PWC Performance (2-stroke)
    Replies: 38
    Last Post: 09-01-2014, 09:47 PM
  3. SOLD 2000 Yamaha GP1200- Easy Project- $750- Near Austin TX
    By Marineking in forum Yamaha 2 Stroke Skis
    Replies: 4
    Last Post: 04-30-2014, 01:26 PM
  4. 2000 Yamaha SUV idle specs
    By mdavidthomas in forum Yamaha PWC Performance (2-stroke)
    Replies: 4
    Last Post: 05-08-2012, 12:32 AM
  5. 2000 virage tx idle set screw problem in carbs
    By twitty in forum Polaris PWC Performance
    Replies: 14
    Last Post: 07-01-2011, 10:03 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
  •