HaHa HaHa:  0
Page 4 of 5 FirstFirst 12345 LastLast
Results 31 to 40 of 47

Thread: Yamaha 115 2 stroke fouling plugs at idle

  1. #31
    Join Date
    Aug 2017
    Location
    NE AL
    Posts
    4,019
    Post Thanks / Like

    Default


    Quote Originally Posted by striperking View Post
    When you take them off and take them apart do you have a ultrasonic cleaner to clean them in before you put the rebuild kit in them?
    No I don't.

  2. #32
    tlefire's Avatar
    tlefire is offline Crappie.com Legend * Crappie.com Supporter
    Join Date
    Mar 2016
    Location
    Alabama
    Posts
    7,188
    Post Thanks / Like

    Default

    Hey Brad.....Bucks Boats had some go deals going on some leftover 16 and 17 models still in the crate last time I was there.
    2018 G3 Sportsman 17
    2018 Yamaha F90 four stroke
    Ultra 106sv bow/console
    Livescope Terrova 24v Ionic lithium batteries
    Likes Slabprowler LIKED above post

  3. #33
    Join Date
    Aug 2017
    Location
    NE AL
    Posts
    4,019
    Post Thanks / Like

    Default

    Hush. LOL

    Gotta get the kiddos out of school first....

  4. #34
    Join Date
    Jan 2019
    Location
    Benton, KY
    Posts
    660
    Post Thanks / Like

    Default

    Sure sounds like the jets might be the wrong size/too big. When you get your rebuilt kit, I would look closely at the jets they provided versus what you are currently running, and then do some research to find what exact size you should be running.

    I rebuilt the carb on a 4-wheeler recently, the kit manufacturer had stuck the wrong jet size in the kit (too small) and I didn't notice it. I couldn't figure out why in the world it was running so lean until I finally started researching the jet sizes and discovered the wrong size in the kit.

    Just thinking out loud here, I also know on the 90s model Yamaha jetskis that I had, the oil pump sent a constant pressure of oil into the carb, which made it smoke like crazy at idle and shortened plug life. A 115 hp Suzuki outboard I also had was the same way with the smoke and oil pressure. Does yours smoke an awful lot at idle?

  5. #35
    Join Date
    Aug 2011
    Location
    Jonesboro, AR
    Posts
    532
    Post Thanks / Like

    Default

    Outboard carb kits are nothing like atv kits. You either get a gasket kit or gaskets plus float, needle and seat. (Never a jet) It's always possible that jets have been swapped out (or drilled out) by someone that didn't understand carbs but I suspect the carbs need to be fine tuned. The symptoms are changing from one end to the other as different settings are being tried. Also, if it get's to that point, he will need to measure the jets with numbered bits and not rely on the engraving on the jet. I've been down that road too many times with motors that someone thought that more fuel simply meant more Hp.
    I'd rather be fishing.

  6. #36
    Join Date
    Aug 2017
    Location
    NE AL
    Posts
    4,019
    Post Thanks / Like

    Default

    sliderman, one thing that I don't think I've mentioned is that the motor always runs great when using the warm up lever. It doesn't act up unless it's in gear. Does that give any more indication what the problem might be?

    I'll check the jets when I tear it down again.

  7. #37
    Join Date
    Aug 2011
    Location
    Jonesboro, AR
    Posts
    532
    Post Thanks / Like

    Default

    Yes. The range between too much and not enough idle mix for what you need is very narrow. Idle in neutral puts very little 'load' on the engine. Especially on a water hose. On the lake, a little more load is placed on the engine as it has to force the exhaust down below water lever. In gear and on the water is way more. And.... If you leave the boat on the trailer, it adds even more load because the boat is not moving forward. The more load the motor has, the richer the mix needs to be. The only way to really tune the idle is by backing down the ramp and making adjustments with it on the trailer. If it will idle for 5 minutes in gear without stalling and be responsive to throttle, you're where you need to be. If you goose it and it stalls, your too lean and if it stumbles and smokes before catching it's breath, you're too rich.
    I'd rather be fishing.
    Likes Redge LIKED above post

  8. #38
    Join Date
    Aug 2017
    Location
    NE AL
    Posts
    4,019
    Post Thanks / Like

    Default

    Ok, thanks. I never run it on muffs. I have a 55 gallon barrel cut out to fit that I put the motor in to run it. I can run it in gear in the barrel.

  9. #39
    Join Date
    Aug 2017
    Location
    NE AL
    Posts
    4,019
    Post Thanks / Like

    Default

    So.....

    I don't know how the boat was running as good as it was.

    I figured out why she's starving for fuel above 4000 rpms. The main diaphragm in the fuel pump has a tear in it. A ONE YEAR OLD, OEM Yamaha fuel pump.

    I think I figured out why it's fouling plugs. I put 5 psi of air pressure on the bowls and all 4 needles leak. Two seep and two are really bad. I sprayed soapy water on them and the 2 best ones suds around the needle. The two worst ones blew bubbles.

    Two carb kits ordered and new diaphragms for the fuel pump. Maybe I'll be up and going by mid week next week.
    Likes "G", crappiemax, Slabprowler LIKED above post

  10. #40
    Join Date
    Aug 2011
    Location
    Jonesboro, AR
    Posts
    532
    Post Thanks / Like

    Default

    Multiple issues like that can make you pull your hair out.
    I'd rather be fishing.
    Thanks strmwalker thanked you for this post

Page 4 of 5 FirstFirst 12345 LastLast

Tags for this Thread

Posting Permissions

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

BACK TO TOP