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98 yamaha 115 hp - won't start when cold

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  • 98 yamaha 115 hp - won't start when cold

    This is an updated post from previous post - starting a new one so that people don't have to wade through my learning curve. Problem has been ongoing difficulties with cold start that has progressed to no start when cold. Several issues have been fixed that were probably contributing issues - bad cables and corroded connections.

    CURRENT problem: motor won't start when cold, if it is warm it starts up perfectly and runs great - if it sits after you try, unsuccessfully, to start it, the plugs are wet - it will start if you spray carb cleaner into the carbs

    Boat has been at mechanic for 2 weeks - we initially took it to him to just help us diagnose the problem - he was pretty confident that he'd know what it was in an hour. I picked up the boat yesterday - not because it is fixed but because the mechanic says he has exhausted all he knows to do - he's been in contact with yamaha several times who says there is no reason boat isn't starting when cold.

    So....I am determined to find the answer - have a bet going with the husband - I know there are those of you out there who are saying "she's a girl...she is wasting my time'....But, I am my father's daughter.....he could fix anything by reading a book, I might not have the up front knowledge, but I am putting in the time to understand this stuff. I rebuilt the carbs on MY 99 XLT 1200ltd - me, with the greenhulk forum knowledge - my husband did his own - I even painted and posted pics So, to provide some extra incentive for help - I will send a batch of fresh homemade pear pie cookies made from pears picked from my yard to whoever helps me win the bet and find the daggum answer to this motor's problem. I hear the scallops are plentiful and they are calling my name every time I close my eyes.

    here's what I know:
    1. model is C115TXRW
    2. battery cables replaced, voltage checked and seems to be good
    3. new ignition switch
    4. batteries are new this season and check out good
    5. starter checked out and good
    6. linkage has been checked and solenoid is good
    7. connections and cables have been checked
    8. butterflies are closing
    9. carbs have been checked and clean
    10. bulb was tested and is not backleaking
    11. correct procedures are being used for starting motor

    - all of this was done by local mechanic - husband is an electrician and rebuilds cars as hobby - mechanic is very reliable with great reputation - he does not just start replacing things (ex: first thing yamaha said was "rebuild carbs", which he didn't 'cause he knew that wasn't the first place to start). He was willing to find the problem and then let my husband fix it - but, he finally had to give up b/c he needed to get back to making money, which I so understand.

    My thoughts....he must have missed something. He has done everything that I have read listed in the 100's of posts I have read related to this issue. This seems to be a common problem - mechanic really thought he'd have it diagnosed and fixed in one hour - for his sake I'd hate to know how much time he actually has in thinking, looking, talking and working on it - I baked him a pear pie - probably need to send him one a week.

    My question.....with what is currently occurring, any ideas as where to start? What would be the most likely cause of no cold start and wet plugs?

    We really need to get this fixed - we have 3 adopted young girls with special needs - it would not be good to go out on boat with them a rely on the "spray the carbs" method.

    I am determined that this is not gonna beat me - help!!!

  • #2
    Re: 98 yamaha 115 hp - won't start when cold

    update - from reading other threads with similiar issue, I taped up the air intake openings to carb on both sides of motor - lo and behold the boat cranked. Husband heard it and came out - said it was "blind luck" - hmmmm.

    He took off back of motor to expose the butterfly plates - as he was loosening the bolts, gas began leaking out. He adjusted the solenoid and linkage - at first it wasn't closing consistently and he had to lower it slightly. But, I had raised it today, so he thinks I had it too high. He had watched mechanic last week when he checked the solenoid and it was closing butterflies consistently. But, it did crank with the air intakes blocked - doesn't that indicate the choke system? We're gonna let it cool off and try again.

    Husband is concerned about the excessive gas - while motor was running, he closed the choke plates several times - it did bog the motor down as expected, but there was a lot of extra gas, the gas ran down the outside of the carbs where the butterfly plates are. Is this normal? Should there be that much extra gas being pulled that it will leak out?


    • #3
      Re: 98 yamaha 115 hp - won't start when cold

      Has the compression been checked? How many hours? I assume its cranking just not starting.


      • #4
        Re: 98 yamaha 115 hp - won't start when cold

        i have just one word to say ........BATTERY

        i'm so glad the boat is running but i am so aggravated that it cost us what it did.....these forums were invaluable - i read and read and read and read.....husband had battery tested, boat was at shop for 2 weeks - he tested, replaced battery cables, ignition - no one could find the answer - when we got the boat back, i talked my husband into replacing fuel pump because i read it was a good preventative measure, so even if that didn't fix the problem at least it wasn't money wasted - that didn't fix the problem - i then talked him into replacing the battery as ours was on the very low end of minimum requirements and it just seemed sluggish, but has always seemed that way - got a bigger battery and that sucker fired right up -

        could have also been a fuel issue - prior to changing fuel pump the hose right after fuel pump would swell and leak when bulb was squeezed - it didn't occur after pump was changed

        suggestion for the powers that be - there is so much wonderful information on these boards but it is difficult to access - i searched and searched to run down the info i needed - so many people are having the same problem year after year - it seems that often people are getting tired of answering the same questions - posts 5 years ago have a lot of responses whereas those general common problem posts now often don't even get a response - it would be so helpful to people if this forum could find a way to make it easier to access the information maybe by consolidating basic information into sticky's - i have a master's degree in education and i struggled with searching for the info i needed - i spent hours and hours reading and searching probably close to 50-60 hours

        but, glad i won the bet and glad the boat is running - can't wait to go scalloping aka my underwater easter egg hunt -


        • #5
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          Re: 98 yamaha 115 hp - won't start when cold

          Did you ever look at the frequently asked question section of the forums? That is always a good place to look to start out with.

          # 3 would have solved your problem as long as you tested properly

          Also communication is a problem a lot of times as all do not say or mean the same thing when saying something.
          For instance, you wording" took off back of motor to expose the butterfly plates" does not make a lot of sense as the carbs and butterfly plates are on the front of the motor not the back. You also said the battery had been tested so people will not tell you to test it if you have already done so and said it was good.

          But glad you got it fixed and are able to use it again, have fun.