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Excessive Smoke on Start Cured!

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  • Excessive Smoke on Start Cured!

    I'm posting this for my fellow Yammy owners that suffer the stares and coughs from innocent bystanders when you throw out a smoke screen every time you start your ride. I have suffered this humiliation for 2 years with the boat I bought used, and finally cured it with $7 of parts. Here's my tip: if your engine smokes alot on start (small cumulus cloud), maybe has a rough idle, but otherwise runs OK at speed, do the following FIRST before you try any of the 59 other smoke related fixes:

    1. REPLACE THE 2 OIL PUMP O-Rings. They are the O-rings shown behind the oil pump on the online Yamaha parts diagram. It takes all of 15 minutes. 2 bolts remove the pump. One O-ring is on the back of the pump; the other is on the circular spacer that fits around the pump drive shaft in the block. You'll have to gently coax the spacer out of the block with a screw driver to get to it.
    2. Then make sure the oil pump linkage is adjusted correctly. With motor off and throttle plates completely closed (which they should be since you're not stepping on the gas) shorten the linkage end so that the oil pump lever is just touching the stop-pin. Another 5 minutes work, maybe.

    My story: I have a 2001 VX225 VMax (otherwise known as the venerable OX66) on my Skeeter. I bought the boat 2 yrs ago and it has smoked like a brush fire every start, cold or warmed up. The idle has been rough, and it has recently started to die on starting unless I immediately punched it. Other than that, it runs good on plane and does 68 mph+. It does seem to use more oil than one would think normal, but I never really measured it.

    OK, I'm a tinkerer, and have spent alot of $$$ and laid awake in bed going thru possible causes for months. Here's what I've done thus far:
    -new O2 sensor $300
    -new LP fuel pump $60
    -new plugs,twice...$20 X 2
    -checked filter in VST (it was cleaner than a whistle) ...$28 gasket
    -removed injectors and had tested/cleaned - $108
    -checked fuel press regulator screen and diaphragm (was clean and OK)

    Then I finally read posts here by RODBOLT17 on similar issues. The man is a certifiable Yamaha genius. He apparently attended MIT and received his PhD in Yamaha-ology. His posts enlightened me to the sinister nature of those 2 little oil pump O-rings. Frankly, I thought my engine was doomed to smoke its way thru the remainder of its life, but $7 later, VOILA! Cured!

    A final note: some of thie stuff I did should be done periodically. I did have a bad LP fuel pump (slight leakage), but it was not causing the smoke. I did clean my O2 sensor before replacing, but went ahead and replaced it hoping that was the magic bullet. Nope. Didn't improve anything. I will say the injector cleaning made a noticeable difference in the performance and I'm glad I did that. Much more pep. I took them to InjectorRX in Houston (Chris did them in one day for $18/injector). He used ultrasonic bath to clean and replaced filters and o-rings on each. If your injectors are dirty, mail them to Chris. No amount of gas additive will remove the particulate crap that gets in them and plugs them up.

    So, if you have an older 2 cycle that smokes alot on start, but otherwise runs OK, try the 2 things I mentioned FIRST. If that doesnt help, you are only out $7 and a few minutes work.

  • #2
    everything is good EXCEPT your oil pump adjustment.
    at idle shutters are NOT fully closed.
    your link arm adjustment is still off.
    its not uncommon to have to cut off about 5 threads on a 3.1L engine to accomplish the .005-.020" stopper to arm clearence with the shutters FULLY CLOSED.
    means ether backing off the shutter stop screw OR unclipping the lower two shutters.
    but the OX66 is a good system if one takes the time to understand a basic closed loop speed density EFI system.


    • #3
      Hi, Nice work. I have a 1995 20 hp Precision Blend that i just bought and it smokes like cheech and chong on a cold start. Does any of this apply to my wee-board? Do I have the same system on mine?


      • #4
        RodBolt17, once again you are correct, sir. Before I adjusted the oil pump linkage, I actually backed the idle adj screw out to make sure the throttle plates were completely closed (assuming the plates are all aligned together, which they appear to be). And then, lo and behold, I found that I had to grind off some threads on the link rod to accommodate the amount of adjustment needed to get the oil pump lever to the stop pin.

        RodBolt, a question for you: what other engines would this o-ring fix apply to? practically any that have an oil pump, or just the OX66? e.g., Is Yammadabadoo's engine applicable?


        • #5
          Would this help a 1988 200 with the old style oil pump also?


          • #6
            on EFI engines we dont like to call it an idle screw.
            its a shutter stop screw.
            on the 20 HP, no its a different animal.
            you can check the pump orings and adjust ments per the proper service manual.
            on the 88 200, does it have the original kien pump or has it been replaced with a mikuni pump ?


            • #7
              One of my motors has the Kehin and the other the Mikuni pump. The one with the Mikuni smokes more on startup. I'm thinking that might be a good thing. The Kehin is known for draining oil out (not as good check valve setup)....right?


              • #8
                Would this apply to my 95 250 2 stroke as well? It is smoking a lot on start up and running rough till 1700 RPM.


                • #9
                  BTW -
                  If you're reading this and you have a 4-stroke that smokes just at start up, make sure you are storing the motor level.

                  My boat stays in a boat slip and if I store the motor trimmed down below "level" sometimes I get a bit of smoke right when I start her up. Motor is a 2004 F90 with about 400 hours. The smoke will last about 30 seconds and then goes away. I called Yamaha on this and they told me about storing it level......

                  It has NEVER smoked if I store the motor level or above.


                  • #10
                    to many folks asking questions on oil pumps that are different .


                    • #11

                      I'm working on my 95 250 2 stroke. How do you get that spacer out?? Does it butt up to the shaft with the washer separating them? Mine is in there pretty good and I can't get it out!
                      Last edited by Wellcraft238; 12-08-2012, 03:13 PM.


                      • #12
                        Great read! I feel that I may need these o'rings replaced on my Vmax. Large plum with every start and very rarely noticed any other time while running. Are there any photos or diagrams of this? It would be helpful for me having little experience with any outboards let alone this one? Thanks for any help and insight.


                        • #13
                          we may have to search and find you to apply thumb screws to keep you from bringing up old threads.

                          best to start a new thread of you own with all info needed


                          • #14
                            Originally posted by 99yam40 View Post
                            we may have to search and find you to apply thumb screws to keep you from bringing up old threads.

                            best to start a new thread of you own with all info needed
                            Might I suggest a Taser?

                            Thumb screws are so old school.


                            • #15
                              not sure what voltage they put out when bedded into you,'
                              but I have been curled up from about 2700 volts AC running hand to hand.
                              I am sure tasers are about the same
                              not much you can do about it at the time
                              carefuller posters we will find you