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Tuning Dual Carbs??

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  • Tuning Dual Carbs??

    So one carb is easy, especially on an old truck, but 2?! Yikes! Anyone have any special procedures that can help get these two carbs tuned together and synchronized? Any help would be great, thanks!

  • #2
    Re: Tuning Dual Carbs??

    Sorry, keep forgetting to put my boat motor... it's a Force 125, 1985 model. Thanks!


    • #3
      Re: Tuning Dual Carbs??

      Every model is different, different carbs, different specs, etc.You should try tuning 3 carbs feeding a 5 cylinder engine. !!If you rebuild them, do them separately.Do not swap parts between the 2 carbs.Sorry to mention it again, but "repair manual."Page after page of detailed instructions on link and sync, float levels, etc.


      • #4
        Re: Tuning Dual Carbs??

        Having read some of your other posts on this also, you had better get a Seloc manual PRONTO. I have a 88 125, wrenched all my life, and that is one complex SOB. If you don't know what you are doing, a very expensive mechanic is in your future. Sorry if I'm being blunt...just trying to help. Good luck!


        • #5
          Re: Tuning Dual Carbs??

          Not as blunt as Steelspike, Robby.His tag line used to be something close to, "He who works on an outboard without a manual has a fool for a mechanic."Kinda harsh, but oh, so true.


          • #6
            Re: Tuning Dual Carbs??

            Thanks guys! I totally understand, and I have a manual ordered and on the way. Should be here within a week or so. Maybe I should just stop posting until I have read the book and then don't understand. I'm just very ambitious about this boat because I love working with my hands, especially on motors. So thanks for all your help, and my apologies about the rediculous questions!


            • #7
              Re: Tuning Dual Carbs??

              Not rediculous questions, but the answers are just a bit too involved to be answered completely and accurately. We are better at answering specific questions about specific procedures.These motors are not high tech, but are still complex, in that most components work together to perform multiple functions.Powerhead supplies compression to fuelpump, which operates fuel recirculation system, and on and on.Remember, this is a 2 cycle engine, so messing around with the carbs not only effects the gas supply, it effects the oil supply as well. You want it running on the rich side rather than on the lean side, or you will starve your motor of lubrication and cause a major meltdown.There are plenty of things you can do until you get the manual and order some parts. You can clean the motor, scrub it down good. Remove the battery cables and clean them. CAUTION !!! Do not accidentally touch the cables to the wrong terminals on the battery - not even for a second - or you will do damage to the voltage rectifier.Clean and tighten all wiring connections. Check wires for damaged insulation. Look closely at the wires coming out from under the flywheel. They get brittle when the get old.Remove the prop so it is out of the way when you start working on the motor.Buy a couple quarts of lower unit lube, and a $5 hand pump makes the job alot easier, sold where they sell the lube.Get rid of all the old gas, clean out the gas tank.Use full synthetic TC-W3 oil in the fuel. Its only $20 a gallon at Walmart. The engine will run cleaner and smoke less. Also, use 87 or 89 octane gas with no alcohol if you can find it where you are.Replace old fuel lines and filters.Remove old unused wiring from the boat, if there is any. Its amazing how this stuff grows in older boats.Clean the boat.Use laundry detergent to clean the carpet, then rinse it very well.Check the wheel bearings.Rewire the trailer lights if need be.That should keep you busy for a while. Where are you in CO?I have relatives in Denver area, as well as Loveland.


              • #8
                Re: Tuning Dual Carbs??

                Thanks Roscoe and everyone else! I'm going to get started tomorrow! I've already began rewiring the trailer lights, but I believe that my truck has a faulty wire somewhere, I can't get the link from the truck to the trailer to function proporly. I live in Fort Collins. I'm sure if you know where Loveland is, you know where Fort Collins is. 10 mins away, at most. I goto Boyd Lake with my boat, it's a nice quiet lake in the middle of Loveland.


                • #9
                  Re: Tuning Dual Carbs??

                  I can feel your wanting to get out on the water as soon as possible, as I was the same way (still am!). But a cup of coffee and some time spent with the manual will save heartaches down the line. As Roscoe said, no high tech here, but the "ducks" really need to be in a row. Basically, turning screw "y" in without adjusting screw "X" will mess things up. The way the throttle shaft must be positioned is complex. Not sure on your motor, but on mine, just finding the right screw for the idle is hard..they all look good, but the wrong one will set the timing off instead. And one more VERY important thing...do NOT remove the screw going into the side of the gearcase to drain the oil. It will let the shift yoke fall down, and big bucks to dig everything out and replace it (its the little things in the manual that save you from some choice words). If your motors like mine (my manuals in the shop and I'm not), its WAY under the nose cone at the front, and just a small 1/8th Allen head screw. Thats the puppy to remove. Don't give up hope, you will be floating happy b4 ya know it...keep us updated.


                  • #10
                    Re: Tuning Dual Carbs??

                    My uncle worked in Ft Collins for many years. Retired now from Hewlitt Packard where he worked in the 70's 80's and early 90's,as a product developement guru.He lives on Lake Loveland (NE corner) about 2 miles west of Boyd Lake. The city did not want to maintain or repair the dam about 15 years ago, so they sold it to the homeowners. Then the homeowners owned the entire lake and shut out the public. The city had a fit. Don't know how they ever resolved that mess, but I think they started charging for access to the lake as a way to pay for the repairs and to restrict access.