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30hp 3cyl, cyl 2 dead

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  • #16
    K, fresh plug grounded to block shows thick bluish white spark.
    Reexamine the bowl and it looks seated perfectly from just looking at it. Squeezing the bulb doesn't show a leak anywhere.
    To be honest I had the motor tilted up earlier so I don't know if maybe it came from the throat or the bowl.

    If there's anymore things I Caan check without taking off the carbs I'm all ears, otherwise we will have to wait till Friday to continue when I rerereexamine carb 2 =/

    Thanks for all the help and suggestions so far. Really is a great crew on here


    Btw before I put carb 2 back on I tested it upside down blowing into it and it didn't allow anything, but I didn't know about vaccuum testing. Is that done upside down to so the needle is seated?
    Last edited by walleyehunter13; 12-17-2016, 06:29 PM.

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    • #17
      Originally posted by walleyehunter13 View Post
      K, fresh plug grounded to block shows thick bluish white spark.
      Reexamine the bowl and it looks seated perfectly from just looking at it. Squeezing the bulb doesn't show a leak anywhere.
      To be honest I had the motor tilted up earlier so I don't know if maybe it came from the throat or the bowl.

      If there's anymore things I Caan check without taking off the carbs I'm all ears, otherwise we will have to wait till Friday to continue when I rerereexamine carb 2 =/

      Thanks for all the help and suggestions so far. Really is a great crew on here
      Tilting the engine shouldn't have fuel leak normally (unless theirs an issue).

      You'll find it!
      Scott
      1997 Angler 204, Center Console powered by a 2006 Yamaha F150TXR

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      • #18
        Originally posted by TownsendsFJR1300 View Post
        Tilting the engine shouldn't have fuel leak normally (unless theirs an issue).

        You'll find it!
        Just edited my other post while you made this one, but when vacuum testing the carb it should be upside down seating the needle right?

        Everytime I tilt the motor I get a leak also
        Last edited by walleyehunter13; 12-17-2016, 06:32 PM.

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        • #19
          not sure where the gas is when you say on the bottom of carb#2, but if it is dumping in the carb throat, then yes you have trash, float, or something not letting the needle seat properly.

          also I would think that the fuel level should be below the bowl gasket, so not sealed properly still should not allow fuel to leak out the top of bowl.
          I could be wrong because I do not know exactly what your carbs is set up like, but most should not have a level that high.

          edit
          Sorry I had to go next door to help a neighbor with some lighting problems so i did not see these other posts that came across
          Last edited by 99yam40; 12-17-2016, 06:48 PM.

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          • #20
            Originally posted by walleyehunter13 View Post
            Just edited my other post while you made this one, but when vacuum testing the carb it should be upside down seating the needle right?

            Everytime I tilt the motor I get a leak also

            That's helpful!..

            Obviously the carb isn't designed to operate upside down. (Prior post from you)- Blowing into it while upside down, your pressure is working AGAINST THE WEIGHT OF THE FLOAT(which is now closed). If you blew hard enough, you'd get air thru...

            But if using a vacuum gauge on the inlet fuel nipple, yes, you want the float closed. You shouldn't get any air past there...

            You can also (with the carb upside down), hook up a fuel/liquid source to the inlet. With the float bowl off, lifting the float (opening the valve) fuel will flow (we KNOW that's happening).

            When the float is closed (simply with gravity), no fuel should be coming out of the valve. You can also put the carb in the correct orientation. Lift the float(closed)-NO fuel should flow. *I suspect you'll see fuel flowing when it shouldn't (flooding the cylinder).

            When you tilt the engine now, can you pin point where the leak (probably have to dry it well) is coming from specifically??

            Most carbs have an over flow that'll dump fuel outside the carb vs pouring it down the cylinder and possibly having an hydraulic lock.. Excess fuel could also be coming out wherever the float bowl vents...
            Last edited by TownsendsFJR1300; 12-17-2016, 07:01 PM.
            Scott
            1997 Angler 204, Center Console powered by a 2006 Yamaha F150TXR

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            • #21
              Originally posted by TownsendsFJR1300 View Post

              Most carbs have an over flow that'll dump fuel outside the carb vs pouring it down the cylinder and possibly having an hydraulic lock.. Excess fuel could also be coming out wherever the float bowl vents...
              Only place I have seen for fuel to overflow out of carbs was the vent on top of carb and it is above the passages that dump into the throat of carb so it would come out in the throat before the vent

              where is this overflow you speak of?
              Last edited by 99yam40; 12-18-2016, 03:15 PM.

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              • #22
                Originally posted by TownsendsFJR1300 View Post
                That's helpful!..

                Obviously the carb isn't designed to operate upside down. (Prior post from you)- Blowing into it while upside down, your pressure is working AGAINST THE WEIGHT OF THE FLOAT(which is now closed). If you blew hard enough, you'd get air thru...

                But if using a vacuum gauge on the inlet fuel nipple, yes, you want the float closed. You shouldn't get any air past there...

                You can also (with the carb upside down), hook up a fuel/liquid source to the inlet. With the float bowl off, lifting the float (opening the valve) fuel will flow (we KNOW that's happening).

                When the float is closed (simply with gravity), no fuel should be coming out of the valve. You can also put the carb in the correct orientation. Lift the float(closed)-NO fuel should flow. *I suspect you'll see fuel flowing when it shouldn't (flooding the cylinder).

                When you tilt the engine now, can you pin point where the leak (probably have to dry it well) is coming from specifically??

                Most carbs have an over flow that'll dump fuel outside the carb vs pouring it down the cylinder and possibly having an hydraulic lock.. Excess fuel could also be coming out wherever the float bowl vents...
                Forgive me if this question does not make sense. Just a little confused...

                How are you going to\where have you blown through the carb 2 fuel inlet passage? I ask this because it looks to me that there is no hose that feeds the carb. It looks like it's fed directly from the fuel pump through a passage cast in the carb. It seems to me you'd have to remove the pump, use a rubber conical shaped tip pressed against the orifice passage on that carb on a regulated air supply hose. I guess you could remove and plug one of the feeds , and apply air pressure to the second also blocking the fuel pump inlet from the filter?

                Is this your set up in the image below?

                [IMG]Carb.1 by Charles Postis, on Flickr[/IMG]
                Last edited by cpostis; 12-17-2016, 08:54 PM. Reason: ./?
                Chuck,
                1997 Mako 191 w/2001 Yamaha SX150 TXRZ Pushing Her

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                • #23
                  Originally posted by cpostis View Post
                  Forgive me if this question does not make sense. Just a little confused...

                  How are you going to\where have you blown through the carb 2 fuel inlet passage? I ask this because it looks to me that there is no hose that feeds the carb. It looks like it's fed directly from the fuel pump through a passage cast in the carb. It seems to me you'd have to remove the pump, use a rubber conical shaped tip pressed against the orifice passage on that carb on a regulated air supply hose. I guess you could remove and plug one of the feeds , and apply air pressure to the second also blocking the fuel pump inlet from the filter?
                  From post #16:

                  "Btw before I put carb 2 back on I tested it upside down blowing into it and it didn't allow anything, but I didn't know about vaccuum testing. Is that done upside down to so the needle is seated?"



                  Obviously, it needs to come apart because of the fuel pump but there isONLY ONE ONE NEEDLE / SEAT /
                  FUEL INLET
                  for that carb.

                  If there is something different to allow fuel to #2 needle and seat, removing the float bowl, (leave everything else assembled) and then get fuel to the carb. Closing / rasing the float should stop the fuel flow. If it doesn't / leaks, its going to flood..

                  Think outside the "box" to check / test what you need to... We need to confirm the needle and seat are sealing and the float is intact..



                  .
                  Last edited by TownsendsFJR1300; 12-18-2016, 07:31 AM.
                  Scott
                  1997 Angler 204, Center Console powered by a 2006 Yamaha F150TXR

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                  • #24
                    man yall like to make stuff complex.
                    the easiest way is to remove the air box.
                    idle the engine.
                    if the needle is leaking it will either run out of the carb air vent or bubble out of the emulsion tube.
                    a leaking fuel pump will create issues as well.

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                    • #25
                      Would the air vent be the opening that seems to passage to the a/f pilot screw?

                      Also, I replaced the fuel pump diaphragms recently, it was doing this before the replacement also. Would it be the part between the diaphragms with the metal flaps that would cause leaking? Or did you mean not properly sealed gaskets around the pump causing the leaking.

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                      • #26
                        Originally posted by walleyehunter13 View Post
                        Would the air vent be the opening that seems to passage to the a/f pilot screw?

                        Also, I replaced the fuel pump diaphragms recently, it was doing this before the replacement also. Would it be the part between the diaphragms with the metal flaps that would cause leaking? Or did you mean not properly sealed gaskets around the pump causing the leaking.
                        Not sure what you are referring to on the bolded part about passage.

                        I am sure the fuel pump diaphragm is what Rod was referring to as far as leaking into the motors crankcase causing over rich condition

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                        • #27
                          pulled the carbs, took off the bowl and put a little rubber nozzle that fit on the inlet passage and hooked up a vaccuum pump and it holds vaccuum.
                          Still same problem when running though.
                          Float is intact, not filling with fuel, and set at manual specs of 15mm (all mine are at 15.2 actually but manual says 15mm +- 0.5mm)
                          Very stumped on this.

                          So now the likely culprit is the fuel pump right? Any way I can test or check if it's leaking into the vaccuum port that runs the pump?
                          I replaced both diaphragms a few weeks ago on advice from a friend with a similar problem and it changed nothing.

                          Is there a possibility there is something wrong with the pump body.
                          This part

                          http://www.boats.net/parts/detail/ya...415-00-00.html
                          Last edited by walleyehunter13; 12-23-2016, 06:00 PM.

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                          • #28
                            I don't think you ever answered where the fuel was coming from EXACTLY when tilted. Maybe some brake cleaner, let it dry and some baby powder in the area. then fill and tilt...

                            Re the fuel pump, it certainly can't hurt to very closely inspect yours for any hairline cracks. Perhaps a little pressure on the nipple to check for cracking at the base of the nipple(s), etc...

                            Again, maybe with the housing, plug (best you can and try to pull a vacuum at the different ports).

                            I'm out of idea's (as long as you do have spark at the tip of the spark plug hooked to the lead, grounded to the block-not fouled)

                            Good luck...


                            Rodbolt???

                            .
                            Last edited by TownsendsFJR1300; 12-24-2016, 08:06 AM.
                            Scott
                            1997 Angler 204, Center Console powered by a 2006 Yamaha F150TXR

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                            • #29
                              I'll try some talcum powder I got laying around. Thanks for the idea.

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                              • #30


                                I see some leakage around the intake gasket where cyl 2 and 3 are around the carb bolts into the intake. Nothing from the carbs though. Also noticed some arcing between the intake and crankcase but I don't think that has anything to do with my problem since I'm seeing good spark.
                                No gas everywhere like before, I did polish the float seat when I cleaned it out yesterday so maybe that was part of the problem, but not the whole problem.

                                So time to replace an intake gasket? Or is that acceptable(doubt it)? It's not leaking visible fluid but the powder is getting wet. I'll coat it, let it sit 10 mins and the power in that area is all wet again.


                                Here's the same pic but I circled where I'm getting some leak

                                Last edited by walleyehunter13; 12-24-2016, 01:33 PM.

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