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    Trolling valves

    my 5788 has trolling valves. I have never used them. At one point in the past the boat was a charter and has a label saying never use over them which I presume was just to protect against inexperienced use or misuse.
    Pic of the controls attached.
    Couple of questions.

    1. Are they bad for the transmissions and should be avoided?
    2. How do they work. Can I just pull up the two controls while I’m neutral?
    3. I think they retard the transmissions through a special clutch. Any idea how slow I will go when engaged. Right now my idle speed is between 6 and 7 knots.
    4. Anything else I need to consider
    5. How do I know if something is not right with them if I try them.

    Thanks In advance.
    BLOG ABOUT MY BOAT... www.seattleboater.com
    5788 Man 610's- Love Her !
    Sold:Bayliner 3587 | Extended Hull

    #2
    I don't know for all transmission types but on Hurth/ZF transmissions, the trolling valve allows you to bypass some of the oil supplying pressure to the clutch packs thereby "slipping the clutch" to get your desired shaft rotation speed. This creates heat which is not a problem at LOW rpms only. If you have the trolling valves engaged and hit the throttle you will likely be buying/repairing your transmission! So as long as you use them correctly, there is no danger. I am no expert in this area but did want trolling valves because my boat even on one engine goes to fast to troll. Harbor Marine in Everett are the go to transmission people. I about fell over when he gave me the price, $1800 each but ironically the same part if ordered with a transmission was only $495 so I declined and solved my problem with a trolling bag for $125 Hope this helps! Brad
    Brad & Michelle
    Bo (Yellow Lab)
    1993 3688 "the Kraken"
    Hino W06 250HP
    14' Avon RIB, 50hp Tohatsu
    Moored at Shelter Bay
    LaConner, WA

    Comment


      #3
      Thanks brad.
      I guess I have been nervous to engage them in case anything is up with them. Anyone know if there is anything to look for when engaging them. I have been a little afraid to use them
      mynplan would be.
      Neutral.
      Pull both the switches all the way out.
      Me gage fwd gear
      check speed.
      Do not engage any throttle while using.

      Will try this weekend.
      BLOG ABOUT MY BOAT... www.seattleboater.com
      5788 Man 610's- Love Her !
      Sold:Bayliner 3587 | Extended Hull

      Comment


        #4
        Are they quoting installation and the other parts to make it work such as control cables and levers and labor to install?
        Pat says: DO-IT-RIGHT THE FIRST TIME!

        Bayliner 3870 "ALASKA33)
        Twin 350 GM power
        Located in Seward, AK
        Retired marine surveyor

        Comment


          #5
          So they don’t seem to work. I’m pulled the two switches out all the way. They extend about 4 inches. Then put her in gear and nothing. Gears don’t engage and of course didn’t move.
          Pushed them all the way back in and back to normal. Gears engage as normal. Tried twice, nothing.
          Any tips/ thoughts?
          BLOG ABOUT MY BOAT... www.seattleboater.com
          5788 Man 610's- Love Her !
          Sold:Bayliner 3587 | Extended Hull

          Comment


            #6
            Did you throttle up some, a troll valve lets the clutches slip.
            Pat says: DO-IT-RIGHT THE FIRST TIME!

            Bayliner 3870 "ALASKA33)
            Twin 350 GM power
            Located in Seward, AK
            Retired marine surveyor

            Comment


              #7
              No I thought the whole point was they were only to be used at low revs.
              BLOG ABOUT MY BOAT... www.seattleboater.com
              5788 Man 610's- Love Her !
              Sold:Bayliner 3587 | Extended Hull

              Comment


                #8
                Instead of acting like an on / off switch, yours could be a variable trolling valve and moving it out a little bit lets a small amount of oil bypass the clutches which results in a bit of clutch slippage and slightly reduced speed. As you move it further out, more clutch pressure is lost untill it finally doesnt result in any forward motion.
                Stan
                2001 Bayliner 4788
                Underhulls
                Bow & Stern Thrusters
                Hydronic heater
                330 Cummins

                Comment


                  #9
                  What Stan said...you must ensure that the control lever can be moved in small increments.

                  it is not recommended to use trolling valves for docking purposes.
                  Do I need a trolling valve?

                  Trolling valves are used to reduce the minimum speed of a vessel. To accomplish this the shaft speed of the vessel must be reduced. This may be required for fishing purposes or while the vessel is operating in confined spaces, and minimum wake is required.
                  What is a trolling valve?

                  A trolling valve is merely a variable pressure regulator, which works with the existing pressure regulator to provide for a low range of pressure control. This pressure range of operation is between 7 PSI (.5 bar) and 95 PSI (6.5 bar). This lower pressure will cause the clutch pack to slip allowing the propeller shaft to operate slower than the normal "in gear" speed.

                  What's the valve's range of operation?

                  For practical purposes there is no minimum shaft speed that can be obtained. Under certain circumstances the shaft may stop turning. The maximum shaft speed is expressed as 70% of the normal "in gear" shaft speed. Operation of the trolling valve to obtain greater than 70% of the normal shaft speed will lead to clutch "chatter" and will damage the gear box. The engine speed may be increased if a greater shaft speed is desired. Engine speeds must be at or near idle during trolling operation.

                  For example: If the normal engine idle speed is 600 RPM and the gear ratio is 2:1, then the maximum shaft speed during trolling should be limited to (70% of 300 SRPM) 210 SRPM. If a greater shaft speed is required, the engine idle could be increased. In this case the engine RPM should not be raised above 857 RPM since this RPM is equivalent to 600 RPM in gear (no trolling) normally.

                  The engine speed should never exceed 1000 RPM during trolling. Some applications have a lower limit.

                  Can I use my trolling valve to dock my boat?

                  The clutch pressure is reduced during trolling. This means the response from ahead to astern or vice versa is very slow. This reduced or lack of control could lead to damage or injury should the vessel contact fixed objects. For this reason, it is not recommended to use trolling valves for docking purposes.

                  How do I control my trolling valve?

                  ZF offers both electrical and mechanical trolling valves. For mechanical valves, any means of moving the control lever can be used to operate the valve. If mechanical systems are used, you must ensure that the control lever can be moved in small increments to ensure repeatability of operation. Electric valves have proved to be the more easily controlled type. Many marine control systems are available to properly control the valve. Electronic control systems allow for easy adjustments of the valves' range of operation to suit different applications.

                  Regardless of the type of valve or control system, there must be provisions made to prevent the operation of the vessel in a situation so as to damage the clutch plates in the gearbox.
                  Joon, Kathy, Jaden & Tristan
                  Uniflite 42 AC, DD 671N
                  93 3058 sold
                  92 2855 (day boat)
                  91 Fourwinns 205 (lake boat)
                  Longbranch WA
                  Life is Good

                  Comment


                    #10
                    Thanks for the input. So here is what I think I am hearing.
                    My set up is what seems to be a cable running down to the engine which clearly operated the valve.
                    There are no increments but you can pull it out to about 4 inches at full extension.
                    When I tried yesterday I went to neutral engaged all the way out. Got nothing.
                    Sounds like what I should do is...

                    -Put in gear at idle.
                    -while moving slowly pull out the lever trying to keep each valve equal (remember no increments)
                    - observe if just partially out my speed drops at all.

                    I guess i had concerns about engaging while underway. And thought I had to be in neutral.

                    BTW no desire to dock with these. My use would only be fishing and maybe some no wake areas with slow speeds. As at idle I make 6-7 knots which can be a challenge
                    BLOG ABOUT MY BOAT... www.seattleboater.com
                    5788 Man 610's- Love Her !
                    Sold:Bayliner 3587 | Extended Hull

                    Comment


                      #11
                      I have trolling valves on my 5788 and haven't found a use for them. I don't fish so that might be the reason. I've tried them a few times to keep the boat under six knots when going through a no wake area but in all cases I find that prefer to just put one engine in forward and the other in neutral and put some rudder in. I'll try them again if I ever buy a fishing pole.

                      Cheers,
                      Jim V.
                      5788 in the Everett Marina

                      Comment


                        #12
                        is 6-7 knots at idle normal for your boat? I'm new to this with a 3870 but mine just barely creeps along at dead idle. I haven't tried trolling yet but I don't think I'll have any problem on one engine.

                        Comment


                          #13
                          Jim. Are yours the same set up as mine and if so any guidance on how you used them?

                          bryguy- yup huge props fairly normal to be 6 knots plus at idle
                          BLOG ABOUT MY BOAT... www.seattleboater.com
                          5788 Man 610's- Love Her !
                          Sold:Bayliner 3587 | Extended Hull

                          Comment


                            #14
                            Hi Simeon, My guess is that we have the same trolling valves on the same transmissions (ZF311) but it sounds like our controls are different. I have the ZF Mathers Microcommander electronic engine controls. They have one lever for each engine and one button on top of the housing.

                            In normal operation, moving the levers forward engages forward gear at idle RPM. Pushing further forward increases the throttle.

                            The trolling valves are turned on or off by putting the engines in forward at idle RPM and then holding the button down until an indicator on the throttle housing starts blinking quickly. After that moving the throttles forward keeps the engine at idle but reduces the amount of transmission slippage. Bringing the throttles back to idle RPM and pressing and holding the button again deactivates trolling.

                            I'm sure that it is great for fishing but I really didn't like it when I tried using the trolling valves when docking.

                            Cheers,
                            Jim V.

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