Page 1 of 2 12 LastLast
Results 1 to 10 of 13
  1. #1

    Help me choose my first PWC - clearing weed clogs, Seadoo iDF important?

    I'm 53 and will be doing 99% 2 up riding. Most of my riding will be Sanibel, Pine Island, Marco and some Keys. Mostly near shore but may get brave enough to do a long run with seat time. I have narrowed my choices to

    1. FX Cruiser for size and stability not speed
    2. GTX 170 for stability, storage plus the new IDF feature

    How often would the IDF come into play during a normal day on the water?
    I have no clue if riders have to do this a couple of times a day or very seldom.
    If this is a seldom used feature then I am leaning towards the FX Cruiser

    Last edited by K447; 03-22-2021 at 09:30 AM. Reason: Title clarity

  2. #2

  3. #3
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    near Toronto, Canada
    Quote Originally Posted by FLORIDA_MARCUS View Post

    How often would the iDF [Intelligent Debris Free) come into play during a normal day on the water?
    I have no clue if riders have to do this a couple of times a day or very seldom. ...
    We have ridden PWC for more than a decade. Many different models, several brands. Until the iDF feature become available just this model year, all PWC riders had to manage weed/grass clogging risk without being able to reverse the engine water flow through the jet pump.

    Note: Reverse mode on all jet pump watercraft without iDF does NOT turn the impeller in the reverse direction. Reverse mode simply deploys a curved bucket behind the jet pump rear nozzle, redirecting the water flow forwards at angles. The water is still being drawn into the intake grate under the hull in the same manner as when going forward.

    The majority of times when the jet pump intake became clogged with weeds or grasses occur when one accidentally (or perhaps overconfidently) rides into an area with dense weeds or grasses. Open water, sandy beaches and well traveled waterway channels are unlikely to cause a clog. Depending on where you ride and what the weed/grass density is, you could potentially ride for the rest of your life without ever clogging the jet pump.

    Even in riding areas with known thick weed patches, once you know where they are and don’t ride right through them, I expect most riders on most days would not once be stopped by weeds.

    We sometimes ride for several days in areas with miles of shallow water with plenty of weedy areas. The really dense weed patches we call ‘salad bowls’. On those days I may need to dismount and manually clear weeds several times, or not once.

    With the hull running at speed and on plane the jet pump is only skimming a few inches below the water surface. The fast turning impeller can chew through quite a lot of weed material and pump it out the back.

    Tip: If you notice the weed density has suddenly increased, immediately and firmly increase engine power and hull speed. Look for a less weedy area and steer towards it. Sometimes the speed and minimal depth of the water intake is enough for the weeds to not fully obstruct the water flow and the thrust continues. You ride right through the weedy area and keep going.

    Some weeds may be snagged in the intake grate. As you continue riding these may break apart and flow through the jet pump. You may notice moderately reduced thrust, then suddenly the jet pump burps out the weeds and 100% thrust is restored.

    The problem occurs when the grasses accumulate against the intake grate vanes and (mostly) block the flow of water to the impeller. Jet pump thrust is greatly reduced, the impeller is starved for water flow so it cavitates (engine revs very high but almost no forward thrust occurs) and the hull quickly slows down.

    Stop the engine immediately once you lose all thrust. The jet pump flow also provides water to cool the engine and exhaust. With a clogged jet pump, you do not want to overheat the engine.

    How to get the weeds away from the intake grate?
    For non-iDF watercraft, some of the techniques include;

    Stop engine. Stand up and firmly rock the hull side to side. The more energetically the better, side to side, rapid back and forth motion. Under the hull this creates water flow across the weed mass, hopefully working it loose. Do this until clumps of weed material appear, floating up from under the hull. Keep rocking some more. If you are lucky, enough weed material will have loosened and drifted away that the jet pump can clear the remaining when the engine starts.

    Are you still floating in a dense weedy patch? You may need to paddle yourself to clear water.
    Tip: Since you have a paddle, paddling backwards with vigour can also help loosen the weed clog, perhaps combined with more side to side rocking.

    Here is a trick that can work, but it requires a second running watercraft, a moderately skilled operator, and both hulls must be in an area without dense weeds (paddling may be needed). Bring the two hulls together, rear to rear, so the jet pumps align. The disabled engine must be with off the reverse bucket fully raised. This is the default for Yamaha RiDE but requires a command sequence on Seadoo with iBR.

    The running PWC, with the rear very close to and inline with the disabled jet pump, suddenly accelerates directly away. The huge jet pump thrust forces water backwards through the clogged jet pump, hopefully dislodging the weed mass from the intake grate. Might have to repeat the process a couple of times.

    Sometimes there is no getting around it, someone is getting into the water. We ride with the expectation that we are going to get wet, and there is always the possibility of being ejected into the water while riding. We do not wear street clothes on PWC. Always swim wear and often a wet suit.

    Floating alongside the hull, engine off and lanyard removed, position yourself where the jet pump inlet is easiest to reach. Tip: put a small sticker on each side near the rub rail to mark where the jet pump intake grate is. You are already wearing a well fitted PFD so floating is not a problem.

    With a fully extended arm you reach to the weed clog and start yanking chunks of weeds/grasses out. Pull the material forward rather than just sideways. I have removed weed clumps the size of soccer balls or larger. It can take some effort to disgorge thick tough weed material. Just keep working at it. Most clogs I have removed took maybe a minute to remove, sometimes less.

    If your arm is too short to effectively clear the mass you may need to dip into the water and yank the stuff out with both hands.

    After clearing the clog.
    Reboard the ski.
    Prepare to ride. Gather your thoughts, plan the next steps.
    What direction to ride to avoid another weed risk?
    Lanyard attached to driver.

    Start engine, select forward, test for forward thrust. If some weeds remain, you may have decent thrust but not yet 100%.

    If there is enough thrust to accelerate and get the hull on plane without over-revving the engine, continue riding. Often the remaining weeds will break apart as hull speed increases.

  4. #4
    so yeah what he said ^^^ (great answer K447 as always)

    And FX. :P

  5. #5
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    near Toronto, Canada

    I have ridden these waters many times. Starting about 60 seconds in you can see plenty of weeds just below the surface and in some places thinly spaced reeds extending above the surface. Running at speed the jet pump is able to process the weeds as they arrive and keep going.

    In areas with too much weed density if we were to slow down and allow the hull to settle into the water the risk of clogging the jet pump increases.

  6. #6
    I greatly appreciate your answer!!

  7. #7
    Thank you!

  8. #8
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    near Toronto, Canada
    There are other methods of clearing the intake grate.

    Carry a rope long enough to reach under the hull and up to your hands on both sides. Rope must be tough enough to handle some tension.

    Toss the middle of the rope over the stern into the water, then bring the two ends low and forward along the hull sides. What you are going to do is bring the rope to just behind the clog. Having the grate location already marked on the hull sides helps. A non-floating rope might work better.

    Tension the rope against the hull bottom and start working the rope forward while alternating up and down on the ends, maintaining rope tension. The rope will hopefully catch on the weed mass and work it forward and pull it away from the intake grate. It might take multiple rope passes across the intake grate to get enough of the clog dislodged.

    Tip: Practice this rope method before your first clog. You may find things you need to take into account, like not snagging the ride plate, jet pump or sponsons on the sides. You may need a different type of rope or longer rope.

    If you have a passenger the passenger may need to assist with deploying the rope and may need to work the rope for you if you cannot turn around on the seat.

    On the trailer you can route the rope under the hull and visualize how it might work when in the water.

  9. #9

  10. #10
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    near Toronto, Canada
    If the clog is only partial and I still have some thrust, I may use reverse mode to accelerate reward in a straight line as much as the hull will do. Then kill the engine.

    On a Yamaha this will immediately raise the reverse bucket and allow water to flow backwards through the jet pump and under the hull. Combined with vigorous side to side rocking at the same time often (portions of) the weed clump will loosen and drift out from under the hull.

    I might do this several times until I feel the clump is cleared enough to resume normal riding at speed.

    On a model without reverse mode at all (or not enough remaining jet thrust to actually get going backwards), but still able to move forward at a decent off-plane pace. Do a hard turn left or right, quickly/immediately followed by engine stop, resulting in the hull sliding sideways or slightly backwards through the water.

    Simultaneously perform the same side to side rocking motion as above. Have used this method on multiple older PWC with only forward, no reverse.

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Trying to choose a ski
    By Curious in forum Yamaha Open Discussion
    Replies: 9
    Last Post: 06-01-2014, 11:03 AM
  2. Help me choose my next ski
    By Zack in forum Open Discussion
    Replies: 7
    Last Post: 08-07-2013, 11:09 PM
  3. First ski, newbie, help me choose a ride plate, or shim mine, 760
    By spleecho in forum Yamaha PWC Performance (2-stroke)
    Replies: 6
    Last Post: 06-30-2011, 12:46 AM
  4. Buying another ski, help me choose!
    By urugol in forum Polaris Open Discussion
    Replies: 25
    Last Post: 02-20-2011, 07:17 AM
  5. Wat ski to choose, yamaha or seadoo
    By valk in forum Sea Doo Open Discussion
    Replies: 2
    Last Post: 06-12-2008, 08:44 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts