Results 1 to 7 of 7
  1. #1

    Newbie - Sunk my boat week ago - Too late?

    Really hate to ask this question as I am afraid of the answer.

    Have a 97 SeaDoo Speedster with twin 720's. We had a LOT of rain about 10 days ago. The boat was at the dock in a freshwater lake and the bilge pump didn't come on. Result - both engines were under water (including carbs) for I suspect about 2 days. Have been trying to start them for 7 days - cannot get them to start.

    Heres the question I really don't want to ask. Is it too late? Even if I do get the engines running are they just going to fail and do more damage when they fail in the long run? I don't want to finally get them running only to have a bigger mess due to all kinds of rusted messed up parts inside that fail at high rpm or seize to other parts? Or, should I just keep trying to get it running and hope for the best long term and use lots of sea foam? Thoughts? Input?

    Background -
    When I noticed the boat was sunk, I immediately pumped it out, pulled the plugs and turned over the engines. As expected, LOTS of water came out of all the plug holes. However, I was not able to start. I have spent HOURS over the last several days trying to get the engines to run. Both engines will fire briefly on 1 cylinder, but not both. I am afraid I am going to burn out my starter with all the cranking I have done. Have had to charge the battery numerous times due to running it down. I put some alcohol in my gas, I have removed the carbs, but still getting a lot of water vapor on both front cylinders that are keeping those plugs from firing. I have the boat in a heated garage with fans and a heat lamp aimed at engines and I am getting ready to spend a few more hours cranking. Sure wish I could find an easy access drain at the crank level!

  2. #2
    wotxxxsd's Avatar
    Join Date
    May 2012
    When your done cranking and they won't start fog the engines with oil to prevent rust.

    Did you empty the air intakes?

    Hard to say once they run if they will stay running with no issues..

    Have you compression tested the motors?
    I believe they are 720 cc and very reliable..

  3. #3
    wotxxxsd's Avatar
    Join Date
    May 2012
    Welcome aboard the Hulk!!!

  4. #4
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    near Toronto, Canada

    If water got into the fuel tank, then you need to drain the contaminated fuel out. Engines will not run if the carbs are getting water instead of fuel!

    Alcohol added to the fuel will not help unless the amount of water in the fuel tank is minimal. Too much water and adding ethanol makes it worse by causing phase separation. If you had ethanol blended gasoline in the fuel tanks to begin with, and water got in, the fuel is probably separated and not usable. Drain, clean, add fresh gasoline.

    Once you got most of the water out of the engines, that is when the rust accelerates due to the oxygen in the air. Fogging oil sprayed as much as possible into the air intakes and the spark plug holes will slow the rust process down, but not stop it.

    You need to get the engines running not only to get them warmed up but also for the air flow going through the engines to dry out the internals. The combination of heat and air flow is what is needed.

    As you have probably read by now, the key is to get the engines running, then take it to the launch ramp. Back it down while still fully strapped down front and rear, until the jet pumps are nicely submerged. Start and run the engines. You can apply throttle while observing the engines.

    Only take the boat off the trailer when you are confident it is going to continue running. No need to get stranded on the water.

    Once the engines have been run under load at speed, nicely warmed up and dried out internally, fog them thoroughly and shut them down. That is about all you can do.

    Have you inspected the electrical system for water inside? Connectors and electronics do not work well when wet.

    WD-40 was originally designed to drive moisture out of wet electrical gear, such as distributors and coils. WD = Water Displacement
    There are other products of course, but WD-40 is available everywhere.

  5. +1 by:

  6. #5

    Join Date
    May 2012
    McKinney Texas
    One tip I just read is that what prevents a wet engine from starting is that water gets in the spark plug and shorts it out. If you cut off the part of the spark plug coming from the side to increase the gap of the plug is will reduce the chances of water shorting the plug.

  7. #6
    Well, - news not so good. Starter sounds like it is starting to go and I am hearing grinding while cranking - not sure but sounds like a bearing. Suspect there is still a lot of water in the bottom end as I can still see a heavy mist coming out of the engine when it cranks. I did manage to get 1 running, but the other is being a stubborn #%@!#. Guess I should probably pull both engines and go through them before everything rusts together on the inside.

    Thanks for the tips guys. Some good advice.

  8. #7
    leejax01's Avatar
    Join Date
    Apr 2011
    Clean the carbs from water etc. and put them back on. Get some fresh plugs. Pour some premix in the cylinders to get it going. I have seem 720 engines sit longer and come back.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. My boat
    By INDY27 in forum Other Toys
    Replies: 46
    Last Post: 01-09-2017, 12:43 AM
  2. Bought my GPR 2 weeks ago and
    By GP1300RnPVB in forum Yamaha Open Discussion
    Replies: 20
    Last Post: 08-06-2007, 11:01 AM
  3. Sunk my Ski HEEELLPPP
    By Kinchyle in forum Sea Doo Open Discussion
    Replies: 49
    Last Post: 04-24-2006, 05:56 PM
  4. sunk my rxp
    By godfather in forum Sea Doo Open Discussion
    Replies: 22
    Last Post: 11-15-2005, 12:06 PM
  5. Nav lights for my boat..Cause we can do it in Canada..
    By two2curupt in forum 4-Tec Performance
    Replies: 15
    Last Post: 09-26-2005, 10:26 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