Caution Merc 200 - 250 EFI owners (2-stroke)

Discussion in 'Boats and Motors' started by ErieAngler, Mar 31, 2008.

  1. ErieAngler

    ErieAngler Still Deadly w/ The Net

    I just learned this over the weekend as I discovered my problem. Those with the stated motor, mine is a year 200 225 EFI, on a jack plate may have this same issue.

    The lower unit is cooled by the water and being on a jack plate may not allow it to cool sufficiently. The result is the oil heats up, expands and pushed the water pump housing up into the impellar housing. This ruins the seal on the water pump and impellar housings and allows water to get into your lower unit. It also ruins your impellar as the upward pressure pushing on the plate below the impellar ends up "eating up" the impellar from the bottom, drive shaft center outward.

    If you have such a motor, you may want to check it this year before you hit the water. Merc makes a non OEM water pump to solve this problem from happening again.

    Merc has this listed as a service "issue" for the motor i mentioned.

    Thought I would pass this along.
  2. ncraft150

    ncraft150 Buckeye-Basser

    Actually problems can occur with any motor on a jack plate possitioned to high. One of the main things to watch when adjusting your jack plate height is water presure to make sure your getting enough cooling.

  3. Champion188 Elite

    Champion188 Elite Smallie slayer

    ncraft150 is right on! Not only the Mercurys suffer, ANY outboard that is ran in to high of a position on a jackplate will suffer this problem.
    Every boat with an outboard should have a water pressure gauge,if it doesn't,install one quick they are CHEAP insurance.
    Rule of thumb is never let the water pressure drop below 12 PSI at WOT also watch that it doesn't drop off while making a sharp turn.
    I have run a Merc 200 EFI for the past few years with NO problems,I change the water pump/impellar every 2 years and try to maintain 15 psi.
  4. Isn't there also an aftermarket tube that can be installed that helps keep the water flow pressure up where it needs to be, especially for motors that are jacked high?

    How much does it cost to change a waterpump/impellar? I know that is on my short list of things to do on my "new to me" used bass boat................ per the guy I bought it from.
  5. u can get the impellar kit for around 50 bucks not that bad to do...helpful links on my post from about a week ago check em out