Results 1 to 19 of 19

Thread: Looking for a mechanic in Fairbanks for two 1970-1975 Mercury Jets

  1. #1

    Default Looking for a mechanic in Fairbanks for two 1970-1975 Mercury Jets

    I have 2 50Hp jets on my smokercraft. Both run, but one is having some issues. I NEED HELP!!!

    PM or call 457-1148 in Fairbanks

    Thanks,
    Ken

  2. #2
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    what kind of problems?

  3. #3

    Default

    the motor gets jot at idle. Has new impellers, havent changed the t-stat, or water pump yet.

    This thread is my boat...
    http://forums.outdoorsdirectory.com/...ad.php?t=60847

    HELP
    Moose season cometh

  4. #4
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    oh - I saw that one.

    Still need some clarification - you say it has new impellers but you haven't replaced the water pump.

    It doesn't really have a replacable unit called a water pump like your car does - the water pump is an impeller in small housing.

    So for clarification, what impeller did you replace? The jet drive impeller (big metal thing that you can see when you look in the grate at the jet foot/intake) or the water pump impeller (small rubber thing you have to drop the entire jet housing/driveshaft assembly to see).

    If you haven't dropped the jet to inspect/replace the water pump impeller - that is the easiest answer you can hope for.

    You need to drop the jet and see what you have from there.

    It's not hard and really if you're running rivers up here anywhere but up and down the chena you should know how to do it anyway and have the necessary tools in your boat.

    I'm sure you could get enough guidance right here in the forum to pull the jet, but if you really need help I'm sure someone would be willing to visit you for an evening. I don't have much free time (kids back in school, wrapping up projects before snow flies, etc) or I'd volunteer right away.

  5. #5
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    also never saw an answer to the question someone else asked in your other post -

    do they both "pee" the same or is the problem motor noticeably weaker (or not peeing at all)?

  6. #6

    Default Replaced rubber impellers

    Replaced rubber impellers of both.

    I am going to take the boat to the river either tonight or tomorrow. One motor pees, the other I dont remember if it did or not.

    At idle with the cowling off, you can put your hand on the motor and it gets hot quick, but if you rev it up to 3/4-full throttle, you can feel it cool down right away. That is why I thought PERHAPS it was the rubber gromets on the water jacket (the "ladder") or something else.

    THANK YOU ALL FOR HELP!

  7. #7
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    So in actuality you have replaced the water pump - at least the working parts of it (the rubber impeller) - that's good!

    Are you running it in a test tank or backed into the river? I've seen some of the bigger old mercs take what seems like 30 seconds or a minute to start peeing. But if yours is getting noticeably hot at idle I would be very concerned - definitely do not run it long if it's that hot!

    one tricky thing on the old mercs I've run into is aligning the tube that goes from the water pump up to the power head - for example

    I had one that after taking the water pump apart and verifying everything was in good shape I put it back together and it still wouldn't pee. So I took it apart again to make sure I got the drive pin engaged on the water pump impeller - it was - at the same time I also back flushed from the pisser outlet and verified water moved through the system - it did.
    (the water balloon fill nozzle on the end of a garden hose turned down to low pressure works great - just put the nozzle in the outlet hole and if the system is clear with the jet housing removed you can see the water just pours out the inside of the motor leg - assuming no thermostat which I don't think yours does not have, but I could be wrong)

    So I put it back together again and still no peeing at low rpm - I finally noticed water leaking out from where the jet housing meets the motor leg and realized the tube was not inserted into the powerhead at the top and water was going up the tube then just falling down inside the motor leg to eventually and rather slowly leak out between it and the jet unit.
    I ended up removing the tube from the water pump housing, installing it into the powerhead first to be sure it was seated right, then had someone help by slowly putting the jet housing back on while at the same time I carefully aligned and inserted the tube into the water pump housing.

    But I'm betting your water pump impeller vanes are bent backwards.

    When you did the water pump impeller did you make sure that the impeller was bent the right way? They require some bending/curling of the impeller blades/vanes to fit inside the housing -- if they are bent the wrong direction I've heard that they can sometimes break the vanes off when the motor starts (and they are forced to bend the right way) or like one I worked on recently it had sat so long with them the wrong way that they didn't bend the right way when the motor ran and it just didn't pump well backwards. To verify - first figure which way the flywheel rotates - that is the same way the crankshaft and the driveshaft and therefore the water pump impeller all rotate - Just remember "tips trail" - so the tips of the impeller vanes trail instead of lead as the impeller rotates.

    If it were me - I would take the water pump apart again - while it's apart back flush it to make sure you've got flow (but if it's peeing at higher RPMs it is probably fine) make sure you have the drive pin engaged on the water pump impeller and that the slot in the impeller that the drive key fits in is not cracked or broken out, check condition of any gaskets or block-off plates between the jet housing and the water pump, seal where the shaft goes through, and make sure the vanes are bent the right direction - then make extra sure you've got the tube seated in the powerhead right.

    If no luck there - then the suggestion to remove the water jacket is probably a good one, but just not something I've had to do....yet!

    Really it's a pretty simple system and so an intermittent problem like yours is a little puzzling. That's the main reason I think the vanes are bent backwards - at higher RPM even with them bent wrong they are still enough to make it pee - but at low RPM they just aren't efficient enough to get the water flowing.

    Good luck

  8. #8

    Default

    Thank you again!

    I will try these things. The bad part is that I have to take the boat down to the river (no tanks at the house)
    I will keep you posted!

  9. #9
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    yep I hear you...

    unless you want to double check the problem (peeing or not and at different RPMs) taking it to the river now might not help you

    I woudl tear it apart at home, look everything over - put it back together and drag it down to the river to test.

    let us know how you do

  10. #10
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    Well? Did you get it fixed???

  11. #11

    Default

    Time to upgrade, I live on the Chena and am tired of those old **** Mercs. I hear them 5 miles downriver and another 5 miles upriver. Almost as bad as airboats.

  12. #12
    Member Hoyt's Avatar
    Join Date
    Apr 2006
    Location
    Fairbanks
    Posts
    1,154

    Default

    Quote Originally Posted by KLK View Post
    Time to upgrade, I live on the Chena and am tired of those old **** Mercs. I hear them 5 miles downriver and another 5 miles upriver. Almost as bad as airboats.
    You gonna buy him new ones?

  13. #13
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    you can buy me one too...

  14. #14
    Member rhd's Avatar
    Join Date
    Jan 2008
    Location
    Montana
    Posts
    51

    Default

    Quote Originally Posted by akjw7 View Post
    you can buy me one too...
    Awww... Geeez, I didn't know you guy's needed new ones.

    I woulda ordered a couple extras...
    Attached Images Attached Images

  15. #15
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    sweet! next time then...

  16. #16
    Member
    Join Date
    May 2008
    Location
    Fairbanks, Alaska, United States
    Posts
    184

    Default Did NOT get 'em fixed

    Howeer, a buddy happened to have a 95 65HO Evinrude Jet that he wasnt using and we slapped it on the Smokercraft instead. Had to do some minor stabilizing of the transom just to be saef for towing, but all in all she runs pretty.

    If all goes well I am finally going to go hunting this week for my cow tag across the Tanana. I am about to pee myself with anticipation. Any of you guys have ank first hand knowledge of good moosey spots from the Wood to Salcha? I am thining about the bottom of Salchacket, but dunno.. still searching

  17. #17

    Default

    Quote Originally Posted by akjw7 View Post
    you can buy me one too...
    No Obama will buy you one, with your tax dollars.

  18. #18
    Member akjw7's Avatar
    Join Date
    May 2006
    Location
    Fairbanks
    Posts
    537

    Default

    better than much of what happens with my tax dollars already.

  19. #19

    Default

    I messed up, meant my kids tax dollars. Gotta love socialism!

Bookmarks

Posting Permissions

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