8hp Mariner - water flow problem

Discussion in 'Bubba's Outboards' started by Thommo, Mar 16, 2007.

  1. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    G’day to you all out there. Now I have a little problem which I need some advice on. I acquired an older 8hp Mariner which hasn’t been used for approx 8 years. I did the right thing and pulled the spark plugs lubricated the cylinders etc and pulled it over a few times – all good. I took the leg off and checked the water pump – all good. Time to see if it will run. Using a pair of muffs I gave it a couple of pulls and it started straight off.

    Problem; there is only a dribble of water out of the pisser. I took the leg off again and attached a water hose to the pipe which comes from the pump still no real water.

    Question – how do I clean out what I assume must be a blockage in the block?

    Any advice appreciated.

    Regards – Thommo

    From Tasmania; way down under.
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Good morning and welcome Thommo.

    Not run for 8 years? Replace that impellor in the pump first off, before one of the blades breaks off and seriously clogs the block. When you get a new impellor, you'll see the difference between it and the old one.

    You can use compressed air to back blow the passage from the pisser and have it in a barrel/bucket of water, not on a hose. When you blow it out, you should see a strong burst of air in the water coming up from the water intake.

    You could also use a fine stiff wire to probe into the pisser hose to possibly clear the blockage before using the compressed air.

    Good luck and let us know how it works.
     

  3. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    Thanks Bon - appreciate your sugestion. I will give it a shot and let you know the results.

    Regards - Thommo

    From Tasmania; way down under
     
  4. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    That's Bob not Bon - sorry fingers got stuck on keyboard:)
     
  5. waterwalker

    waterwalker New Member

    Messages:
    604
    State:
    Louisville Ohio
    Welcome mate, glad to have you on board. Now my friend I know that BOC is international.
     
  6. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    Yep - look out we Assies are taking over the world:)

    No catfish down here though but still plenty of action on the water. Winter coming on so things will slow down somewhat; even with nothing between us Tasmanians and Antarctica we don't get the severe weather you would get in Ohio.
     
  7. peewee williams

    peewee williams New Member

    Messages:
    3,111
    State:
    Pembroke,Georgia
    Welcome!Always the best of advice from Bobpaul.I am only sticking my nose in here as I owned a special order very long extended shaft 8 HP.Mariner for use in very rough water to keep the prop from breaking out as my boat broke over waves.My 20 inch shaft 40 HP.primary motor was just too short in the shaft dept in bad water.It was bought and used in the South East Atlantic ocean and rivers.My water flow had slacked off after about 2 years and I took it by the dealer to get a water pump put in while I waited as I had never changed on in a mariner or Yamaha as I had been told it was.The mechanic was a childhood friend who came up interested in nuts and bolts as I was.The Motors water passages had grown up with sea water deposits.He cleaned out what he could and ran it.I started using it on a small boat in our swamps and rivers which have black water from the tannic acid of rotted vegetation.In two years of heavy use,it was CLEAN inside.Unbelievable but true.This was a 50 mm X42 mm,164 cc engine.This was around a 1980 engine,give or take a few years.I still have the book but Don;t know where the receipt is as the motor was stolen from me.I am only adding this as you did not state the age of your motor.My book states "Do Not operate outboard while flushing".in the hose flushing instructions.I just used a bucket on a block with a water hose running into the bucket.I could run it this way.This motor was a great kicker and also a great small boat fishing Motor for a boat with a extended transom.I love you Brothers and Sisters.peewee
     
  8. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    Thanks to you all - for what it is worth the outboard is a 1986 model. It has had little use; I would estimate 50 hours total. Most of its use was in fresh water with the occassional run in salt water.

    I will get a chance to replace the impeller today and give it a blast of compressed air so hopefully I will be able to report results tonight.

    Regards - Thommo
    Tasmania way down under
     
  9. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    They also make a product called salt away and I don't know if you can get in Australia or not but it is real good for cleaning out motors from the inside while running in a barrel
     
  10. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    Well folks I have replaced the impeller which set me back $A59 (about $47 US) which I thought was excessively expensive anyway it has been replaced. I went to the gas station and blasted air backwards through the pisser put it all together and fired it up - no water at all. I tried it with the muffs and also in a bucket.

    So I took the back plate off the water jacket at the back of the motor. There was next to no corrosion/salt; there was some sand which I have flushed out.

    As it is getting late I don't think the neighbours would appreciate me firing it up now so will have to wait until morning. If it still dosn't work I guess I will have to take it to the experts which is probably what I should have done to start with LOL.

    Hang in there I will advise the outcome:)
     
  11. peewee williams

    peewee williams New Member

    Messages:
    3,111
    State:
    Pembroke,Georgia
    We are eagerly waiting on a solution with you.That is how we all learn and help each other on here.Sorry that you still have a problem.My 8 HP.had a "Above prop"exhaust.You can remove prop.and shear pin first.You should be able to stick a 3 or 4 foot long small hose a little ways up the exhaust,lower the motor in a bucket of water and crank the prop less motor in neutral.The exhaust coming out of the hose should be wet with water.If not,you are not getting cooling for some reason.If it is steaming enough to feel hot,you are not getting the proper amount.I do not know if this can be done with a through prop exhaust.Don;t give up.A large piece of trash can act like a check valve,allowing you to blow in to the water outlet,but not out.Water pump impellers have been installed with the key missing or such."The obvious is easy"."No one needs much of a mechanic for that"."The off the wall is when you need to be able to think".I went nights to a State run Outboard Motor School Trade School for 40 HP.and under Outboards around 1970,but never worked it as a trade.The instructor often stressed this.Old but great advice.I wish you the best,and we have some great mechanics on here thinking with you.They are handicapped solely by not having their hands on it.I wish you the best and am hoping to hear good news.I love you Brothers and Sisters.peewee
     
  12. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    Well Bobpaul, waterwalker, bubbakat, peewee and others I am happy to advise of some success.

    The pisser now dribbles.

    After replacing the impeller, blasting with compressed air and poking thin wire up the outlet I can report I (no the outboard motor) has a dribbling pisser (LLOL).

    I know that the pump is pumping as I am getting plenty of water through the prop and the motor is not overheating. I ran the motor with the muffs and threaded about 8 inches of mono filament up the outlet. As I suspected I dislodged a fair amount of sand (see previous comments) so I guess we have a gut full of river sand inside somewhere.

    As I now have some action and am happy that the motor is getting water my next step is to take it onto the water and give it a good thrashing. Unfortunately I doubt I will get a chance for a couple of weeks or more.

    Fear not I will report back to the forum.

    Thanks for your input - John

    From Tasmania; way down under
     
  13. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Can you disconnect the pisser tube from where it comes off the block? Try cleaning it there.

    If there's a thermostat cover, remove it. Engines can be run for a short period of time with a thermostat out and the cover off to flush the sand.
     
  14. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    No the pisser appears to be a copper or brass press fit into the block. I will try adding a photo; Pisser.jpg
     
  15. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    No didn't work - administrator tells me I have to have 10 x posts before I can add attachments and he also tells me I only have 9
     
  16. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    Photos seem to be working now. Here is one of the water jackets. I was able to remove the rear one however the one on the port side has 2 x frozen bolts. The last thing I want is to shear off a bolt because that would be expensive.

    water jackets.jpg
     
  17. psychomekanik

    psychomekanik New Member

    Messages:
    2,534
    State:
    Illinois
    Here's an idea that might work now that your getting some water out of it. try backflushing it while it's running. blow air through the pisser with the engine running. the water will help dislodge it and pass it through.
     
  18. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    Thanks - I am going to give it a good hard run maybe this weekend if not it won't be until after Easter. If it doesn’t clear itself with the run then it is back to the drawing board with your suggestion being one of the first things I will try.

    BTW I did get the side water jacket plate off only breaking one bolt during the process. The language was frightful and the neighbour’s kids hide:) I was lucky that it was one of the top ones so could drill it out and re-tap the hole – alls well that ends well. What did I find – river sand, so that reinforces my thoughts that the pisser is blocked with some sand.

    Thanks all for your input – hang in there I will advise the outcome.

    Regards Thommo

    From Tasmania; way down under
     
  19. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Drilling out those S/S bolts is a pain. For badly corroded ones, I use an acetylene torch to break corrosion. The only torch I've seen that can do it.

    It's not recommended for a first timer to use on aluminum. I practiced on alot of junk motors and saw aluminum disappear with that much heat. In some of the smaller bolts, there just is no other way than to break them.

    Good to see things are looking up for you. Look forward to reading the outcome.
     
  20. Thommo

    Thommo New Member

    Messages:
    19
    State:
    Tasmania, Australia
    Well I said I would report back - I took the motor/boat for a good thrash today; performed exceptionally well however that damm pisser only dripped but I know it is pumping heaps of water. Provided it keeps dripping I am confident all is well.

    Regards

    John

    From Tasmaina: way down under