mercury 3.3 and brick cleaner

[timv]

there is no water coming out of the tell tale on my tender's outboard so I have flushed it through with brick cleaner. After about an hour there was some spitting and eventually a steady stream although on a number of occasions it blocked again before clearing itself. Thinking I had cured the problem I revved it up a little and it appeared to block again just spitting at first but now all I can get is a jet of steam out of the tell tale. My question is - is this just it blocking up again and I need to persevere or have I damaged the impeller ? I am able to blow down the pipe and create bubbles in the bucket so its not fully blocked and the steam is certainly under pressure coming out of the pipe.

many thanks
Tim

 

[jimmy_the_builder]

Why not just pull the impeller and have a look at it?

 

[tico]

More likely to be the cooling passageways in the head clagged up with corrosion products.
The cooling passages are pretty small and block easily.
Its not that difficult. Head off and scrape out the gunge and replace. Gasket set from e-bay.

 

[dustywings]

Why not just pull the impeller and have a look at it?

Yes, it's quite easy and I think there is a video on YouTube showing how to do it, it's exactly the same as the later four stroke small engines.

 

[TQA]

It almost certainly AINT BROKE so DONT FIX IT.

The Mercury / Tohatsu 3.3 is notorious for blocking it's pee hole.

Step one with the engine running check to see if water is coming out the vents on the leg just above the prop. You may need to tilt the engine a little. The water will appear as a spray along with the exhaust gases. If you see the spray the engine is getting cooling water.

Step 2 Poke a bit of wire up the pee hole. You can do this with the engine running and there is no need to remove the side covers. Poke away until you get some flow. Repeat as required. In most cases you will get normal flow after 1/2 an hours running.

Replacing the impeller on the 3.3 IS NOT A TRIVIAL EXERCISE.

It is located on the main drive shaft just above the gear box. It is normal for the retaining bolts to be difficult to remove through corrosion. But the real fun comes when trying to refit the leg to the powerhead. Getting the bits to line up is very fiddly. It is possible to do it singlehanded in the cockpit but easier with a helper and on a waist level bench with a vise if you have access to an OB mechanic I would let him do the job.

NB A lot of cruisers either use a 3.3 or keep one as a backup. If you don't use it for month expect the pee hole to be blocked. This seems to happen even if you run it in fresh water before storing it.

 

[[164147]]

Why on Earth would you use brick cleaner to flush an outboard?!

 

[jrudge]

Presumably as it dissolves calcium

 

[MrB]

Presumably as it dissolves calcium

It dissolves aluminium too.

 

[volvopaul]

Why on Earth would you use brick cleaner to flush an outboard?!

Its aggressive but it does work, it's ok when duluted with water , rydelime is a lot kinder to metals.

 

[[164147]]

It dissolves aluminium too.

Exactly

 

[timv]

many thanks for all the advise.One more quick run in the brick acid solution was enough to get it peeing in a stream I would myself be proud of these days !!