Telltale blocked... should I be able to blow through?

[alt]

Hi Folks,
Yamaha 200 HPDI.... was p1ssing out water lovely yesterday. Today, a few drops at approx 1500RPM, nothing at idle.

Most likely just blocked rather than impeller, however I noticed at idle that the starboard (telltale side) block gets hot at idle (Can still touch, but it's hot) whereas the port side is cold.

I tried pumping a little air to reverse flush the telltale, but not a hope... can't suck or blow on it... is this normal?

We'll take the RIB out later to see if there's water coming out of the exhaust before pulling the leg, but thought i'd ask on here first.

[Keanaz]

Originally Posted by alt

Hi Folks,
Yamaha 200 HPDI.... was p1ssing out water lovely yesterday. Today, a few drops at approx 1500RPM, nothing at idle.

Most likely just blocked rather than impeller, however I noticed at idle that the starboard (telltale side) block gets hot at idle (Can still touch, but it's hot) whereas the port side is cold.

I tried pumping a little air to reverse flush the telltale, but not a hope... can't suck or blow on it... is this normal?

We'll take the RIB out later to see if there's water coming out of the exhaust before pulling the leg, but thought i'd ask on here first.

Put some white vinegar or expsensive Salt away through it - leave it 24 hours then a full flush with fresh water

[Orwell boy]

Personally i never leave port without a piece of largish suare strimmer cable ,usually works !!

[alt]

So, we whipped off the gear-box. The impeller looks good (no missing bits), but we'll replace it anyway.

Shoved a hose up the water pipe and it comes out the exhaust, but not the tell-tale.

Tried again to put compressed air up the telltale but it's totally blocked (compressed air was just expanding the tell-tale hose).... this is after we removed the tell-tale hose from the plastic 'p1sser' (this is the most likely thing to get blocked).

It appears water is NOT getting to the starboard head of the V6.... at idle it gets hot whereas the port side is cold.

Any idea where we should start looking next?

[alt]

Forgot to mention... engine had been laid up for a year. We launched yesterday on fresh water and tell-tale was fine, went for a 1 hour run (plenty of WOT) and no problems at all. It was only when I started her today I noticed no water from tell-tale.

This has just happened out of nowhere... weird.

[paddlers]

Sounds like a chunk of something has dislodged internally. Have you had the thermostats out and had a look at the condition internally.
I usually flush with a few litres of white vinegar in the tub for 5 minutes then a good flush for 10 minutes with clean water after a couple of weeks in the sea . On occasions there has been an immediate improvement in flow especially with the smaller outboards .

[alt]

Got sorted.... salt / calcium blockage.

Had to take the black tell-tale hose off from the block and ram is through with stiff wire... half the pipe was clogged.

Took off the thermostat and started with hot water for quite a while. Then blew it through with air. then re-circulated vinegar for a while (collected in a bucket and in through the thermostat housing.

Just a heads up incase anyone finds themselves in the same situation.

(I will have my friend flush through with Rydlyme ASAP)

[paddlers]

Nice one. I'd give it a really good flush in a tub of fresh water , give it a few revs to see if anything else is loose and get rid of any vinegar in the system.

[alt]

Originally Posted by paddlers

Nice one. I'd give it a really good flush in a tub of fresh water , give it a few revs to see if anything else is loose and get rid of any vinegar in the system.

We're on fresh water (But previously she was a salt water engine).

Dunked her and brought her for a run earlier today. All seems good (didn't spend too long at WOT). Tell-tale temp seems fine (warm, not too hot). I will check with an IR Thermometer soon but for now all seems good.

I still suspect there's a bit of a blockage in the starboard head. I use Rydlyme on my Volvo KAD engines (but by-pass the impeller).... does anyone know (or any experience) of using a de-scaler in a bucket and running the engine? (Therefore, being pumped by the engine impeller)

[jeffstevens763@g]

Originally Posted by alt

We're on fresh water (But previously she was a salt water engine).

Dunked her and brought her for a run earlier today. All seems good (didn't spend too long at WOT). Tell-tale temp seems fine (warm, not too hot). I will check with an IR Thermometer soon but for now all seems good.

I still suspect there's a bit of a blockage in the starboard head. I use Rydlyme on my Volvo KAD engines (but by-pass the impeller).... does anyone know (or any experience) of using a de-scaler in a bucket and running the engine? (Therefore, being pumped by the engine impeller)

i use citric acid

[willk]

RydeLyme is weak brick cleaner (6-9% hydrochloric acid). I use citric acid to shift scale on steam generators.

[jeffstevens763@g]

Originally Posted by willk

RydeLyme is weak brick cleaner (6-9% hydrochloric acid). I use citric acid to shift scale on steam generators.

how will hydrochloric acid affect internal paint coatings on outboards?

the reason i use citric acid is i keep marine fish and use it to clean pumps of crud build up [salt]

[willk]

Originally Posted by jeffstevens763@g

how will hydrochloric acid affect internal paint coatings on outboards?

the reason i use citric acid is i keep marine fish and use it to clean pumps of crud build up [salt]

I have no idea! Alts use of Rydelyme in the Great Bog of Galway will be to remove limescale - probably in the heat exchangers. Salt deposits respond well to Citric Acid, the active ingredient in Salt Away. I assume where there is caking to remove, neither product would do any harm if used according to the directions?

That said - a lot of cleaning products ARE quite aggressive, and those eager beavers who use them to OCD levels are going to have a different outcome to the "once it's filthy" brigade.