Weak water at tell tale not always your impeller

[Bigplumbs]

At the end of last season the last use of the rib was in Poole Harbour staying on a camp site up the frome River. On our last trip we had to come back at low water which is at lease 2 miles I would estimate. I am sure I sucked in mud to the cooling system of the outboard as we started having problems.

At the end of last year we had the thermostat fail and I also replaced the impeller as I was having pumping issues. I also flushed the whole outboard with Rydlyme which seemed to work well. At the end of last year the motor was pumping water very well. Fast forward to the start of the 2023 season and she would only just dribble a few drips from the tell tale. Knowing that the impeller was good I suspected that residual gunk left in the engine would have settled at the low point which is where the impeller pipe is connected.

I followed some advice from a thread way back on here to blow some compressed air up its pee hole pipe. This seemed to work a dream.

As I said in the title a weak tell tale flow is not always your impeller. Video below

Hopefully this might help someone else and even save them a few quid

 

[Hot Property]

Yes the air compressor trick up the telltale outlet on the block is a good method.

I had a shredded impeller on a Yam 25 I'd bought. Took off the thermostat and cover, hosepipe up the leg in the pump delivery pipe, air in the little telltale union. The air agitates the rubber bits and it all comes out of the thermostat housing....

 

[Bigplumbs]

Yes the air compressor trick up the telltale outlet on the block is a good method.

I had a shredded impeller on a Yam 25 I'd bought. Took off the thermostat and cover, hosepipe up the leg in the pump delivery pipe, air in the little telltale union. The air agitates the rubber bits and it all comes out of the thermostat housing....

Now that is a good tip also

 

[Bigplumbs]

Took the rib out for a nice run today and she pumped water very well at the tell tale..... As I got back to the slip it had reduced somewhat..... but still OK. I think once you have this mud/silt in the engine it is not that easy to get out. More air to be blown up soon and run it a while just with the open ended pipe to flush out as much as I can. For some reason Mariner decided that on this engine you would not be able to take the front of the water jacket off

 

[spannerman]

It doesn’t always pay to flush from below, many outboards have water channels with 90 degree bends at the top of the water pipe in the stem and impellor bits get trapped there, much better to reverse flush pushing the bits out the way they came in.

 

[stelican]

At the end of last season the last use of the rib was in Poole Harbour staying on a camp site up the frome River. On our last trip we had to come back at low water which is at lease 2 miles I would estimate. I am sure I sucked in mud to the cooling system of the outboard as we started having problems.

At the end of last year we had the thermostat fail and I also replaced the impeller as I was having pumping issues. I also flushed the whole outboard with Rydlyme which seemed to work well. At the end of last year the motor was pumping water very well. Fast forward to the start of the 2023 season and she would only just dribble a few drips from the tell tale. Knowing that the impeller was good I suspected that residual gunk left in the engine would have settled at the low point which is where the impeller pipe is connected.

I followed some advice from a thread way back on here to blow some compressed air up its pee hole pipe. This seemed to work a dream.

As I said in the title a weak tell tale flow is not always your impeller. Video below

Hopefully this might help someone else and even save them a few quid

I think that is common knowledge that you get restriction in that pipe, Pointless blowing back into the system.

 

[Fire99]

Good one.. Telltales are notorious for getting blocked, especially if used in salt water environments.. It's a pretty tiny hole (especially on small outboards for tenders) and warm salty water quickly turns into a gooey paste in an outboard cooling system. I've had to unblock a few for people over the years (much to their happiness as they thought the engine had a serious issue)

 

[Bigplumbs]

I think that is common knowledge that you get restriction in that pipe, Pointless blowing back into the system.

The restriction was not in the pipe it was at the bottom of the cooling jacket on the engine. What I did was not pointless at all. It was a very cheap and incredibly quick way of confirming that the impeller etc was all working well and that the engine had cooling water pumping around

 

[Bigplumbs]

It doesn’t always pay to flush from below, many outboards have water channels with 90 degree bends at the top of the water pipe in the stem and impellor bits get trapped there, much better to reverse flush pushing the bits out the way they came in.

Yes indeed I think pushing it out the way it came in has got to be a good idea. Which ever way you look at it though once you get silty mud in there it is not easy to get out especially when on this engine you can’t seem to remove the cover to the main cooling jacket