Outboard 'tell tale' problems

[wombat88]

I have a Suzuki DF50 whose tell tale is weak and intermittent but I never get overheating alarms.

What is the name of the stuff that one puts into the cooling system to dissolve bits of corrosion etc and where do you put it? Is it a good idea or does it tend to make things leak?

The boat is afloat so having it lifted and running it in a bath of vinegar (???) is really not an option!

 

[Boathook]

When the tell tale reduces flow or stops on my outboard, I poke a thin bit of wire into the hole to make sure that it is clear. It doesn't take much muck to cause a restriction from little bits of seaweed to salt crystals.

 

[wombat88]

Yes I've done the wire thing a few times to no avail. Tempted to forget about it but know I shouldn't.

 

[PaulR]

suspect you are thinking of rydlyme

 

[wombat88]

suspect you are thinking of rydlyme

That name rings a bell, is it a good idea or does it run the risk of making things worse?

 

[wombat88]

Reading the instructions looks like I'd have to lift the boat...which I want to avoid if poss.

 

[WF36]

Assume impeller is in a good state?

 

[JerseyDiver]

If you can get to a hose pipe. Use a gun fitting and squirt into the tell tale to back flush. You may get a bit splashed if not on target. As other have said it may just be salt or weed etc.

 

[Boathook]

Yes I've done the wire thing a few times to no avail. Tempted to forget about it but know I shouldn't.

If you have done that, check the impellor as mentioned by WF36 in post 7. That will possibly mean lifted out as most impellers are in the gearbox. Normally the tell tale seems to be at the beginning of the cooling system and just indicates that the pump is working.

 

[Fire99]

I've had tell tale issues in the past and it is worth taking the tell tale hose off the engine and pouring water through it to check there is flow. I've had one in particular that I put wire up etc but when I tried to pour water through the hose, very little came out the other end.

Also carefully give the engine-side connection a little poke too (carefully). The engine outlet can get a little gunged up too.

 

[wombat88]

Impeller replaced this winter. I've tried the hosepipe back flush. Interestingly it worked for an hour or so (not particularly strong) then the tell tale dropped away. There is something floating around in there which needs to come out...somehow!

Tho cooling system is working, she ran for about 4 hours between 3 and 5k rpm with no bother so it is not overheating, just this infuriating issue with the tell tale.

 

[ChromeDome]

When was the impeller last changed (engine hours)?
Did it get a service at the same time?

 

[Boathook]

Impeller replaced this winter. I've tried the hosepipe back flush. Interestingly it worked for an hour or so (not particularly strong) then the tell tale dropped away. There is something floating around in there which needs to come out...somehow!

Tho cooling system is working, she ran for about 4 hours between 3 and 5k rpm with no bother so it is not overheating, just this infuriating issue with the tell tale.

Could be the whole pump needs replacing. They do wear out and sometimes have faults, some faults caused by the person servicing as I found out last year. If you do the pump body also change the impellor again.

 

[Hot Property]

The tell tale on my Yamaha 25 was intermittent. The impeller had shredded so potentially bits were stuck in the waterways. I removed the thermostat then used a car air compressor to backflush through the telltale pipe with engine running.

Any rubber bits were agitated and released through the waterways.

Now the telltale is doing what it should....

 

[wombat88]

Thanks! Never tried a compressed air back flush. I think I'll work out how to do that efficiently and give it a go.