Back Flushing your outboard up the pee hole

[Bigplumbs]

I have a quite old Mariner 2 stroke 60 hp outboard that is the best engine I have. Like many old outboards (this one is 1998) stripping it down is sometimes not wise as bolts can be shall we say a little seized and you can snap them and finish up in a worse state than where you started.

Just lately the tell tale is a little weak so I replaced the impeller/water pump. It was still just as weak with the new impeller and the old impeller looked almost as good as the new. I ran the engine at idle in a tank of water for a reasonable while and I tested the engine block temp with an infrared thermometer and no where was over 50 degrees C. I think the main cooling water is pumping well but there is a blockage somewhere in the tell tale water path. I removed the tell tale nozzle and blew up the pipe and this seemed to help. So I think my theory might be sound.

So to the Question...... If I connect a small pump (windscreen washer size) to the tell tale pipe and back pump some water and flush solution into the engine can I cause any damage. and is this something others have done with any success.

Thanks in advance

 

[Mr Googler]

cant see it would hurt but why not flush solution the whole cooling circuit via muffs?

Blu Thru Boat Engine Salt Flush Complete With Mixer | Boatworld UK

by the time the tell tail blocks up….you can be sure there’s plenty of salt built up further upstream.

 

[Bigplumbs]

cant see it would hurt but why not flush solution the whole cooling circuit via muffs?

Blu Thru Boat Engine Salt Flush Complete With Mixer | Boatworld UK

by the time the tell tail blocks up….you can be sure there’s plenty of salt built up further upstream.

I have seen those systems and muffs leak very bad and you seem to use a lot of solution. I have tried about 4 different types of muffs and all seem to do the same.

The tell tale outlet on my engine is at the very bottom corner of the water jacket, Recently I towed this boat to holiday destinations over 1000 miles and I am wondering if the bumping about and use dislodged the crud and it is now in the bottom of the water jacket. The connector in the botton of the jacket is 90 degrees and is plastic and there is no way I an giving that a turn to find out.

You seem happy to pull things apart with very little worry. I will do that if necessary but I live in fear that doing so will mess up something that is 80 % ok and you wind up at 0 % ok

 

[Mr Googler]

I have seen those systems and muffs leak very bad and you seem to use a lot of solution. I have tried about 4 different types of muffs and all seem to do the same.

The tell tale outlet on my engine is at the very bottom corner of the water jacket, Recently I towed this boat to holiday destinations over 1000 miles and I am wondering if the bumping about and use dislodged the crud and it is now in the bottom of the water jacket. The connector in the botton of the jacket is 90 degrees and is plastic and there is no way I an giving that a turn to find out.

You seem happy to pull things apart with very little worry. I will do that if necessary but I live in fear that doing so will mess up something that is 80 % ok and you wind up at 0 % ok

yes…I wouldn’t take it apart. The blu thru setup is good. Pop the tablets in the mixing bit. Run the engine up on the hose then turn the valve and it starts the mixing process. I used 4 tablets on 275hp verado and the tablets dissolve as it flushes. Lasted about 8 mins which I thought was good. You get 30 tablets I think.

 

[Bigplumbs]

yes…I wouldn’t take it apart. The blu thru setup is good. Pop the tablets in the mixing bit. Run the engine up on the hose then turn the valve and it starts the mixing process. I used 4 tablets on 275hp verado and the tablets dissolve as it flushes. Lasted about 8 mins which I thought was good. You get 30 tablets I think.

Now that actually sounds pretty good. Did it work

 

[Mr Googler]

Now that actually sounds pretty good. Did it work

Mine was preventative but made me feel better so yes ??

 

[JerseyDiver]

Just use hose pipe with a gun fitting and squirt the powerful small jet up the tell tale for 30seconds. Even whilst running this is OK. Failing that compressed air works even better. I use a dive hose removed from a regulator on occasion. Needs must when at sea ?

 

[wombat88]

On old outboards the problem might be caused by aluminium oxidisation/corrosion rather than salt. Makes a nasty gritty deposit. In that case back flushing etc doesn't seem to work. Some form of acid does, with great care...I do not remember its name.

 

[Ribtecer]

All of my outboard tell tale problems over many years and many outboards have been in the last part, ie the tube from the block of the engine to the outlet on the cowl.

A simple 150mm of copper wire or strimmer cable left inside the cowl is most useful for clearing the blockage.

Frequent flushes are very important.

 

[Bigplumbs]

All of my outboard tell tale problems over many years and many outboards have been in the last part, ie the tube from the block of the engine to the outlet on the cowl.

A simple 150mm of copper wire or strimmer cable left inside the cowl is most useful for clearing the blockage.

Frequent flushes are very important.

I hear you on that one

 

[Pleinmont]

All of my outboard tell tale problems over many years and many outboards have been in the last part, ie the tube from the block of the engine to the outlet on the cowl.

A simple 150mm of copper wire or strimmer cable left inside the cowl is most useful for clearing the blockage.

Frequent flushes are very important.

Yes my Honda used to get spiders, salt crystals and stuff regularly blocking the tell tale - poking a length of strimmer cable up it used to get the stream going again in a few seconds