Best muffs for 90’s Johnson 30hp 2T

[Hammy]

As per the title. I have a cheap set of muffs that with a zip tie and some hand pressure works ok, but it’s a very wet experience! Without the right pressure it doesn’t pump water up through the water pump and out the tell tale

 

Are there decent muffs that work well on these engines? 

I have a drum but would prefer the muffs do I can flush some salty captain through it 

 

ta .  

Edited July 5, 2023 by Hammy

[XD351]

I bought one of the ones that feed water in both sides - best thing I ever did !

Edited July 5, 2023 by XD351

[Hammy]

2 hours ago, XD351 said:

I bought one of the ones that feed water in both sides - best thing I ever did !

thanks @XD351 I’ll look them up

[XD351]

If you have access to a bench vise you can bend the steel spring inwards so it makes the fit tighter 

You could also try this on the one you have - saves you a few bucks .

Edited July 5, 2023 by XD351

[zmk1962]

13 hours ago, Hammy said:

As per the title. I have a cheap set of muffs that with a zip tie and some hand pressure works ok, but it’s a very wet experience! Without the right pressure it doesn’t pump water up through the water pump and out the tell tale

 

Are there decent muffs that work well on these engines? 

I have a drum but would prefer the muffs do I can flush some salty captain through it 

 

ta .  

I use the same muffs as XD mentioned above (on a much bigger motor) and they do work. I have had them break where the plastic tubes connect to the flex tubes ... but that was easily fixed by shoving a 3-way hose connector into the flex tubes and securing with cable ties. It's now worked well for years.

But one thing to watch for, is that you should not be relying on hose water pressure to flush the motor. The hose and cups really just need to supply enough water to simulate having the impeller immersed .... and its the impeller that should be generating enough suction and pump head to drive the water through the motor for cooling. If that's not happening then your impeller may be worn and it may be time for a replacement and pump service.

Do you get good water flow out of the tell tale on the water??

If you dont recall then perhaps test it at home by immersing the lower leg in a bucket of water and then run the motor ... if you are not getting a good tell tale flow then your pump is cactus.

Cheers Zoran

 

 

[dunc333]

for a motor that size a collabsable tank (Drum.bucket) available from all good boating stores i reckon would be better hammy for your situation and a rule people often break flushing motor on muffs or drum always keep your eyes posted when flushing cheers dunc333

[Hammy]

2 hours ago, dunc333 said:

for a motor that size a collabsable tank (Drum.bucket) available from all good boating stores i reckon would be better hammy for your situation and a rule people often break flushing motor on muffs or drum always keep your eyes posted when flushing cheers dunc333

Thanks Dunc, yes I’ve had one other motor book itself on the water so I’m paranoid and don’t take my eyes off the tell tale. 

[Hammy]

9 hours ago, zmk1962 said:

I use the same muffs as XD mentioned above (on a much bigger motor) and they do work. I have had them break where the plastic tubes connect to the flex tubes ... but that was easily fixed by shoving a 3-way hose connector into the flex tubes and securing with cable ties. It's now worked well for years.

But one thing to watch for, is that you should not be relying on hose water pressure to flush the motor. The hose and cups really just need to supply enough water to simulate having the impeller immersed .... and its the impeller that should be generating enough suction and pump head to drive the water through the motor for cooling. If that's not happening then your impeller may be worn and it may be time for a replacement and pump service.

Do you get good water flow out of the tell tale on the water??

If you dont recall then perhaps test it at home by immersing the lower leg in a bucket of water and then run the motor ... if you are not getting a good tell tale flow then your pump is cactus.

Cheers Zoran

 

 

Thanks for the info Xoran. It does pump out the tell tàle on the water fine. Just want to make sure I keep it in good condition with good after use care

[Hammy]

10 hours ago, XD351 said:

If you have access to a bench vise you can bend the steel spring inwards so it makes the fit tighter 

You could also try this on the one you have - saves you a few bucks .

Thanks mate, I have a bench vice so I’ll look at that.
 

The ones I have look almost identical to those but with the hose inlet just fed though one of the muffs. We’ve put a zip tie across where you have the red arrows but it still needs some hand pressure at the other end to keep it closed enough. might be a worthwhile test 

[zmk1962]

7 minutes ago, Hammy said:

Thanks for the info Xoran. It does pump out the tell tàle on the water fine. Just want to make sure I keep it in good condition with good after use care

If it pumps fine then you’re on the right track to solve getting water to it. Way back in the day my 40hp johnno used round rubber muffs feeding water from one side and it worked just fine. I may still have a set lying around - where do you live?

With all muffs I’ve had I have had to bend the metal spring arms to provide better compression. Use a vice or just stand on them to close the arms. 
cheers Z

[JustJames]

I know that some on here are fans of the y-type muffs, but it really shouldn't make a difference.  The bottom of the motor is open both sides.  I don't see how having twice as much water come in from one side is any worse than half as much water coming in from each side.

 

What really will make a difference is how well the muffs fit.  But as long as you have sufficient flow to ensure that the water level inside the leg is the same as the level when the leg is in water you're golden.

 

Muffs don't last for over.  As soon as the paint/coating on them is compromised by scratching or rust, they are on borrowed time.

 

If anybody has ideas on why having water come in from both sides would make a difference, I am all,erm, ears.

[XD351]

From what my Yamaha service guy told me , The pumps are not self priming so you need to force water in and up into the pump intake which is higher than the inlet port on the leg . On my motor there is a small hole above the intake port and he said water must be dribbling out of there before I start the motor or it will kill the pump,he recommended the double feed type because with the one side feed water can flow in one side of the intake port and straight out the other and it won’t build up the little bit of pressure that it takes to get the water up to the pump . The double feed pushes water in both sides so it can only go up to the pump , from what I have seen after using the single feed type for 30 odd years and now the double feed type for about a year everything he said is correct . He also added that it was a strange thing with Yamaha engines that inlet port was located on a curved surface making it a little bit harder for the ears to seal .

Edited July 6, 2023 by XD351

[Rebel]

I have the same ones as @XD351 has when I owned a 115hp Johnson.

They work ok.

[Guinness]

You have some absolutely brilliant intel already on this conundrum. The only very basic suggestion I have is to ensure the muffs you use are soft and flexible. I have made the mistake in the past of buying cheap, rigid muffs that can't adequately 'grip' the contours of the outboard's leg. The result is they can't exert enough water pressure into the intake and therefore you won't see the expected tell tale. The muffs made from the softer material are much more effective. Depending on your outboard you may need to adjust the 'fit' of the muffs to secure the required seal but it is a lot easier with the softer material. Looks like you are already pointed in the right direction. All the best Hammy.      

[XD351]

Here is a quick and cheap fix for muffs that don’t seal properly a set of quick clamps - under $10 at bunnings 

Also the elbow broke on mine so i modified it with some poly pipe elbows and garden hose fittings .

as you can see below there is almost no leakage and the water coming out of the side ports is squirting out about 2ft each side where as before it was just dribbling.