durban removes defletor tubes in 90hp 1984

[durban]

last week i found the one thermostat in my m8ts motor not working , replaced it & the port side was still getting hot then took the cylinder head off & found the deflector tubes closed up with salt & were hard up against the cylinder head gasket i couldn't see any water coming from there so i took them out & threw them in the bin , assembled & started again letting idle for nearly 2hrs , the motor was running sweet as & no over heat

 

[Haffiman]

Re: durban removes defletor tubes in 90hp 1984

Would not be surprised if next posting concerning this engine will be:
Durban threw away a melted regulator and replaced it with one from a VW Beetle!!

 

[durban]

Re: durban removes defletor tubes in 90hp 1984

with the salt build up over the years around the tubes it causes a restriction of water flow in that area , it was also found that on the port side outer left side around the sleeve on the bottom cylinder no water was getting there , between the pipe & aluminum salt had built up & gone hard cutting it off from water circulation .

 

[Haffiman]

Re: durban removes defletor tubes in 90hp 1984

Running without deflectors, might even just use cut rubber hoses, ruins circulation. All water takes shortest way, and that is NOT the proper way.

 

[durban]

Re: durban removes defletor tubes in 90hp 1984

to me it does not make any sense to have kept the pipes in , because the chamber that fills with water around the sleeves come from 2 little holes where the pipes fit onto ,aswel as from the top & bottom by the sleeves removing the pipes the water is still gonna fill that area irrespective pipes or no pipes either way , for my application in sea water i think ive solved a potential headache , salt build up in that area

 

[Haffiman]

Re: durban removes defletor tubes in 90hp 1984

Perhaps you are right and the designers at OMC have done it all wrong for some 40 years? Wish you friend all the best.

 

[emdsapmgr]

Re: durban removes defletor tubes in 90hp 1984

The factory service manual has a nice explanation and flow diagram regarding the purpose of those rubber deflectors and how they contribute to even block cooling. You should get a copy and read through that section. You'll understand Haffiman's comments better.

 

[Chinewalker]

Re: durban removes defletor tubes in 90hp 1984

to me it does not make any sense to have kept the pipes in , because the chamber that fills with water around the sleeves come from 2 little holes where the pipes fit onto ,aswel as from the top & bottom by the sleeves removing the pipes the water is still gonna fill that area irrespective pipes or no pipes either way , for my application in sea water i think ive solved a potential headache , salt build up in that area

It's not a matter of filling the area with water, it's directing the flow to avoid hot spots. The water has a definite path it must take so that it removes heat properly. If the water gets too hot where it enters the circuit, it will not remove heat later in the pathway. The "potential headache" is dealt with by replacing the deflectors when they become an issue, not removing them... That's what maintenance is.

 

[durban]

Re: durban removes defletor tubes in 90hp 1984

i under stand what you on about k , whether hot water goes out through a pipe that leads into a hole or the hot water goes out through the hole without the pipe either way it still goes out that's my way of thinking , should this motor over heat , then i will come & shake your hand .

 

[Mas]

Re: durban removes defletor tubes in 90hp 1984

letting idle for nearly 2hrs , the motor was running sweet as & no over heat

Do not get too excited yet, as you know, there is a big difference between 2 hours of idle vs 2 hours WOT.

I would stay near the shore on this one.

Mas

 

[Faztbullet]

Re: durban removes defletor tubes in 90hp 1984

Durban's next post: my m8ts motor not working cylinders scuffed for no reason.

 

[CaptainKickback]

Re: durban removes defletor tubes in 90hp 1984

Replace the deflectors, unless you can invent a suitable replacement.

BTW, does Durban flush his engine after each use???????

 

[Haffiman]

Re: durban removes defletor tubes in 90hp 1984

Been reading the original post a couple of times over and over again:
'found the deflector tubes closed up with salt & were hard up against the cylinder head gasket i couldn't see any water coming...'. I might be coming of age, but deflector TUBES with water??
Then further down:
'between the pipe & aluminum......'.
Not sure if the engine or Durban is Frankenstein in this case?

 

[Joe Reeves]

Re: durban removes defletor tubes in 90hp 1984

Error, cancelled

 

[boobie]

Re: durban removes defletor tubes in 90hp 1984

Joe, just remember, it's his mtr, not yours or mine. Thank God.

 

[durban]

Re: durban removes defletor tubes in 90hp 1984

has any one run the motor without them , if no , then no one knows , i will be the first one to learn something good or bad , who knows

 

[Haffiman]

Re: durban removes defletor tubes in 90hp 1984

Yes, I've been in that situation after a customer melted 2 regulators in a rather short time.
Finally I removed the heads to check water circulation just to discover previous owner of the engine had done a 'Durban' with the deflectors!! On top of that he had disconnected the temp alarms.

 

[Joe Reeves]

Re: durban removes defletor tubes in 90hp 1984

Error, cancelled

 

[jbjennings]

Re: durban removes defletor tubes in 90hp 1984

Durban,
I've got a neighbor that totally rebuilt a '76 johnson 35hp, and it wouldn't run right for him. He said he'd ran it a few times, and the last time it powered down and just wouldn't run right at all. I told him I'd take a look at it. I tested the compression immediately right in front of him and saw that one cylinder was about 120, and the other was about 65. I took off the head and guess what wasn't there? No water deflectors. He didn't know what they were, and the engine borer either removed the old ones, or they had melted out in a previous overheat. Either way, it had overheated again due to no water deflectors and ruined an expensive rebuild.
I would urge you, as others have done, not to take them out of your friends motor. It will NO DOUBT ruin it for the reasons already posted.
Good luck,
JBJ

 

[durban]

Re: durban removes defletor tubes in 90hp 1984

before i go any further i make a final decision , do the pipes stop before the cylinder head . because when i took the cylinder head off they were hard up against the gasket it could be that the salt lifted them couldn't see any water coming or going in the pipes & if they are to sit below the gasket face then it tells me that water can go into the pipes & then back to the center between the the 2 blocks or come from there were the water is fed from the impeller because if this is the case i dont see a need for the pipes . because without the pipes the water can go through the same hole the pipes fit to