New Yami 60HP 4S EFI - FLushing

[Spaniard_King]

For those with 50 and 60 yamies they dont have popet style thermostats and will not be opened by water pressure alone.

99% of engine have the flushing port feeding the water pump side of the block, hence this backfeeds the water pump. If you run the engine when using the flushing port there is no flow of water through the water pump and you risk overheating and damaging the impellor and melting the housing.

Even tho the flush port may clean most of the engine the only way to ensure the best possible flushing is to use the muffs and run the engine or if available back it into a freshwater dam

[TheRealAndy]

FWIW, the merc 50 we have on the yacht club rescue boat, the manual says to run the engine on idle when using the flushing port.

[spelchek]

I don't have a yammi to see how they are set up but please get the yammi mechanics to explain how when using the flush port with the moor running the impeller isn't spinning dry?

I think some mechanics need to be careful with their advice and go the extra step and say that if port flushing then they should not have motor running depending on size and brand?

For what it's worth, I was specifically told by the dealer on delivery of the new boat NOT to use the flush port with the engine running.

[spelchek]

For those with 50 and 60 yamies they dont have popet style thermostats and will not be opened by water pressure alone.

What about a 40 yamie, SK?

[Spaniard_King]

Not %100 certain on certain late model but I doubt they would have changed the cooling path too much, near all of the yam 4 strokes have standard thermostats and they all would have a popet releif valve which does not allow water flow to the regions beyond the thermostat

[WalrusLike]

SK I appreciate any words of wisdom you can supply.... On my Yammie 115 2stroke....

Should I wait till the telltale warms up? Or is it ok as mentioned above?

[Spaniard_King]

Walrus,

When you have an opertunity take the engine cowling off and run the engine on the muffs, at the top of each cylinder head towards the rear of the engine will be a cover plate with 4 bolts in it (each side) this is where your thermostats are housed... after 5 mins of iodling these should be warming up if they are not then you most likely have thermostats which are jammed open not allowing the engine to warm up... if this is the case get the thermostats serviced

Your tell tail is being fed water from the supply side of the cylinder block and should never be hot

[WalrusLike]

Ah... Great stuff SK, many thanks... Will do so as soon as I can.

I appreciate the advice you just gave me, and all the other good advice I have read of yours on here. Many thanks.

[Splash]

Damn, I just use the hose port with the motor running, how much damage have I done in the last 7 years.

what condition was your impellor after a service?

splash

[Spaniard_King]

Spalsh the Impellor is not a true indication of the actual condition of the pump. The housing needs to be inspected as when the housing has been melted it usually allows air to be drawn in to the cooling system. This is mopst evident at higher rpm where the actual water flow drops off and will start to cause over heat situations. The tel tale may still look good at idle.

[Splash]

interesting - thanks sk.

is the housing plastic?

splash

[TheRealAndy]

Straight from the horses mouth. I enquired about my 50hp Yammie.

Thank you for contacting Yamaha Motor Australia with your question.

We can advise that both systems of flushing are recommended in your
owners manual. The TOP flush allows you to clean the internal cooling
passageways of debris and salt residue quietly in built up areas.
While the traditional method of using ear muffs is as effective at doing the
same task but allowing you to run your motor (noisy), which some owners
prefer to do.

We suggest that should you operate in high silted areas or an accidental
grounding on a sand bar occurs. Then "Top" flush first, the higher pressure
from most taps help to remove any build up, debris etc.
Then follow on with a 5 minute flush with the ear muffs to ensure system is
cleaned and no blockages have been caused.

Just to quickly summarise, both procedures or combination thereof are
recommended when flushing your motor.
It is really a matter of the operators preference and location that determines
which they will use.

Once again, thank you for contacting us, we hope this brief explanation
is of assistance.

[Dan5]

Good work Andy..........Thats in a "round about" way what we were told by our local dealer..........use both methods to flush allthough their answer still really is not definitive on wether or not top flushing alone reaches the lower leg unit.

I have seen plenty of silt/sand trapped up in that top flush port on theses engines aswell.........enough to block the flushing hose at times.

Dan


FWIW my Suzuki manual recommends using the muffs to flush the water passages........but this is Suzuki and not Yamaha ofcourse.

[spelchek]

Thanks Andy and SK.

SK - is there a specific area I should be asking my dealer to check (to see if I have any/potential problems with using the flush port alone) on it's next service? Every service it has come back with good reports wrt it's general condition. I've never needed an impeller changed (but I do have them changed regardless at every service).

[Splash]

Straight from the horses mouth. I enquired about my 50hp Yammie.

No mention made of having the motor running or not whilst using the TOP flush method??

splash