Yamaha water pressure sensor problem

Richard Selman · 20 February 2009, 16:12

Booked my Yamaha F250 in for its first service next Tuesday and the dealer said he has two new water sensors to be replaced under warantee. The problem is something about water passing through the sensor and up the wires. Will get back with more info.

Richard

outboardtech · 20 February 2009, 19:33

WOW richard I havent heard of that recently and I work on Yami all DAY LONG . Thats interesting . I havent seen a Service Bullitine come out regarding that at all ? I will definetly be looking into that one tomorrow Saturday . mmmm

Roy Smith · 20 February 2009, 19:49

We have a 2007 F250 the one with out the water pick up on the skeg
we cant get enough water pressure though the flush muffs which are a double type with a feed in both sides and very good tap pressure, and loads of water comming out of the vents
but we cant get the tell tale to work.
but it works fine once its in the sea.
i flush every trip and we have checked that the water channel is clear , no weed etc. Sorry not hijacking the tread i wondered if its a Yamaha thing.

outboardtech · 20 February 2009, 19:56

I bet you guys if you put that engine IN a BIG bucket of WATER it will pump WATER fine . Ok we have to remember that these engine have a big cooling system and need constant water all the time . Running these size engines on Muffs is NOT helping at all as the amount of air etc getting into the system is alot i promise you . No matter how much water pressure you think you have at that hose and tap its NOT enough for the engine . I have been down this road before and changed impellers , waterpump housings , grommets under powerhead and all it all boils down to is NOT enough water . DROP it in a bucket and see what happens . Baz

Roy Smith · 20 February 2009, 20:28

i wondered why they changed the water pickup on the 2007/8 models
our local dealer as a 250 that the insurance company as written off the leg is fine.
Is it possible to fit the later model lower end skeg to my older model.

Richard Selman · 21 February 2009, 06:50

When I first had the engine I use the flushing connection but even with loads of pressure (I have funky variable speed pump that keeps the whole house pressurised) I could not get any water out the tell tail. I therefore bought a big plastic skip that allows me to run the engine properly submerged. Next time I have the cover off I am going to remove the flushing connection - does not seem sensible to have a part of the cooling water pipework exposed like that.

Richard

outboardtech · 21 February 2009, 09:44

Rich that flushing adaptor on the side of the engine is pretty useful for those guys who have those engines always on the dock and never take them out the water . I have used that adaptor and connected the garden hose onto it .(REMEMBER YOU DONT RUN THE ENGINE ) and just turn the tap on and water will come out the tell tale . I have never heard of the water NOT coming out the tell tale when flushing the engine like that . Maybe there is something more inside this and a blockage somewere but I really cant see this happening especially if you try flush the engine all the time . Last year i reckon I serviced over 50 Yami 150 , 200 and the 250 and never had a cooling prob . Can you send me the serial number of it . cheers

Richard Selman · 21 February 2009, 15:17

6P2/1024026

Tried the flushing connection after the first run of the engine and nothing came out the tell tail. Works fine in the bucket and on the water. Only tried it once. Will try it again tomorrow. Which side of the thermostat does the flushing connection sit - pump side?

What water pressure should I be seeing on idle? - mine sits with only one bar (block not unit of pressure!) on the digital display. I like the network gauges bit it really pisses me off that you cannot get all the readings in engineering units. You can switch voltage between the bar graph and numeric but not things like oil pressure etc.

The tell tail has never been a strong jet even when at normal revs where the display is showing several bars. By contrast, the tell tail from the FT9.9 aux bounces off the drive its so much stronger.

Richard

Roy Smith · 22 February 2009, 11:26

Richard
Mines the same when i look at other engines they have a roaster tail
I worry some times that when i run the engine up at home before towing to the marina as there is no tell tale when using the muffs, How would i know if the impeller is working or not.
Dose the hose flush adapter (with out starting the engine) do the same job at flushing.

outboardtech · 22 February 2009, 15:25

Yes the hose adaptor does the same thing . Just connect it to a garden hose and turn the tap on . To be honest the ONLY thing disadvantage using the garden hose is that is not flushing out the waterpump etc on the lower unit . I have seen the grommets on the water tube corrode away under the powerhead and top of impeller housing due to that salt building up in those areas . SALT IS A KILLER TO AN OUTBOARD MOTOR . Next time you run the engine on the MUFFS unscrew the adaptor on the side of the motor while the engine is running and see if water flows out of there . iT should and that will always give you a good way if your impelller is working properly .

Richard Selman · 24 February 2009, 16:21

Graeme at Mackay Marine showed me the sensor change out notice. Think it was OB-05-09 dated January 09 (was in a rush to get out before the traffic built up). It would appear that they have completely changed the sensor design.

Richard

Blizzard · 24 February 2009, 16:32

They are changing the sensor on a few models, the new one is much larger.

when you get your engine serviced this should get done at your local dealer...

Also I am a fan of the fresh water flush, clears all the salt out of the block pretty effectively, probably better than muff's. Remember NOT to run the engine when using the flush kit.

outboardtech · 25 February 2009, 21:03

ALL models from the F40 - THRU to THE F250 are effected which may have the Cooling water pressure sensor OR the Speed Sensor fitted . Not all engines are effected you would have to contact your Yami dealer and give in your serial number to see if its needs doing . Some models are OK and have had this upgrade done . These models effected are only those that are using the Yamaha Digital Network .

Roy Smith · 05 May 2009, 18:55

still cant get tell tale to work with muffs and i now have a large water butt when full its comes about an inch over the top water inlets and it still dose not come out.
however when in the marina and its fully under the water its works not great but not a dribble.
do you think its water pressure, having to have the leg down 18" under the water, there is an insurace write off engine that i know of
its got the new water pick up dose any body know it its a stright bolt on
i/e new for old, or would that be to easy.