Diagnosis Please ......................

[Hannibal]

Once again, when I think everything is doing good, God mocks me ................... (in jest of course).

Anyhow, went out cruising Satursday. Boat was running great. I eliminated the beeping issue previously posted about and things couldn't have been more peaceful. Did some cruising around 30mph up and down the river before slowing her down to around 8-10 mph so the kids could actually stand up inside the cuddy without much issue.

After doing this for about 20 minutes, we decided to high-tail it back up river for once last cruise through before trailering up. I took her up to about 5800 rpms and trimmed it up and got on our way. About 3 minutes into this - my system check gives me a loud and long beep. I look down at the gauge and the bulb for Check Engine is lit up. I slow the boat way down and eventually kill the motor.

I walk to the back of the boat to look it over and my first go to was the "pee stream" to see how it was doing. It wasn't doing. I was getting a slow trickle with very hot water. I trimmed the motor up and looked for a clogged intake but it was good to go. As such, we sat there for about 30 minutes to let things cool off. Keep in mind - the "hot" bulb didn't light up and I am still without a working "temp" gauge (hasn't been delivered).

After 30 minutes, I started her up and put-putted back to the marina (thankfully we killed the motor just past it). I didn't get any more alarms but still no real water movement.

Once home, I hooked up the flushing ears and ran some salt-away through the motor. Even though I was providing good pressured water, I was getting just a little flow through the discharge hole.

I took a thin peice of wire and placed in between the screen and up through the intake hose towards the pump. I also cleared it out around the discharge output up top. This helped some and where I was getting a steady dribble - it turned into an actual stream. Albeit very weak.

Under normal conditions - if I turned the stream to discharge completely parrellel to the ground, it would shoot 6+ feet before hitting the ground (on the trailer). Here, it was maybe 2' tops.

I am thinking the pump/impeller or thermostat has gone bad. Does this make sense? It hasn't been replaced since I've owned the boat (2 summers) and I am not certain about the previous owners maintenance schedule. I know they say to change them out every 3 years now so it's about time.

Would this make sense in terms of being the likely problem?

 

[miky2884]

I would with no questions start with the water pump.

 

[Bryan 2530]

I would with no questions start with the water pump.

And change out the T-stats while you're at it.

 

[DaleH]

DITTO! Do a FULL waterpump service of impeller, wear plate, O-rings, and drive-key! Plus t-stats.

1st thing I do to any motor (unless bought new), once it passes my initial inspection, is to do a full waterpump/t-stat service immediately, REGARDLESS of when I think it may have been done. To do so otherwise is quite foolish ... and expen$ive ...

 

[Brent]

Does your motor have a pressure relief valve (poppit)? They can go bad like thermostats and pumps

 

[Luv2fish]

Don't know about your motor but I just did my 150 Yamaha and it took about 2 hours in my garage. Very easy repair with the shop manual.

Steve

 

[Hannibal]

Got hold of the marine mechanic and he's pretty confident that it is the water pump/impeller based on what I told him. I am trailering the boat down to him this afternoon. I'd give it a go myself but unfortunately, time is not my friend this week and there is a tournament I am shooting to attend the following weekend. Hopefully it isn't very expensive.

 

[Parker23]

DITTO! Do a FULL waterpump service of impeller, wear plate, O-rings, and drive-key! Plus t-stats.

1st thing I do to any motor (unless bought new), once it passes my initial inspection, is to do a full waterpump/t-stat service immediately, REGARDLESS of when I think it may have been done. To do so otherwise is quite foolish ... and expen$ive ...

Thats my thoughts exactly! Cheap maintance or a very costly repair.

 

[Lucky John]

Whenever I get the water pump done for maintence every three seasons or so they charge me approx 450 which includes changing the thermostats etc. It is not cheap, wish I was able to do it myself.
Once in awhile I might get a piece of eel grass sucked in and it will cause me to overheat.Usually by running the engine in reverse blows it clear and back to normal.

 

[DaleH]

... they charge me approx 450 which includes changing the thermostats etc. It is not cheap, wish I was able to do it myself.

Get an OEM factory service manual and you can do it yourself! Do NOT buy, rely, or depend on those CRAP all-in-one service manuals from Clyner or Seloc - caveat emptor.

A full waterpump service w/ t-stats probably runs me < $100 in parts and 1-2 hours of time ...

 

[Lucky John]

I know the parts are only about 100 bucks, just nervous about screwing it up. Do you need any special tools to do the job?
I am going to do my own oil changes this season as well. Tired of paying 186.00 for a dockside oil change, already bought the pump to remove oil. watched a good video on Sims Yamaha

 

[WAJSKI]

take Dales advice buy the manual for your motor from motor mfg. I can tell you this there is a lot more service you can do than you think using the right manual. The rest of the answers can be found by asking right here on C/P

 

[Brent]

SIM Yamaha site has several informative tutorials

 

[Hannibal]

I definately need a better manual. I currently have a Seloc brand and while informative (as I knew basically nothing prior) - it leaves a lot of questions and uncertainties.

I dropped the boat off yesterday evening and went through it with my marine mechanic. He stated he has three kits of varying stages for the water pump (impeller, shaft, complete) and would go over everything. He said for the water pump, he said it would be under $250 worst case but closer (he thought) to $175-$200. He figured 60-90 minutes to do the work. Much better than $450 that I was thinking.

Best part about it, as I am travelling this weekend (couldn't use the boat), I can swing by and pick it up on my way back as it's usually out of my way (about an hour) and is along the route I am travelling.

I like it when a plan comes together ......

 

[jimjybe]

In florida we service annually replacing the impeller, filters, spark plugs, thermostats, clean O2 sensors and change lower unit lube. Keep in mind that we run all year. Follow the manufactures recommendations and your engine will run better and last longer. A good day of service is much better than a bad day on the water!

 

[Hannibal]

Pump was replaced. She ran like a beauty all day yesterday. We were out from about 530AM til around 4PM and she never as much as sputtered once. That's how boating should be. Couldn't have asked for a better day on the water!

 

[jonas grumby]

You can actually pull up a tutorial on youtube for Yamaha water-pump change out. Pretty easy and a whole lot cheaper to do it yourself. I'm an old grease-monkey and trust my own work/ materials anyway. I'm the only guy on my street that does his own vehicle maintenance not to mention cuts his own grass, all of my neighbors seem to have more money than brains! :lol:

 

[sparky]

http://webpages.charter.net/stephens65/ ... index.html

Good tutorials there.

 

[skipperhub]

You might check the thermostates before you go to the trouble of pulling your lower units. I suffered thru alarm bells, engine running hot and shutting down, pulling the lowers and changing out the impellers etc. I am not a mechanic, I ususallly have my engines serviced by pros and expected more than I was getting.
I never thought about thermostates until a shrimper who is also a great shade tree mechanic told me to change out the thermostates. I did. End of problems.

Capt Hub

 

[Brent]

I agree

We just replaced our thermostats and both were stuck open :shock: