Yamaha Warning Buzzer -- Overheating?

[dharris02]

I have a 1994 Yamaha 115 that gives high temperature alarm when I run at high speeds (4200 rpm)-- when alarm sounds, engine starts running rough (as per manual) until it drops under 2000. It acts normal at low speeds...go to high speed and it will give high temperature alarm. Slow down to under 2000 rpm, the alarm will stop after a few minutes. The alarm may sound after a few minutes at high speed, or not at all, or after running some time (i.e. ran 16 miles, one day..no alarm, ran 2 x 8 miles next day, no alarm, ran 18 miles next day, no alarm, ran 25 miles at 4200 and got alarm at end of the 25 miles). Have moved depth finder to avoid cavitation in water pick-up area, changed water pump impeller, changed both thermostats, changed both temperature sensors. I am getting tell tale water stream at all times. The instrument panel still shows in the green (normal operating area) and nothing is flashing. Boat is normally in river water with little operation in salt water...always run boat in river after salt water. Several dealer mechanics have tried correcting. Mechanic says engine is not overheating because he can touch both heads with hands. Approximately 550 hours total on engine. Dealer says it definitely is not oil problem (wouldn't alarm be intermittent if oil?)<br /><br />I have seen a post that bad battery connections can cause activation of the alarm...is it possible? What should I do now? Appreciate any help you can give.

 

[Tom Hamilton]

Re: Yamaha Warning Buzzer -- Overheating?

I have a Yamaha 130 1997 that did the same thing. One "Yamaha" authorized dealer put in a non-Yamaha impeller. Problem continued. After 2 trips to 2 different "Yamaha" repair shops an old guy in Arkansas put in a Yamaha impeller and cleaned out the tubes, water jackets, where ever the water flows around the heads through (I,m obviously not a boat mechanic) and the problem stoped. It had trash in the water ways around the heads and the wrong impeller. Hope this helps.

 

[dharris02]

Re: Yamaha Warning Buzzer -- Overheating?

Thanks for info....I suspect I may have to have head passages cleaned also. Old impellor didn't have any significant wear and I'm getting a stronger tell tale stream than before. I'm read lots of posts to other similar problems, and I'll try two things first. One, I'm on the original battery and connections look ok, but a couple of people have indicated that changing battery/cleaning connections made similar problem go away. It has been a good battery with never a minute's trouble (that I know) but it is rather old. Second, several people indicated that clogged oil filter/bad oil caused a similar problem. I read very carefully owner's manual yesterday and a little note is tucked in there which says 1) overheat and oil alarms are similar (I think that may mean they are same sound on this motor) and 2) that clogged/dirty oil filter problem could give same overheat/oil level alarm except that no red oil trouble flashing on panel. This is what I see...neither temperature or oil trouble indications on panel..always green. If others have had similar problem on Yamaha 115-130 (V-4), I'd be interested in your corrective actions.

 

[richardr]

Re: Yamaha Warning Buzzer -- Overheating?

i am having the same proble rite now high speed buzzzzzzer.
the last time it happen they took off the heads and clean them salty .
after that it ran fine .
richard r

thank you

 

[brewmister]

Re: Yamaha Warning Buzzer -- Overheating?

A sure way to find out if you have a water passage problem is when the alarm goes off pull the cowling off and put your hand on the top of the head.
If you cant leave your hand there you are not getting sigificant water circulation.

 

[bowhuntrrl]

Re: Yamaha Warning Buzzer -- Overheating?

Yamahas are notorious for poppet valve problems. Take yours out and check it. Sometimes they get put in backwards when serviced by unknowing individuals. Also make sure that you have a good thermostat.

 

[Kickass]

Re: Yamaha Warning Buzzer -- Overheating?

heh, here's my problem, this might eliminate some of your problems,,,
I have a 98 Saltwater Series V4 115 TRLW, I have replaced the following:
water pump
impeller
thermostats
temp sensors
poppet valve
the old mechanic I had pulled one of the head covers to check the water jacket, and said it was clean, he did not pull the other one. Soooo, at this point I believe there are only 2 things left, either the other head is clogged, OR maybe it's my TACH is faulty, BUT, I have not looked into the oil issue.
I can tell you this, though, I am tired of taking my boat to guys that say they can fix something WITHOUT water testing it, seems kinda silly, no?

 

[JUSTINTIME]

Re: Yamaha Warning Buzzer -- Overheating?

Kickass
start a new thread

 

[scottfromoz]

Re: Yamaha Warning Buzzer -- Overheating?

f the temp really is up, then how about unbolting the other side's head cover and having a look there (the water gallery holes are very small in parts) and other than that it might require the heads off to look at the water galleries on that side of things. Then there is the exhaust cover to remove and check same under that - although it is not as prone as I understand it to blockage.

Cheers

In my 93 115 V4 a clean of the head cover galleries and the small passages accessible after the head covers (not heads) are removed was enough to get her right again to a constant running of 5,500 rpm - the poppet was blocked and cleaning that didnt help (and Rodbolt doubted it would when I posted about that). It had new thermos, new water pump kit and all looked good...when I took off the head covers (not heads) there was significant blockage of the little 1/8th inch holes that deliver water from the head to the plug side of the heads under the covers - full of sand.

 

[big_b16]

Re: Yamaha Warning Buzzer -- Overheating?

I was able to get a decent feel for whether or not one of the heads was completely blocked by pulling the t-stats and dumping water down each side. If you dump it down the engine side, the water will come out the exhaust...if you dump it down the supply side it will come out the inlet ports. It won't ensure every orifice is open (if there are more than one on the head cover water jacket passage), but it will tell you if they are completely clogged. My issue on overheating was mostly solved by installing a new poppet valve and spring. The valve was alright but the original spring wasn't as stiff as the new style (with the mushroom head valve).