So I take my boat out for the first time today (70hp 2stroke).....everything is going great. Head out and the boat jumps up on plane and is running great....after about 10 minutes or so I am headed down the river at WOT (probably 45 MPH or so) and all of a sudden my speed decreased to about 10 mph. The motor seemed to not be missing at all.....water from the tell tale was just dripping so I killed the motor and trolled back to the landing. Once back to the landing I fired it up and the motor was running great at idle but I was still just dribbling water from tell tale. Low speed ops were great so.....I trailered it and brought it home - what now?
What year motor is this? WHen is the last time that you flushed the motor with hot water? Sounds like your water pump is is going out cause of the poor discharge. What happened to the RPM's when the motor suddenly decreased speed? There could be several underlying issues here......
Sounds like your motor may have overheated or low on oil and gone into automatic "safe/reduced RPM mode", electronic safety feature designed to protect motors from overheating or low oil. Inspect/replace water pump, thermostat, pressure control valve. If your motor is oil injected, inspect oil tank, pump, etc. Good Luck!
Sounds like your motor may have overheated or low on oil and gone into automatic "safe/reduced RPM mode", electronic safety feature designed to protect motors from overheating or low oil. Inspect/replace water pump, thermostat, pressure control valve. If your motor is oil injected, inspect oil tank, pump, etc. Good Luck!
I talked to my Bro-inlaw last night and he said the same thing regarding the safe mode thing. I am hoping that is what it is. I will first attempt to establish good water flow and take it from there. I recently replaced the impeller and when I first put my boat in the water I checked the tell tale and it was putting out a good stream of water.
If you picked up some trash that covered the water intake while running and starved water pump it would have melted the rubber impeller and maybe the housing, have a look at them.
You also need to check and fix your alarm system if it is not working.
Safe mode retards timing to restrict RPM, that is easy to see with a timing light
Do you have gauges that will signal what alarm comes in?
I found a clog in the outlet of the tell tale - that is the reason I was not seeing a stream of water. I unclogged it and blew back through the water passages in the head and there was no resisitance. I put the ears on it and started it up and I have a good stream of water flowing now.....could this have fixed my problem?
I want to go put it on the water and check it but I am not sure if I will be able to this afternoon.
On the alarms - I have no idea if it has an alarm or not...its my first Yamaha. I think its a 1987 model and its a 70HP 2 Stroke. I have a trim guage, speedo, oil level and tach. Is there a trouble light on one of the guages?
Just got back from the lake. I ran about (now this is a guess) 7 miles or so. The longest straight run was about 3 or 4 miles at WOT. I had NO issues at all with the motor. I had a strong stream of water from the tell tale at all times as well.
Not sure if there is an intermittent problem waiting to rear its ugly head but for now I am feeling pretty good about my motor. Now I just need to take good care of it.
How screwed am I **Round 2**
Linear Mode
