I hate to say it but it is not a matter of if, but when will a powerhead blow. Some motors blow at 100 hours, some motors blow at 5,000 hours. Basically, powerheads blow when something causes one of the pistons to freeze up and the resulting built up pressure causes it to crack the head.How do you blow a power head? Not trying to be a smart ass just want to take care of the engine I have now. Avoiding pitfalls or other peoples past mistakes will help me avoid costly bills I can't afford. Thanks!
Ding. Ding. If I am understanding you correctly, you ran the motor, something felt off but you continued the run the motor until it blew? Not to get preachy, but big cause of outboard failure is to ignore the signs. When it doesn't feel or sound right, don't run it.I drove the boat a week before it blew. Something was definitely off with the motor. It felt like it was not running on all six cylinders. When the motor blew, you could see clear through the crankcase. From the photos of the heads it was most likely cylinder detonation.
Tdub. Good advise on how to run the motor. I don't hit the lower WOT for at least 15 minutes on the morning. Rarely do I push my motor to the high WOT limit. You are right about people knowing only two speeds. It's an expensive lesson.[/QUO
How is the motor we rebuilt for you last year running?
We ...Tracker ATX rebuilt 8 or 9 Merc's last year with just 1 repeat failure and we took care of the customer and had him back on the water in a week or so. Rebuilds can save some money depending on the severity of the failure. If the block is windowed it's less expensive to get a re manufactured rotating assembly. Regardless of which way you go the root cause of the failure must be identified to avoid a repeat. Fuel injectors, air injectors and oil pumps and so on must be serviced.
I currently have a 250 Pro Xs rebuilt with new rings , bearings and one new piston. Fuel and air injectors have been serviced as well. This is a drop on and could be installed and running in a couple of hours. This is a power head that I built as a spare for me but will sell if someone needs it. This motor is on a stand and can be run if you would like to see it.
DO NOT FORGET TO DETERMINE THE ROOT CAUSE......
Either way, sorry to hear about it. i have been there a few times. I know this sounds like an old man but I am a firm believer that an outboard will stay together much longer if you do 3 things. 1)Let it warm up, it takes longer than you think. 2)Stay out of the gas and off the rev limiter. The guys that know two speeds (idle and WFO)seem to have the most problems. 3)Find a good shop and perform, by the book, routine maintenance
What's a good general recommendation for how hard to run a motor? During the first hour of the break in period on mine, the manual recommended keeping the RPMs between 4000 RPM and 5750 RPM with RPM changes at least once every two minutes.Tdub. Good advise on how to run the motor. I don't hit the lower WOT for at least 15 minutes on the morning. Rarely do I push my motor to the high WOT limit. You are right about people knowing only two speeds. It's an expensive lesson.