Yamaha F115 issues

[rusty0369]

So, here's the story. I did the compression test. 1-4 90, 172, 178, 175. Hooked led to each injector lead, all are flashing. Come to find out, the A hole who owned the boat before me put 17 hours on it and never got over 2500 rpm. He bought it brand new. Bad deal on seating rings. He also didn't winterize it at all, bad for fuel system.

At this very moment it's sitting in driveway running on a mix of 5 parts gas to 1 part sea foam and is blowing out some God aweful crap. Holding rpm at 2k for next hour. She's spitting but getting better every min. Going to increase by 1k every thirty minutes till I get to 4k. Then gonna go to lake and run the **** out of it.

I will be installing a second 1 gallon tank in this boat so as to do this very thing before winter every year and anytime I feel she needs a dose.

 

[charleso]

Hopefully you don't have a damaged/broken piston ring. Definitely consider investing in Yamaha Ring Free or other quality ring free product. Fingers crossed that this will finally resolve the issue for good.

 

[rusty0369]

Final driveway run before going to lake, all cylinders now reading 152 to 154 PSIG. Bore scope on cylinders show nice and shinny new look. Fuel pressure holding steady at 42.6PSIG. Engine is smooth and silky. Will run out to lake tomorrow after work with high hopes.

To all who have offered advice, thank you very much. This has been one hell of an ordeal.

 

[charleso]

Sounds great. All this time, I wonder if the shop you first took it to even considered doing a compression test? At least you have spare injectors if you do have any future problems. The buildup you burned out of that cylinder could have been from ethanol, a sticking injector(from ethanol), or an improperly seated ring from not breaking the motor in. Let us know how she does on the water.