Engine Boggs down after 4400RPM'S and starts to cut out

[Fish Tales]

I have a 1998 Yamaha 225 HP Ox66 Engine that Starts to bogg down after 4400 RPM and will drop down and cut out until you pull the throttle back. Engine will also shut off completly after coming down a hard wave. Engine always starts up and runs after it shuts down.

Third problem I keep finding water in the engine oil reservoir have drain main tank and monitor the oil I put in as I use a clear container to make sure I don't see water in the oil before it goes in the main tank. Water seams to come in slugs thats why I don't think it's condensation build up. Engine is on a 98 228 Grady White boat.

PS I have had a lot of problems with this engine since I boutgh it new. Original block blew up with 546 hr on engine. New blok has around 800 hours and low compression on one cylinder.

Thank's in advance for any assistance in trouble shooting my problems the boat has been in the service yard for two weeks and with Yamaha service center they still can not identify the problem.

Fish Tales

[jb123]

well if you consistently have water injected into your block that one wont last long either. i would suggest moving the aux tank as it is getting water somehow and also replace all lines as there may be one cracked and sucking water from puddling water.
as for the rpm drops, have you checked/cleaned/tested the 02 sensor?
you will also wan to break down your vapor tank, clean the filter inside it and replace the tank oring when reassembling as your HP fuel pump is in there and you do NOT want to replace that one.

[1d10t]

Sounds exactly like a bad mechanical fuel pump.

[Fish Tales]

Gentlemen
The cause of all of my troubles have been worked out. The reason I was getting water into my Engine oil Reservoir was the vent hose was inserted into the water drain hole on the bottom half of the engine cowling. When the boat would be in the water the tank would suck water in as the oil was drawn down. I raised the vent tube and the problem stopped.

The problem with the engine shutting down when the throttle was increased turned out to be Clogged fuel Injectors. According to the Mechanic that did the repair all the injectors were completely clogged and the engine would shut down due to having to much air and no fuel "Flame Out" good thing it was a boat and not a Airplane.

Thanks to all for your recommendations. I hope my problems help someone else trouble shot similar problems they might have in the future.

Thanks
Fish Tales
Santa Cruz