Yamaha OX66 225s- Tell me everything

[wellcraftv20step]

I have the ox66 250, this is only my first year with it. And since Spare help me get this thing running rite its been a great motor with gobs of power . And everyone I speak with that has one is very pleased with it.. that's all I can tell ya.

[SkunkBoat]

Originally Posted by spareparts

based on a twin F150 repower I just completed, you should be able to buy over 10000 gallons of marina fuel and oil for the price to repower that boat

and by the way, those engines are highly sought after in offshore countries as they are not as fuel finiky as four strokes

Yep I know its a big nut...and I'm a cheap b@[email protected] thought is to run a full year and really decide if going BIG was a good move. If I decide this is the boat for the next 15 years then...

Factors for repowering-
Really can't stand the smoke
200 four strokes would probably double the mpg...canyon trip 100 gallons vs 200 gallons...over 15 years that is a big number to help offset repower$.
These are 17 years old so they will require constant repairs, some nickel and dime(just ordered an oil tank pump) and some not so cheap..
That means more down time and this is a big boat/no trailer...$$ and hassle to pull to work on.
Likely that at some point I will be forced to repower anyways so I might as well do it early.
These running motors are worth something to sell right now to lessen the hurt of repower.

Factors against-
from a total $ perspective its only worth it if I keep the boat for 15 years or so.
Have to tell wife I'm spending $35K on motors

[phatdaddy]

And, being able to sell running 2 strokes better than trying to get rid of non running 2 strokes

[THEFERMANATOR]

You will not double your milage unless you troll ALOT, and I do mean ALOT! The fuel economy diffetence for long runs is no where near as much as most think it is. At idle to low load situations, yes, you will see a big jump, but at cruise to wot the realistic improvement should be in the 10-25% range of improvement. I currently havea 4 stroke because that is what was on the boat I found I liked, but I would have just as easily have gotten one with 2 strokes. If you're after mpg, then a direct injected 2 stroke will most likely beat out even the 4 strokes in most areas.

As to hating the smoke, have you tried a better quality oil like pennsoil synthetic blend? Yamalube is a good oil, but I had the least amount of smoke with the pennsoil. Also make sure the oil injection pumps are adjusted correctly. Even 1 turn out of adjustment can make the difference between smoke or no smoke. I had a 25HP Suzuki YEARS back that fought me fouling plugs, ended up being the pump was 2 turns out of adjustment. It actually fell within theallowable limit, but adjusting it dead on cleared up all the smoke and no more plug fouling.

[SkunkBoat]

So checking things out, running different battery switch positions its clear that the port engine is not charging and wont run without a battery. Gut reaction is Rectifier/regulator. Anyone know if there is a fuse in that circuit?

[spareparts]

its not supposed to run without a battery,

two big fuses and a spare under the back cover on the port side of the engine, Yamaha engines have two charging systems, nice to use if you have a separated house battery.

https://www.google.com/search?q=ox66...d1-Sduze4rOrM:








.

[SkunkBoat]

so I replaced the rectifier (without really troubleshooting cause I am a dummass). rectifier didn't fix it. So measured the stator (green wires) 0v AC....open resistance between all 3 green wires...looks like stator....

anyone know if you can pull that flywheel with a steering wheel puller?...don't have the yamaha tools for that.

hoping I find a fixable broken wire cuz its $600 new and $150 used and used is a crap shoot.

[SkunkBoat]

36mm socket wrench- $20 AutoZone
Bolt-type wheel puller- $14 Harbor Freight
18" by 1/2" breaker bar wrench - $10 Harbor freight

Pulled flywheel and yes ..stator has broken wires.
Debated used on ebay $140 or new at Boats.net $593...went with new.
Waiting for part...

[SkunkBoat]

Originally Posted by spareparts

its not supposed to run without a battery

I don't want to seem like I am doubting you, just asking for a little more info...

We figured since it has an emergency pull start rope, that it should run without a battery...so we tried it and it shut off...
Then we turned off the battery to the running Stbd engine and it kept running...

after that we read the warning on the switches "Don't shut off while engines running"

did I mention I don't have battery switches on the V20 and was just winging it. Had been running them on BOTH which caused the uncharged battery to drain the charged ones when I left the switch on Both overnight....new boats!!!

I think the PO had some inkling as to a charging problem because all 3 batteries were brand new and he had both Stbd and Port Aux charging wires to the port battery.

[SkunkBoat]

So new stator and regulator gives us 14.5 volts DC unloaded, which is nice.