Yamaha OX66 225s- Tell me everything

[SkunkBoat]

Originally Posted by spareparts

good solid engines, basic efi. They like gas though. If you want to get ahead of the curve and get it all ready for next season. Plan on doing some off season maintenance to them. O2 sensors are easy to clean, remove from housing, heat till cherry red with a map torch, let cool off and reinstall. Make sure to clean the passage into the cylinder and the little barbell thing with merc power tune or parts cleaner of your choice. Yamaha sells the gaskets needed as a kit. Replace thermostats, be care full, those little bolts break off easy. Replace water pump impeller, use yamaha factory kits only. If it doesn't have a water separating filter for each engine, install one(new fuel hose doesn't hurt). If you're up for it, take the vst(fuel tank assembly on the engine) apart, clean it out, replace the screen on the fuel pump. While its off, check or replace the mechanical fuel pumps. Tighten the bolts holding the pumps together, there are three of them. If you think you need diaphragms, check the price on the whole assembly, they're not much more than the rebuild kits. Run good fuel, good oil and ring free and you should have good service out of them. Items of note, they only run on four cylinders at idle, so don't get freaked out of it seems like they aren't hitting on all 6, they aren't. Trim motors and fuel pumps are very expensive from yamaha, the aftermarket is supplying good alternatives for them now.

thanks!

[bgreene]

Friends with em ' tell they burn a LOT of fuel and a LOT of oil.

Outdated technology and performance.

[THEFERMANATOR]

Originally Posted by bgreene

Friends with em ' tell they burn a LOT of fuel and a LOT of oil.

Outdated technology and performance.

Outdated technology I'll give you, outdated performance is a big negative IMO. I know DFI's run good, but it's tough to beat the performance AND lighter weight of the old school 2 strokes. And the 225 ox-66's were true beasts utilizing the larger displacement block of the 250's. So yes, they use 5-10% more fuel and probably 25% more oil than a DFI in an average outing, but they do have there benefits to many boaters still.

[SkunkBoat]

OK so we've run them a bit now.

had to replace a thermostat housing (cracked at bolt and dribbled very slightly)

Stbd engine tops out at 4600. Port over 5000. Prop on stbd had work done, maybe problem???

Rpms/throttles match up until 4000, then stbd has to be pushed farther than port.

Both at 4200 she hums along at 33 mph/33gph and sounds great. Had it up to 38mph.

best fuel burn at 25 mph/22gph.....ouch!!!! (has yammie fuel flow meter)

tilt position sensor on stbd not working...haven't investigated yet.

Stbd fuel pumps look brand new.

HATE the blue smoke. Haven't had a 2 stroke since 2003. You really get used to breathing....

LOVE that the boat was easily worth $22k without any motors so I can't complain about running motors.

Hope to run these next year and scrape and save and beg and borrow to get new 200 yammie or zuki I4 four strokes in the future. That'll last me right to retirement....

[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

[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

[Kracker Jack]

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

Yea but they only have to run 2 miles off the beach to be in the pelagics!! Lol!!!

[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

so I've been calculating it out...ignoring maintenance of 17 yr old motors...

Low price for gas at dock - $3 gl
Low price for 2 stroke oil - $.40 per gl of gas ($20gl oil/50gl gas)...Pennzoil $20gl...Yamalube is $50gl
---- low price of fuel $3.40 gl

Canyon trip burned 220 gl for 3 hrs out/3 back /4 hrs running around and trolling 220/ 10 = 22 gph

Expect to run 100 hrs /season = 2200 x $3.40=$7480

Lets say 4 strokes knock it down to 15gph x 100= 1500gl...x $3.40=$5100

Lets round it to $2400/year fuel savings

Pair of zuki 200s- $34,000/10 years...$3400/year- $2400/year fuel savings= $1000/year for new 4 strokes


If gas higher=more savings
if run more due to more canyon trips= more savings
If keep boat more than 10 years= more savings

spending money SAVES money! I wonder if my wife will buy that