Yamaha OX66 or F225

[Heyspike]

In my search for my Seafarer I have come across 2 motors. The bullet proof OX66 and the 4 stroke F225 on several models.
The 2 boats in question: 1 has 900 hours on the OX66 and the other 750 hours on the F225..
In doing some research about the motors, the OX66 with regular maintenance will last a many more hours but the F225 seems to have many issues. Exhaust corrosion and others.
Should I run from the F225 and go with an OX66 or are both good and I am reading too far into it? Just doing my research before I drop 20k on a boat.
Thanks,
John

PS- I've done a few searches but the data is 8 years old plus.

 

[Jonah]

I have 2012 F225s, so am replying just to 'watch' this thread and see what others say in response. I know nothing about the OX66s, except for all the positive comments I've read on this thread in the past.

 

[SirGrady226]

In my search for my Seafarer I have come across 2 motors. The bullet proof OX66 and the 4 stroke F225 on several models.
The 2 boats in question: 1 has 900 hours on the OX66 and the other 750 hours on the F225..
In doing some research about the motors, the OX66 with regular maintenance will last a many more hours but the F225 seems to have many issues. Exhaust corrosion and others.
Should I run from the F225 and go with an OX66 or are both good and I am reading too far into it? Just doing my research before I drop 20k on a boat.
Thanks,
John

PS- I've done a few searches but the data is 8 years old plus.

I know the OX66 is a work horse and many are still in use, only down side would be economy, from what I have read they are very thirsty compared to the more modern 4 strokes..

 

[Doc Stressor]

You should have any used outboard checked out by a mechanic before you put down cash. Or you can do it yourself if you're handy.

While the OX66 is reliable, they do eventually blow up as the result of age and lack of use. It's internal corrosion that can cause a bearing to spin or a wrist pin to let go rather than the parts wearing out. I've also seen them fail as the result of fuel system issues. If fuel is restricted or one of the carbs gunks up, a cylinder will run lean and overheat. But if they are well maintained and run frequently using good fuel they can last for 20 years or so.

There is really nothing wrong with the F225 except for the dry exhaust corrosion issue. Engines made after late 2007 do not seem to have the problem. In any case, it's not difficult to detect before it gets to the oil pan where catastrophic engine failure can occur. You just remove the lower unit and look up inside the exhaust tube with a lighted borescope. If you see pits forming, you have the problem. Salt crystals in engines used in saltwater are to be expected and are not an issue. There are lots of pictures of exhaust corrosion available online.

Personally, I would never go back to a 2-stroke engine. I've been a 4-stroke guy since 1998. I hate the noise and stink of a 2-stroke when I'm on a friends boat. Plus, you realize at least a 30% increase in fuel economy vs a non-direct injected 2-stroke.

 

[seasick]

In my search for my Seafarer I have come across 2 motors. The bullet proof OX66 and the 4 stroke F225 on several models.
The 2 boats in question: 1 has 900 hours on the OX66 and the other 750 hours on the F225..
In doing some research about the motors, the OX66 with regular maintenance will last a many more hours but the F225 seems to have many issues. Exhaust corrosion and others.
Should I run from the F225 and go with an OX66 or are both good and I am reading too far into it? Just doing my research before I drop 20k on a boat.
Thanks,
John

PS- I've done a few searches but the data is 8 years old plus.

What year motors are you looking at ( F models)? I have less concern for motors manufactured mid 2007 and later.
I also agree with Doc. There are many upsides to 4 strokes, for me the biggest is the noise level and depending on the wind direction, the smell of the exhaust. I don't completely agree about the borescope being a definitive test for corrosion in the oil pan. Yes, seeing the pitting is not a good sign, not seeing pitting is not a 100% guaranty that there is no corrosion.
If you come across F225s that have had the exhaust kit repair done and that can be proven, I would feel a lot better about buying the earlier year F225s.

 

[Heyspike]

Unfortunately I don't think my budget will allow me to get a 2007 or newer. My year range is 2000-2004 Seafarer.

 

[SkunkBoat]

OX66 will suck gas. My twins net me 1 mpg @ 30mph. They stink. But they GO!
I went for the 2000 boat with the OX66s because the 2004 with F225s was priced $30k more.
Assuming you do end up needing a repower sooner rather than later, you didn't pay up for 4 strokes that are almost as old.

 

[Another Distraction]

ox66!

 

[SkunkBoat]

Don't get me wrong, I hate 2 strokes. I would much rather HAVE 4 strokes. But I'd rather buy new ones than pay up for 15 year old ones.

If you're planing to keep the boat for 10 years, will the motor make it....25 years?....probably not. Look for a great boat with running motor that you can discount so much it won't hurt if you have to repower.
Then get a shiny new F250 or DF250 and enjoy 10 years worry free.

If you don't plan on 10 years but maybe 2 or 3, then go with an old F225. You'll save a lot of gas & oil and lung capacity.

 

[Ky Grady]

I'm in the '04 F225 group. When I purchased my boat, I knew going in I was going to have to have the exhaust done. G8RDave and I discussed this and a price was agreed upon reflecting the estimate I had received from my Yamaha mechanic for the repairs. Me, personally, prefer the 4 stroke over the 2 stroke for the things mentioned above. The 66 is the old school workhorse motor, hard to kill if it's been maintained. The F225 will need the exhaust done, not aware of any other major issues. General maintenance is needed for any used motor you buy along with being checked out. Mine was purchased with 1180 hours of full saltwater use it's whole life, I'm at 1260 now and you can't even hear it running. I did go fully through it and replace all maintenance items and full 1000 hour service when I bought it to have a baseline from which to use for service intervals now. That being said, it could blow next time out. I hope it doesn't and I can get a few more seasons out of it till I can swing a repower and go to the 4.2 F250.

The boat you're looking at with the F225, has the exhaust been done? If not, use that for negotiation purposes. When was the last time it was serviced? Have receipts for said service?

Between the two motors, the F225 gets my vote.

 

[Gianni]

You should have any used outboard checked out by a mechanic before you put down cash. Or you can do it yourself if you're handy.

While the OX66 is reliable, they do eventually blow up as the result of age and lack of use. It's internal corrosion that can cause a bearing to spin or a wrist pin to let go rather than the parts wearing out. I've also seen them fail as the result of fuel system issues. If fuel is restricted or one of the carbs gunks up, a cylinder will run lean and overheat. But if they are well maintained and run frequently using good fuel they can last for 20 years or so.

There is really nothing wrong with the F225 except for the dry exhaust corrosion issue. Engines made after late 2007 do not seem to have the problem. In any case, it's not difficult to detect before it gets to the oil pan where catastrophic engine failure can occur. You just remove the lower unit and look up inside the exhaust tube with a lighted borescope. If you see pits forming, you have the problem. Salt crystals in engines used in saltwater are to be expected and are not an issue. There are lots of pictures of exhaust corrosion available online.

Personally, I would never go back to a 2-stroke engine. I've been a 4-stroke guy since 1998. I hate the noise and stink of a 2-stroke when I'm on a friends boat. Plus, you realize at least a 30% increase in fuel economy vs a non-direct injected 2-stroke.

Please explain the “blowing up” you mentioned. I have those motors and wouldn’t like a surprise like that. Thank you

 

[Gianni]

I have 1999 ox66..

I’ve done my best to maintain them- last few years they’ve been giving me problems. Was water in fuel a problem- yes but there have been other issues. They do smoke a lot- but if they run good- they are a nice motor. I’m Personally either giving it one more shot this year investing money into them or im going to have to go another route

 

[Heyspike]

I'm in the '04 F225 group. When I purchased my boat, I knew going in I was going to have to have the exhaust done. G8RDave and I discussed this and a price was agreed upon reflecting the estimate I had received from my Yamaha mechanic for the repairs. Me, personally, prefer the 4 stroke over the 2 stroke for the things mentioned above. The 66 is the old school workhorse motor, hard to kill if it's been maintained. The F225 will need the exhaust done, not aware of any other major issues. General maintenance is needed for any used motor you buy along with being checked out. Mine was purchased with 1180 hours of full saltwater use it's whole life, I'm at 1260 now and you can't even hear it running. I did go fully through it and replace all maintenance items and full 1000 hour service when I bought it to have a baseline from which to use for service intervals now. That being said, it could blow next time out. I hope it doesn't and I can get a few more seasons out of it till I can swing a repower and go to the 4.2 F250.

The boat you're looking at with the F225, has the exhaust been done? If not, use that for negotiation purposes. When was the last time it was serviced? Have receipts for said service?

Between the two motors, the F225 gets my vote.

Ky,
What kind of money are we talking for the exhaust being done? One of the boats at a marina said it was checked out and ok, one f the other boats I was looking at said it was replaced.
Is it something a handy man can do or just a mechanic?
Thanks,
John
*
I you tube it, big job. Lots of info out there. I guess the exhaust manifold gets replaced.

 

[Ky Grady]

Mine ran me a little over $2100, parts and labor in August of '17 for exhaust only, total bill was $2890, which had new motor mount bolts, new timing belt, new plugs and a few more miscellaneous pieces that needed replacing due to corrosion.

I could have done the work myself and saved me the labor, but not being a Yamaha dealer or having one close, I felt better letting my guys in South Carolina do the work since they had access to any parts they would need.

If you're handy and have a general knowledge of what you're doing and have a hoist available, powerhead has to come off, then yes, you could do it yourself.

If one of the boats you're looking at says exhaust has been done, I would want to see the receipt. Even if it was done by the current owner, he will have a receipt for parts. The one that says it's been checked and ok, I would ask to have my mechanic verify that it is ok, then proceed. The marina is getting a percentage to broker the boat for the owner, unless you trust them, I would have it verified by my trusted mechanic.

 

[Doc Stressor]

Please explain the “blowing up” you mentioned. I have those motors and wouldn’t like a surprise like that. Thank you

Blow up is just a general term for a mechanical failure.

I've had two 2-strokes blow up on boats that I've owned over the years and I was able to get back in both times. One was a wrist pin failure that tore up the cylinder wall and beat up the top of the head. Amazingly, the piston held together and I was able to run over 10 miles at low speed. The second had a spun bearing with the same lucky outcome. When a major mechanical part fails, the engine sounds like it is ready to blow up. But back in the days before SeaTow, I figured I'd just limp in as far as I could and call the Coast Guard if we couldn't make it.

A friend that I trade offshore trips for inshore trips in his bay boat had a pair of OX66's fail over the past few years. The first failure was a wrist pin and a partially melted piston on a 2007 150 hp. He was able to make it back in from not too far away. But he had to use his trolling motor for the final mile or so up the river after the engine quit. He replaced it with a 1999 175 hp with low hours. That one threw a connecting rod right through the engine block. That required a tow. We took that one apart but don't have a clue why it failed. The rest of the internal parts looked fine.

The point is that everything has a finite lifespan. The term Bullet Proof just means that the OX66 has a longer mean time before failure than most other motors. One thing that you can do with older OX66s is to block the oil injection system and pre-mix your oil and fuel. That eliminates lubrication failures that might result from the oil injection system.

 

[Fishtales]

They are both solid motors. The mid section corrosion issue is a known issue and can be corrected for about $3500 an engine (there are some other recommended things to do in that price while in there). If you are worried about the F225 have it scoped. They should be able to tell you if there are issues or not. Some of this was water temp dependent. The Yamaha heat map (locations where motors failed) was heavily biased toward warm water in addition to salt, exhaust gasses and heat. I wouldn't rule either out on input from the board.

 

[Heyspike]

Mine ran me a little over $2100, parts and labor in August of '17 for exhaust only, total bill was $2890, which had new motor mount bolts, new timing belt, new plugs and a few more miscellaneous pieces that needed replacing due to corrosion.

I could have done the work myself and saved me the labor, but not being a Yamaha dealer or having one close, I felt better letting my guys in South Carolina do the work since they had access to any parts they would need.

If you're handy and have a general knowledge of what you're doing and have a hoist available, powerhead has to come off, then yes, you could do it yourself.

If one of the boats you're looking at says exhaust has been done, I would want to see the receipt. Even if it was done by the current owner, he will have a receipt for parts. The one that says it's been checked and ok, I would ask to have my mechanic verify that it is ok, then proceed. The marina is getting a percentage to broker the boat for the owner, unless you trust them, I would have it verified by my trusted mechanic.

Thanks Ky, never thought about the receipt. It would be the biggest job I would have done to date, I don't mind wrenching on things, but the idea of going from an 88' Mercury 2 stroke to something I might have to do major work too IS exactly what I was trying to avoid. Maybe I can use it to lower the cost of the boat then just go ahead and do the job before spring. Or save a bit more and try to get an 07'.

 

[Doc Stressor]

There is a thread on THT right now where a guy shows a pictorial of how to do the exhaust tube replacement on an F225.

F225 Dry Exhaust Replacement

 

[hinmo]

You should have any used outboard checked out by a mechanic before you put down cash. Or you can do it yourself if you're handy.

While the OX66 is reliable, they do eventually blow up as the result of age and lack of use. It's internal corrosion that can cause a bearing to spin or a wrist pin to let go rather than the parts wearing out. I've also seen them fail as the result of fuel system issues. If fuel is restricted or one of the carbs gunks up,.

Carbs? OX66's are fuel injected I believe.

 

[Doc Stressor]

Carbs? OX66's are fuel injected I believe.

Yeah, you're right. I was confusing the carbed Saltwater Series with the fuel injected OX66. Both were available at the same time and had similar reliability characteristics. The O2 sensor on the EFI engines had some issues, but they weren't the kind of problems that could leave you stranded.