How much corrosion expected in 2005 Yamaha 225hp with 650hrs?

[meletong]

I know there is a known issue with this motor. Dropped the lowers during a survey and found some corrosion. Should you see any corrosion on 16 year motor in the exhaust? Thanks in advance!

 

[Ted R]

Was it a salt water motor of fresh water? My 2004 225 has been in fresh water since new and no issues.

 

[Doc Stressor]

This is a picture of what I would call "normal" corrosion in a 200-250 hp Yamaha midsection. No deep pitting. The spots look like salt deposites.

 

[Uncle Joe]

If it is a saltwater motor you should flush it periodically with fresh water. There is a hose connection just below the head for this purpose.

 

[Legend]

I had 04 225 with 750 hours and they were flawless. Had them scoped every time we did water pumps. 2017 They had corrosion and it got into the power heads. Expect the worst and have them scoped. I had to replace with two new engines. Expensive repair but a lot cheaper than a repower. They are great engines aside from this issue.

 

[Doc Stressor]

If the midsection looks like this one, it should be replaced. Notice the pitting. This is a dry part of the exhaust system so flushing does nothing to prevent the problem. It only seems to occur on engines used in saltwater.

 

[meletong]

Was it a salt water motor of fresh water? My 2004 225 has been in fresh water since new and no issues.

Saltwater

 

[meletong]

If the midsection looks like this one, it should be replaced. Notice the pitting. This is a dry part of the exhaust system so flushing does nothing to prevent the problem. It only seems to occur on engines used in saltwater.

View attachment 21411

It was not as bad as that … more like this …

 

[Doc Stressor]

I see pitting. It should be replaced.

 

[loubeer]

My 225's lasted 1900 hours and 18 years. Your hours are much lower, but the time is about the same. Salt corrosion is relentless and plays no favorites!!!

 

[Doc Stressor]

It has a lot more to do with age rather than hours. I saw a 2005 with only 300 or so hours that was pretty rotted.

They had an alloy problem with certain sourced midsections. Not all engines were affected. They never came straight about the issue so nobody really knows what is going on. The problem mostly went away after the 2007 model years.

 

[loubeer]

I totally agree with Doc Stressor. Like I said, mine lasted 1800 hours and I used the "Repair Kits" offered by Yamaha to replace corroded parts about 5 years ago. They were pretty reasonable, but labor costs certainly added to the bill. With your low hours, might be worth looking into. However, as Doc Stressor mentioned, age may bite you in another totally unrelated section of the motor. That's what happened to me.

 

[Jamato14]

I had a 2002 F225 on my last boat. Bought it with some corrosion, ran it for a year no issues then did the exhaust update. Mine came apart easy and had not gotten to the block. There’s no true signs of of it gets to the block without pulling the block. Scoping only goes so far (discussed with numerous certified mechanics). I got mine replaced for $3500ish with a few other small things. Motors are great I put almost 200 hours in the year and a half I had it (bought with ~640 sold with ~830 if memory serves me). This was within the past few years (just sold in March). Boat ran even better once exhaust was replaced and I was expecting it to go another 1000 hours or so if I kept that boat. Salt/fresh water and flushing have nothing to do with this corrosion issue based on my research and understanding of the motor. Yamaha first gen 4 strokes in the 200-250 range used dissimilar metals in the dry exhaust (section it corrodes in), therefore the environment and flushing make no difference. The dissimilar metals reacted to eat away at each other. Yes flushing is the proper procedure but the different metals made it irrelevant for this piece of the engine.

Did it come back with a lot of overheat alarms from the readout? That can be one sign with the block being impacted. If not just get quotes and plan on the exhaust update within a year and it will be a good engine and likes to run. Mine ran better the day I sold it than the day I bought it because I used it twice as much as the last owner and it liked running

 

[mmiela]

Get it done mine looked like yours and if I had waited it would have been a power head not just the exhaust. It stinks that Yamaha didn’t admit fault and screwed a lot of owners.

 

[Evopro54]

I'd be wary of the thermostat housing rotting issue as well. They notoriously fail within a few inches of the thermostat leaving a 1/2" sized hole at the top of the block. Lost my '
'06 225 to water ingestion when it failed last year.

 

[max366]

Like evopro, my port '04 F225 had severe corrosion at the thermostat and the resultant hole sprayed seawater into the air intake. I needed a new powerhead. $15K

In '06 F225 Yamahas and later, they added an anode to the thermostat housing, which I retrofitted to my starboard engine (the new powerhead had the anode). I remove the thermostats every year to monitor the corrosion and with the addition of the anode, the corrosion seems to have stopped. You might consider changing the housing to the newer design.

 

[brdawg2001]

This is always interesting..I had a 2002 and it lasted 18 years and 1800 hours with no corrosion issues...threw a rod so I replaced them.....I always flush with engine up as the manual states...never used saltx, which I do now..