Yamaha f225 knocking sound

[sneakybender24]

Hi,
Picked up a great '90 offshore 240 about 4 months ago, with 1100 hours on the 4 stroke yamaha on the back. It's run like a champ since I bought it for about 50 hours. On my way to a fishing spot this afternoon, at 4400 rpm, it started sounding funny and is making a bad knocking sound in and out of gear at all rpms. It follows engine speed. I changed the oil shortly before going away for the holidays and ran it around for a couple hours about a month ago. It fired right up this afternoon. The seller said it was scoped for exhaust corrosion but that's just what he said.

I shut the motor off and am getting towed back in to prevent more damage.

Here is a video:

Yamaha f225 knocking sound

youtube.com

Thanks!!

 

[SkunkBoat]

Check the plastic cover on the flywheel. I changed oil and later heard a tick. i must have leaned on the flywheel cover and it was just barely ticking. Loosened up a screw and it is fine.

edit: OH! just watched the video. No, thats not good. I don't think its plastic

 

[loubeer]

If the motor has not had the corrosion repair kit installed, I'm not optimistic about what you're going to find. I hope I'm wrong.

 

[wrxhoon]

It doesn't sound good, sounds like big end bearings . I hope I'm wrong.

 

[FirstTimeGrady]

I dropped my lower unit, and this sound went away. Give it a try, you may get lucky.

New video by Jim Arndt

photos.app.goo.gl

 

[sneakybender24]

Thanks for the help. I pulled the cover off the top and it's definitely not rubbing on the plastic, but I have read a few threads about it being the lower unit. Unfortunately submerged logs are an issue around here so I may have hit something although there aren't many signs of it. We'll see what happens tomorrow when I get to it.

 

[seasick]

Pull spark plug wires, one at a time and restart. You want to see if the noise is noticeably less when a specific cylinder is disabled. If it is, there may be a bad con rod bearing, wrist pin or piston slap. I can't tell from the video; does the motor have a significant knoch feel if you hold onto the motor. If not, the noise may be exhaust leak.
If the knock and/or shaking is the same with the motor in neutral and in gear, I wouldn't lean towards a bad lower unit.
Also check the oil for too little, too much or foamy or cloudy.

 

[Mustang65fbk]

Has the motor had the dry exhaust corrosion issue taken care of or at least scoped for? The previous owner of my boat had the dry exhaust corrosion issue on his motor and didn't realize it, went out to start it up and it was shooting water out of the cowling. Long story short, I guess it ended up having a hole in the block and they had to replace the entire motor. When you changed the oil did you make sure you put the new oil in after draining the old oil out? My old man did that once on one of his cars where he drained the oil and then started it up with no oil in it for about 30 seconds or so before realizing he hadn't added the new oil back to the motor. Besides that you can always check your spark plugs as well as your fuel to see if there's any water in it or if it needs some sort of fuel stabilizer.

 

[sneakybender24]

Some goods and some bads with the lower unit off. The noise is gone, but it looks like the exhaust is pretty corroded.
I checked the oil, and ran it for an afternoon after changing the oil (added a nmea fuel flow sensor so I needed to test that). It had no codes on the computer. After a little more research there's a bunch of threads on THT about a bushing in the lower unit where the driveshaft comes in that does go bad and make that noise. Seems like a $35 fix for the knock.

Does anyone have experience doing the exhaust corrosion fix? Is it worth doing myself or just taking to the yamaha shop?

Yamaha f225 no lower unit running

youtube.com

 

[Mustang65fbk]

That looks pretty advanced in terms of the corrosion problem. I'm assuming you pulled the lower unit yourself and looked up there and that's what you saw? Was there any other signs of corrosion elsewhere throughout there motor? If you're at all mechanical, which it sounds like you are, then there's a video, well I'm sure multiple videos, that I saw on YouTube that goes through the entire step by step process. I'd start calling around now though as the last I heard the repair kits were on backorder because they couldn't get all of the parts sourced for them. I think the kit itself is just over $600, and then if you do it yourself you just have your labor into doing the repairs. I looked at several GW 228 Seafarers before I ended up buying mine and most of them had F225 Yamaha's with the dry exhaust corrosion issue and most places started at around $2k to do the fix. Which includes both the parts as well as the labor for doing the work on the motor and I figured if I did have that issue then $2k is a relatively inexpensive fix. And it beats having to buy a whole brand new motor. But, the local GW dealer here that I talked to on the phone also mentioned that oftentimes you'll have the dry exhaust corrosion problem and then it will spread to other parts that it touches with the corrosion issues as well, which could result in having to replace a powerhead at around $5k-6k, or worse would be having to replace the motor altogether. My motor has just under 1k hours on it, of which it was inspected for the dry exhaust corrosion issue and luckily it doesn't have it, at least yet. Some say it starts around the 500-600 hour mark, which is right where it happened for the previous owner of my boat when he got a hole through his block. They say that the earlier on you catch it is the best because it typically means the least amount of money you'll spend with repairs and typically won't need a new powerhead or a new motor altogether. Good luck with the repairs, hopefully you just need the $2k fix for the dry exhaust corrosion issue and not a new powerhead or worse.

 

[Mustang65fbk]

Also... it depends on what year of Yahama you've got but here are a couple of links to exhaust kits. Not sure of the availability but it gives you a ballpark figure for pricing. Hopefully you've got the 2004 and newer model and it looks to be readily available compared to the 2002-2003 which appears to be on backorder for 6+ months or more.

https://www.boats.net/product/yamaha/MAR-EXHKT-03-00?gclid=EAIaIQobChMIgbrqtNG09QIVVh-tBh0lyAcQEAQYASABEgJjmfD_BwE

https://www.boats.net/product/yamaha/MAR-EXHKT-04-00?gclid=EAIaIQobChMIgbrqtNG09QIVVh-tBh0lyAcQEAQYAyABEgL0KfD_BwE

 

[sneakybender24]

@mustang Thanks! After looking at the video pulling the powerhead off is probably more than I have space/tools/time do deal with right now, so off to the dealer I go. I haven't seen many other signs of corrosion around the motor while doing other jobs but that doesn't mean there isn't any. It's a 2002, so it looks like I may be waiting a bit to get the parts. I may have them scope it to see how bad the corrosion is then just run it so I don't miss salmon season!

 

[Mustang65fbk]

@mustang Thanks! After looking at the video pulling the powerhead off is probably more than I have space/tools/time do deal with right now, so off to the dealer I go. I haven't seen many other signs of corrosion around the motor while doing other jobs but that doesn't mean there isn't any. It's a 2002, so it looks like I may be waiting a bit to get the parts. I may have them scope it to see how bad the corrosion is then just run it so I don't miss salmon season!

I'm assuming the years aren't interchangeable but it might be worth a phone call to double check on that. I'd also maybe make a few phone calls and check with Yamaha or other dealers/vendors to see what their status is with the parts kit. I checked 5-6 other sites and most say that it's backordered, except for one, which doesn't say what the availability is. Although, if it's backordered from multiple dealers/vendors, I'm assuming it must be backordered completely and likely that nobody has one. Your local Grady White dealer or whoever works on your outboard would likely be able to give you a much more definitive answer than I can. I too watched the video and figured I'd rather have a dealer or someone who knows what they're doing to do the work for me, as I'm sure that I could do it and do it successfully, but I'd rather have the peace of mind of someone who has done it hundreds of times before do it instead of myself.

Yamaha Outboard Exhaust Kit - Fits 2002-2003 F200 & F225 3.3L V6 - MAR-EXHKT-03-00 | PartsVu

PartsVu

www.partsvu.com

 

[sneakybender24]

I'm hoping the local Yamaha guy can help with some of those questions, and maybe has a kit lying around. Partsvu is also likely backordered too, they just don't say it on their site. I've had them do something like that in the past and not tell me it'd actually be a couple months before I get my parts, as a heads up. Also, I'm in the Skagit area, do you happen to know of any places that might sell used parts around? I may reach out to them as well.

 

[Mustang65fbk]

I'm hoping the local Yamaha guy can help with some of those questions, and maybe has a kit lying around. Partsvu is also likely backordered too, they just don't say it on their site. I've had them do something like that in the past and not tell me it'd actually be a couple months before I get my parts, as a heads up. Also, I'm in the Skagit area, do you happen to know of any places that might sell used parts around? I may reach out to them as well.

Yeah I'd assume they're backordered as well since just about everyone else seems to be. Skagit as in Skagit County in Washington state? If so, hello neighbor haha! I'm near Everett in Snohomish County but would call Jacobsen's Marine in Edmonds as they're the local GW dealer for I believe the entire PNW. Also, Bayside Marine is probably worth a phone call as I believe they're also a Yamaha dealer/repair shop and I think there's a marine shop in Marysville that also works on Yamaha's. I just bought my boat in early October, used it a couple of times and then had it winterized for the season by Jacobsen's. They're pretty honest and fair in terms of pricing, I think it's definitely worth a phone call to them and tell them what you've got. They're the ones who quoted me at $2k to fix the dry exhaust corrosion issue if I had the issue with my motor. Although, fortunately I don't at this time. When I was in there getting my boat winterized, they had another boat that was getting the dry exhaust corrosion issue being worked on as well. They said that they've done it many, many times before.

 

[seasick]

You mentioned that you tested with the lu off the noise is gone. Did you run the motor without the lu attached?

The bushing you mentioned is not all that easy to replace either and also when it is bad, the motor tends to squeal not knock.

 

[sneakybender24]

I ran it with the lower unit off, and I'm about 95% sure that the sound went away, but it's a little tricky with the exhaust being much louder. Either way, since I saw so much exhaust corrosion, I'll be taking her to the shop this week.

 

[seasick]

I am not so sure I would run that motor without the LU attached depending on how you cooled it.

 

[moklodge]

If your guy is a Yamaha tech, he'll know to check the thermostat bore as well. With the age of that motor, the corrosion may have well reached the base of the powerhead and the therm bore. The flange on the exhaust tube is completely gone.

 

[brdawg2001]

Kinda interesting...I have a 2002 273 Chase with F225's and owned since new.....never had the corrosion issue...one of the motors threw a rod in 2018 with 1800 hours running 4000 rpm offshore..hole in the side of the block..

Repowered with Zuke and did not look back.

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