Broken timing chain on a 1.8L yamaha engine. Are these freewheeling or not?

[Ronnie]

Trying to determine if the valves are damaged as well.

 

[zipper]

The MR-1 HO’s are interference engines. Not sure about the 1.8’s.

 

[dgfreeze]

I was under the impression they are interference engines, which is why it's such a catastrophic issue when they let loose. I haven't done any research on it, so I'm hoping I'm wrong, for your sake...

Hopefully someone with real knowledge on the matter chimes in...

 

[Cobra Jet Steering LLC]

if you hatched a chain you probably did a job on the valves 4 per cylinder

 

[Neutron]

Yes its an interference motor, some valves are going to be bent

 

[Ronnie]

Thanks guys that is what I suspected but was hoping to be wrong. I had a mobile mechanic come over today.

we ran a compression check that came back at 0, 120, 0 and 0 on cylinders 1, 2, 3 and 4, respectively. All bad at that point. Decided to do a leak down test but canned that idea when the valve cover removal revealed a broken timing chain.

he said this a great news and explains why so many cylinders came back at 0 psi (the valves on those cylinders were open). The caveat being that he didn’t know if the engine was freewheeling/interference or not. If not valve damage likely occurred when the timing chain broke.

the boat gave me 10 years of great memories with few problems and the failure happened at the end of the season so I won’t complain. I will call a local shop I trust soon to discuss when i should bring it in and how much it will cost. With 4 valves per cylinder and 4 cylinders I have a bad feeling about that conversation but the valves need to be removed before an accurate quote can be developed soon I will request a worst case scenario quote.

On a related note, I will be giving my 30 day notice of intent to cancel my slip rental tomorrow. I will get half of my deposit back and really won’t need the slip again until the boat is repaired. If time permits I will try to order a new windshield as well.

 

[Ronnie]

I forgot to mention that we could not spin the crank with the spark plugs removed by hand via the shaft or with the broken chain on the gears, so we couldn’t get the other vale was to open or any cylinders to top dead center (tdc). At that point o pretty much new I had valve problems but at least the bottom half of the engine and cylinders should be ok. Half empty or half full? It all depends on your perspective. If the quote comes back at $3k I’m going to try and remind myself it’s better that $6k or even $3,001.

 

[Ronnie]

I may reach out to SBT as well regarding their engine swap/repair services but suspect shipping will be prohibitively expensive such that the cost to repair locally will be better.

 

[I_squared_r]

I'm curious how many hours that you have? My 2014 is at 280 hours and the chain is holding up. Fingers crossed.

It's a interference engine and always causes carnage when the chain lets go. The next move is to remove the cylinder head and see if the pistons have any serious damage. The best scenario is that the pistons are fine. Then you can replace the cylinder head, change the cam gears to 2016+, install 2016+ timing chain guides, and 2016+ timing chain. I've heard that people are using the existing crankshaft with the wider chain.

 

[jmargo]

As others have mentioned it is almost guaranteed there was piston to valve contact. Depends on the extent of it some damage is not bad enough to replace pistons. If you have access to a borescope or one of those small inspection camera's you can give it a look and that can help with your game plan.
Had you ever inspected the chain ? I started doing it as part of my preseason service.

 

[Neutron]

When these engines bend valves its, a very slight bend in the stem, sometimes its so slight you can barely see it opened, so it doesn't do damage to the piston. If any its just a slight mark.
Realistically it just needs, new chain, valves(the bent ones, usually not all valves, head gasket kit with valve seals, spark plugs. The rest is labor. Can be done in boat but some pull the engine to make it easier

 

[Ronnie]

Thanks for the positive and informative posts guys but based on what I’ve read so far it looks like I’m F’d. I will bring it to a shop asap and have them give me a quote before deciding what to do. I’m going to get it fixed but don’t yet know if it will be an engine repair or replacement (with a used engine). I know I am not considering a new engine anyway.

while the boat is down this off-season I plan to replace the the upholstery and broken divers side window if I can find one, tint the exterior of all windows with silver tint and generally clean up and dwatial the boat. It will be my offseason boat project.

 

[Ronnie]

To add insult to injury to found this hanging on my front door today, after the boat mechanic left.

 

[bjlkemper]

Man that notice sucks worse than the engine in my mind! Sorry about the bad news all the way around man!

 

[I_squared_r]

Thanks for the positive and informative posts guys but based on what I’ve read so far it looks like I’m F’d. I will bring it to a shop asap and have them give me a quote before deciding what to do. I’m going to get it fixed but don’t yet know if it will be an engine repair or replacement (with a used engine). I know I am not considering a new engine anyway.

while the boat is down this off-season I plan to replace the the upholstery and broken divers side window if I can find one, tint the exterior of all windows with silver tint and generally clean up and dwatial the boat. It will be my offseason boat project.

My guess is that the mechanic will charge labor to remove the cylinder head, confirm what you already know, and then provide a quote for a SBT engine and/or used engine. In my experience it's rare for a mechanic who does internal engine repair. Personally, I would remove the cylinder head before considering my options. It's possible that you can save a serious amount of money by doing this, source the parts, and find someone to repair your engine. But I understand that not everyone has the experience or tools to do this (I was an auto mechanic a long time ago). I would help you if we lived closer.

Sorry about the ticket. This irks me because I believe in the freedom to do with your property as you please. You pay for the property and others should mind their own business ?‍ Maybe you can speak with them and get this reduced or dropped.

 

[Cobra Jet Steering LLC]

I doubt that, I would bet a neighbor complained. That is usually how that stuff happens

 

[HangOutdoors]

Yep, that is how I get notices. Somebody complains.

 

[Ronnie]

Nothing like a kick in the teeth to finish off a bad a$$ week. I’m trying to remain positive, make lemonade when life gives me lemons but what am I supposed to do when life gives me $hit like this Make $hit pies? Anyone in the market for some fresh $hit pies? Hell I will pay for someone to take them and deliver them for free personally and immediately.

i say this as I look out my home office window at boats in the driveways of my nearby neighbors that have been there for weeks, months, possibly years. Now I don’t know who to trust. Racial/ discriminatory enforcement? Maybe , maybe not but since all my neighbors with boats in their yards seem to be Caucasian and didn’t get notices like I (a non Caucasian) did, it feels like selective enforcement to me. Crappy argument I know, like asking why I am the only one who got a speeding Ticket when everyone around me was going the same speed.

makes me wonder if Karma is real or imagined, probably really imagined.

 

[HangOutdoors]

@Ronnie Seems awful odd that your Caucasian neighbors aren't getting enforcement notices for the same thing........ When it looks like a duck, quacks like a duck and walks like a duck....... Behaviour like this and possible discrimination infuriates me. I would leave your shit there, take pictures of everyone elses with date time stamps on the pictures and roll into court when they try to enforce or fine. Stir it up.

 

[I_squared_r]

Nothing like a kick in the teeth to finish off a bad a$$ week. I’m trying to remain positive, make lemonade when life gives me lemons but what am I supposed to do when life gives me $hit like this Make $hit pies? Anyone in the market for some fresh $hit pies? Hell I will pay for someone to take them and deliver them for free personally and immediately.

i say this as I look out my home office window at boats in the driveways of my nearby neighbors that have been there for weeks, months, possibly years. Now I don’t know who to trust. Racial/ discriminatory enforcement? Maybe , maybe not but since all my neighbors with boats in their yards seem to be Caucasian and didn’t get notices like I (a non Caucasian) did, it feels like selective enforcement to me. Crappy argument I know, like asking why I am the only one who got a speeding Ticket when everyone around me was going the same speed.

makes me wonder if Karma is real or imagined, probably really imagined.

Do you have any bad neighbors? We had 1 many years ago. He was friendly until my parents put up a 6ft fence for privacy and he felt that the fence blocked his view from pulling out of his driveway. He called the town on them for everything. My parents ended up moving the fence back about 25ft, lost a good part of their yard, and still the guy was a asshole until he died.