2005 DF140 lost compression all cylinders in the slip

[BlueOcean]

At the end of last season the engine was running fine. Last trip out in December it was cold below freezing outside, on startup in the slip engine made a noise as if the starter was possibly sticking after start up that would go away after a few seconds, so I shut it down and sprayed the starter with WD-40. I started it up again same noise, shut it down and tried to start it again and the third time and would not start. Tested for spark and gas in the slip and had both. After pulling my hair out confused a few days later called SeaTow, flushed the engine and sprayed fogging oil in all cylinders turned it over a few times and it sat for a month or two before I started messing with it. Here is what I found.

All cylinders lost compression, all around 40psi. I took the power head off thinking the timing chain was off which maybe it is. I have the factory service manual and it seemed to take almost 10 revolutions of the timing chain itself to get the dots on the sprokets to line up with the blue links and **** link on the chain. They will line up it just takes a lot of full revolutions to get it to do it on all other revolutions nothing is lining up correctly. While turning the crank by hand the timing chain goes slack for a minute then gets tight as if something is wrong with the chain but I do not observe it jumping a tooth.

Leakdown test had 80% leak for all cylinders except 4 which was marginally better at 70% with audible air coming out of the exhaust during all tests for all cylinders.

I'm a bit stumped at what to do next. I know the heads need to come off and the valves rebuilt, but what was the cause for loosing compression in all cylinders at start up? I would hate to bring the heads to the machine shop for rebuilding install it and have the same thing happen because the timing chain or something in the valve timing is off. I don't know what a normal chain should look like for a DF140 but it seems odd that it takes me turning the engine by hand multiple times to get everything to line up like in the manual, and even when I do get the dots on the crank sprockets and the cam sprockets with the correct links in the chain the driven gear mark never lined up correctly. Does it usually take a lot of revolutions to get the timing chain to match up correctly with the marks on the gears? The engine is 16 years old although the internals look clean the chain may be stretched?

Any ideas about this I would love to hear, thank you in advance.

[Handsomerob1980]

(Not a marine mechanic) however, when the timing is initially setup you set the timing per the marks however it may take many revolutions for the marks to ever line up again. When doing the leakdown tests you need to have each cylinder at top dead center on the compression stroke and have the crank locked into position so it won't rotate once you add the air. not sure if this was done just checking. If you have leak down then it sounds like the tensioner has failed and the chain skipped. I would suggest resetting the timing doing the leakdown test again and see if it holds pressure. If it does get a new timing chain set with tensioner and install. If not well maybe valve damage occurred and the head needs to come off and valves inspected.

I'm sure there are other Suzuki techs out there that can chime in, but this is where I would start.

[Murray]

Don’t know if this applies to you but I’ll tell you my story. Owned a 4 stroke Yamaha dirt bike decades ago, after sitting for the winter that SOB would not start. I’d be jumping on that kick start for hours no luck. A neighbour came over, pulled the plug and dumped about a tablespoon of oil in the plug hole, he had me turn the engine over a few time with the plug out. 8-10 kicks it started. His explanation was the piston rings have dried out, therefore you don’t have enough compression to start the engine.

[Handsomerob1980]

So this is the timing chain parts break down from Suzuki, so best case scenario is that the tensioner has failed and the chain skipped a tooth or two and the valves are now out of time. Worst case the pistons came in contact with the valves and bent them etc. I would suggest retiming the engine as I said before and checking to see if you have no leak down. If it's good then new timing chain kit with guides and tensioner and you're back in business.

DF140 timing.jpg

[BlueOcean]

Thank you for the help! Much appreciated. I took your advice about redoing the leakdown test. I actually took the cams and timing chain off completely so that I knew every valve was closed and repeated the leakdown tests. Air was still coming out of the exhaust but instead of being at 80% leak they were at 60%, all cylinders showed improvement but still leaky. I took the heads off and went to my local cylinder head machine shop that specializes in rebuilding cylinder heads. As soon as he saw the head he said I blew my head gasket and pointed to the area where there was some faint black between two cylinders. This would explain a few things, but i'm not sure if I had contributing issues, the onset of the issue is odd I woudn't think the head gasket could go while at idle but perhaps it went on the cold engine i'm not sure. Either way I left the head there for his inspection to see if he thinks it needs to be rebuild or any of the valves are off which I assume at least the exhaust valves will fail. Otherwise the tops of the pistons look caked in carbon but decent and the cylinder walls still display slight cross hatched markings which is good. I will still definitely replace the timing chain and possibly the tensioner to rule those out before reassembly. But I WAS able to get all marks lined up with the proper linkages on the chain before disassembly, I don't know if that definitely says the timing was not off, that question is a bit over my head but losing compression in all cylinders is odd for it not to be related to the timing chain but I guess crazier things have happened. I will keep up with how this turns out in case any one in the future has a similar issue.

[Handsomerob1980]

It would be a very unique situation to have lost compression on all cylinders from a head gasket issue. Commonly it would be 1 cylinder into the cooling passage, or into the adjacent cylinder. All cylinders would be a timing issue especially if it's passing through the exhaust valves. It could be however a cracked or warped cylinder head. I'm just hypothesising as without physically seeing the engine it's all here say.

DF140 headgasket.jpg

[briscoe]

You know, at this point, it may be worth just considering buying a rebuilt power head. I know the DF140 is very popular and there are many places that you can get one. It might save a lot of brain trauma. Just a thought. I've seen them for 3850. It may sound like a lot, but I imagine their margin is small. Suzuki parts, yikes, are expensive. Think about what it takes to go through the entire top of the unit. Or it may be time to just repower, which is 15K plus

[D'oh999]

The engine has to get it's air from somewhere. So if the Intake is plugged, no air going in means all cylinders just become a vacuum tube. Mouse/Bees Nest in the Air Box would be suspect if it was running fine last fall on storage.

Sorry, didn't realize you have it apart already.

[BlueOcean]

Thanks for the feedback. Yes engine is apart, I brought it to the cylinder head shop. They said I blew the head gasket and the exhaust valves were overheated from blocked passages causing them to fail. On further inspection I found sand in some parts almost completely blocking the water passages. Its odd how one day it was working, but for all I know the day before I was barely getting by at just barely enough compression then the morning I tried to start it she finally said enough is enough.

I will say I am very gently on my engines. I often put the throttle at 4K and just purr out to the fishing grounds, lots of idle - 2k maneuvering then 4k back. I should have been WOT every now and then to force water through the engine at a high rate. I also did not flush the engine after use because I do not have a hose at my dock although I will get one now after this is all said and done.

They are rebuilding the head, they said the casting is fine, new exhaust valves, springs and intake valves, new gaskets going in. I'm currently cleaning out the passages and trying to clean all caked on carbon from the block. I thought about just going for a new powerhead, but everything else looks pretty rock solid and lucky to have a machine shop/cylinder head spe******t up the street from me that i have done work with before so I trust them. If I didn't have the shop to help me I probably would have went new engine or new power head to be honest.

[tsturm]

I had a over rev (cavitation) issue once that knocked some of that carbon loose and pieces/chunks got stuck between valves & seats causing a similar loss of compression.
Now about every 200 hrs. or so I de-carbon the combustion area with seafoam. As in running at 1500 rpm dump a can in the air intake(air box removed) until it stalls then let it soak for a hour or so. Hell to get started back up but you should see the shit that is blown out!! Any way good luck with your head rebuild.

[BlueOcean]

Tsturm lots of carbon everywhere when I pulled the head, lots! That is a possible cause. I use Startron with every fill up I add some to the tank, but this engine is new to me as of two years ago so who knows what the first years of it's life were like.