MrGiggles

Charging issue was just a bad fusible link. Working well now. The power trim issue has something to do with the trim limit module. It can be taken off since there is nothing for the cowl to crush on my rig if it's trimmed too high. I did a proper compression test and came up with 175psi on #4. The rest are closer to 190, but it isn't broken in yet.

Walmart 29DCs are my go-tos until lithium comes down a little. Although in a canoe I would certainly give lithiums a look for weight if nothing else.

I thought the same thing, but there was no corresponding damage to the head. I'm certain preignition/detonation was the cause, but the cause of that is what I'm not sure of. A heavy shot of ethanol will do it for sure, especially since these don't have an 02 sensor or any way to monitor A/F ratios. A car would've run like crap, pegged the fuel trims and set a lean code, but would be undamaged. One thing that did cross my mind is if it could be related to the FSM issues on these. Any sort of problem there will flood #4, but I haven't had any issues there yet. I looked at replacement fuel pumps and about fainted, good thing there's aftermarket.

By this. I only did a real quick compression test with a half dead battery before starting that yielded 150. It was less than 100 before.

That's interesting. In the automotive world the rearmost cylinders are always hurt the worst from overheating because of what I said, it takes longer for coolant to circulate around them. Just goes to show that an engine is not an engine, they behave different when turned on end. I did take a close look at the oil and it was right on the money as far as level goes, but I did change it after running for a couple minutes. I think lack of lube would've been evident by scoring on the piston or bearing damage. Everything in this engine was beautiful, plastigauged right at .002.

Yep, no smoking gun that I've found. Injectors tested and flow checked, no problems. That is the only thing I can think of that would've only affected just one cylinder. My only hypothesis is that perhaps #4 was fed a straight shot of ethanol that settled in the rail, being that it is fed from the bottom with a check valve right under #4 injector, but I think that is a stretch. Overheating would make sense since the thermostat is on top of the block, #4 is the last to get cooling water, but there was no scoring or discoloration on the piston to back that up, and #3 looked identical.

That's what you read on the internet. Proof is kind of in the pudding here though, this one only having 300 some hours and being hurt pretty bad. It remains to be seen if I'm happy with it. I don't even know if it'll spin a prop yet.

We'll see I guess. There's still quite a discrepancy in your experience and everyone else. People seem to think the world of them and the hour meters run into the thousands. Bad fuel is the only cause of the failure that I can see. I opened up the FSM and dumped what was in it, looked pretty brown, but the motor has been sitting for months at this point. I isn't charging so I've got to figure that out. Might need to bring that alternator to a rebuilder.

I'm selling, not buying. Truth be told I don't really use it that much.

An opportunity sort of popped up and I'm letting some things go to get some money together. Livescope is one of them. It's about 6 months old, no issues, just the transducer and black box. I have the original packaging and the trolling motor mount as well. I figure $1200 is a fair price since they're $1499 plus tax.

Mud bees had clogged the tell tale hose on either side of the tee, and then somehow made it through an 18" bendy hose and managed to also plug the inlet on the FSM. Got them all cleared out and it's working well now. Not much else to do until I get the cable adapters.

I tried muffs first with the same result. Steady stream out of the water pressure hose but a few drips out of the tell tale. This motor also has a flush port, I'm not sure if you're able to run the motor with it, but when I tried using that, it acted like there was a blockage and there was no water exiting the lower unit. The manual shows that water first goes around the exhaust manifold, which is where the supply for the FSM is tapped in, the telltale is tapped into the outlet from the FSM. Mud daubers may have gotten into that FSM while it was off. There is also a screen on the inlet fitting that I should check.

That's that. I was going to try and hit the water tonight, but I don't have the Merc cable adapters for the controls. It is pumping water but there is some sort of blockage in the telltale circuit. Whizzes like crazy out of the water pressure hose. I also goofed and forgot to install the retaining ring on the upper crank seal. Not a big deal, just need to pull the flywheel again.

Is it shooting tennis balls or something, or just blanks?

Got the long block assembled last night. Had a lot of trouble with ring compressors, finally ended up trying a tapered Wiseco sleeve that worked like a charm. Just need to clean the cams up and get everything timed, then the powerhead will go back on. Hopefully will be ready to see if it pops tomorrow. I swapped in .015 thinner valve shims on the #4 intakes and the clearance came out perfect, so that's taken care of.

I don't think I've ever paid any attention. Always between some variation of between the fingers of my right (dominant hand). Different rods require different positions too. I have a rear seat 10' Ozark crappie rod, which I like, but found the length and grip position to be a bit awkward. Not used to working with long rods. 😁

While going through and checking all of the valve clearances, I found that both intakes on #4 are way too tight, like zero. Even swapping a shim from the exhaust doesn't bring them into spec. Measuring the stem heights, #4 intakes are both about .015 higher than the rest. That is another conundrum, seems like the detonation that was happening in #4 also pushed the valves into the head quite a bit. I need to order new rod bolts anyway, guess I will get some .015 thinner shims and see how the clearance comes out. At least they aren't real expensive.

Injectors tested fine. At least I know they're all good now, but I would've liked to have a definite answer to the failure. Just waiting on the head gasket and the controls now.

Already got a head gasket, powerhead gaskets, thermostat, and controls on the way. I haven't found a lot of NLA parts, but the gaskets are high. Wonder if it's only the Yamaha made 4S Mercs that don't have any parts available. This is a baby Verado, without the supercharger.

Yep. General rule of thumb on a three ring piston is to clock each ring gap 120* apart when you put them in the block. I saw it mentioned in the service manual for the Merc but I forget what it said. Im going to run the injectors down to Sho-me speed and have them cleaned and flow tested.

I don't think I've ever seen a 4S with pinned rings. I thought it was exclusive to 2 strokes, so the ring gap can't migrate into a port opening, where bad things could happen. These are not pinned, in my last pic you can see both ring gaps, they're free to rotate.

As far as I can tell it's installed the same as the others. There is no marking or any sort of bevel/chamfer on it. This is #3.

I agree with you there. I think it's wonderful that they're stepping up to address the way wages have stagnated for decades, but simply raising the minimum wage is not the way to do it. It's a slap in the face to many.

I'm not sure how long it was ran with a dead/dying hole. I'm sure as it was failing it began to burn more and more oil. The middle ring is stuck because if how badly the ring lands are eroded.

Took a little time after work today and pulled the powerhead. The bearings in the bottom look perfect. Got a couple photos of #4 after I pulled it out.