Whelp....blew the @!@#% powerhead. :-|

[bbarthelt]

Hi guys. 1996 200 EFI, Serial. 0G361511

A local shop rebuilt the VST saying it was corroded / varnished from ethanol. Had repeated issues with flooding, which took them several visits to sort out. Last visit, they said O-rings, and they were confident it was solved. I did some test runs after that, and all seemed normal, but i didn't run around much.

Took it out today to practice for a big tournament. On my 3rd run to a spot I heard "TICK TICK TICK" then it shut down. I glanced back and came off the throttle the instant I heard the noise, and I could see my cowling getting rammed upward. Stopped the boat, took the cowling off. The powerhead is destroyed. Metal everywhere. Control arms on both sides broke clean through. So obviously, this power head is done for.

A buddy towed me in and there was a shop at the ramp. He was willing to take a quick look. He was able to verify that the right amount of oil seemed to be in the fuel (so not an oil delivery issue). He shined a light into the gaping holes in my powerhead, said the control arms were blue, which indicates overheating.

My question to this group: is there anything about a VST rebuild that would have caused this? I had a new lower unit and impeller, so doubting that failed. I'm certain the shop will conclude they are not at fault. Is there any way to determine if they are at fault?

Thanks as always.

[lpugh]

Control arms? Do you mean connecting rods
How do you know the correct amount of oil is in the fuel
If the rods are blued on the big end I would be checking the oil lines for proper connections and how much oil is in the tank

[bbarthelt]

Im sorry, yes, connecting rods. His test wasn't very scientific. He verified that all the oil tanks were appropriately full (they were), and disconnected one part and drained some fuel into a cup, just to see that the gas had the blue tint of the oil.

[kls2020]

Which two connecting rods failed ? The fuel injectors are fired in pairs 1&2 , 3&4 , and 5&6 . If the rod damage coincides with a particular injector pair it could mean an issue with fuel delivery being too low resulting in both lean fuel mixture and low lubricating oil as well for those 2 cylinders . Have you overheated this motor recently due to a faulty impellor or poppet valve ? Those connecting rod bearings if still stock are plastic caged an overheated engine can make the plastic brittle leading to a premature bearing failure .

[bbarthelt]

Thanks KLS, yes, it was one pair that went. I don't know how they're numbered, but you can tell it is one pair, toward the top front of the engine. Do you think the rebuild of the VST system could have been a factor? I really just want to know if I have a case that this might be the shop's fault. I don't want to screw them by any means. If it had nothing to do with their work than it's on me. I just don't want to get screwed either.

[123trentm]

injector, ecu or oil system failure

[EuropeanAM]

Probably ECU... though the others are possible (keep in mind, an oil failure will have relatively similar catastrophic damage in ALL cylinders). Bearings tell the tale if it's an oil problem.

An injector is normally going to be a single-cylinder failure.

[bbarthelt]

It looks like the bearing went in #2 cylinder according to the mechanic next to the launch ramp. ECU was a fairly new Brucato, set to stock. During the debugging of the VST, the old ECU was blamed (now known to be incorrect). Finding a replacement at a reasonable price was nearly impossible so I went with the Brucato. That obviously did not solve my prior issues, later determined to be a corroded VST system. But after I just left the Brucato in. I guess the consolation is when I part this engine out I have a perfectly good Merc ECU and a perfectly good Brucato to sell (silver linings).

[kls2020]

When was the last time you had your fuel injectors cleaned and flow tested ? If you had contamination issues inside your VST and the fuel pump inlet filter was damaged or compromised debris from the VST could have made its way to the inlet screens on the fuel injectors reducing fuel delivery . Also if an injector is hanging up and not working properly same result . Either way getting your injectors cleaned and flow tested is cheap insurance .

[bbarthelt]

I believe it was 3 years ago (last injector service). How often do you recommend?

The other important thing I thought of: After they rebuilt the VST, I had flooding issues. Wouldn't this have it running too lean? It took several visits for them to determine the cause, and i. I'd take it in, they'd test a theory, I'd use the boat Turns out they re-used the O-rings after the VST rebuild, and they were leaking so they finally figured it out. But I was using the boat in between. Each time, the boat would run great at first, and throughout a tournament day, it would flood more and more, and need more and more throttle to keep it idling. Now I'm wondering: the combination of them reusing the O-rings (causing leaking) and me still using the boat (running it with a lean condition)...could this have, over the course of 4 or 5 iterations, brought about this issue?

[lpugh]

Running lean would cause a piston failure and could have in turn caused a rod to fail, loss of lube probably would have caused a Crank/rod failure first.
Take some good pictures of the crank, rod and pistons from different angles and post them.
Flooding means you have a very rich condition, though it is possible to have a vst float valve issue that could be rich at idle and lean at high speed, good pictures of the piston would allow us to tell if it was in fact a lean failure, piston skirt, crank and rod to determine a lube problem
Could be it was neither one
Lesson learned here is, don't run it when you have a known issue until repaired

[moetorola]

Thanks KLS, yes, it was one pair that went. I don't know how they're numbered, but you can tell it is one pair, toward the top front of the engine. Do you think the rebuild of the VST system could have been a factor? I really just want to know if I have a case that this might be the shop's fault. I don't want to screw them by any means. If it had nothing to do with their work than it's on me. I just don't want to get screwed either.

$#!t happens move on, as far as filling law suit.

If you have to ask here for help to determine if a shop "might" be at fault, you have no case. It should be clear the shop is at fault, in this case it... is not.

Even guys that had an issue and it was clearly obvious that a shop made a mistake that caused damage, was still a 50/50 shot at getting some or all there money back.

No one here can 100% say what caused the problem without physically looking at it. And even looking at it, may not be 100% sure.

You could ask the shop and see if they can meet you half way, or a discount on a new or used motor or power head. Don't be rude, blame them, or threaten them. Most shops want to keep there customers.

Keep in mind, if this shop has been in business a while. This is likely not there first time in this situation with a customer.

Of course this just my opinion!

[bbarthelt]

In case anyone was curious, I ultimately took the motor to another shop. They said the injector for the failed cylinder was blocked with crud. I can't help but suspect it was crud from the redone VST. Does that sound like a logical conclusion? Nothing I can do about it now though. I sold the boat, and blown motor for parts. I kept the brucato, and have it for sale on here.

[lpugh]

In case anyone was curious, I ultimately took the motor to another shop. They said the injector for the failed cylinder was blocked with crud. I can't help but suspect it was crud from the redone VST. Does that sound like a logical conclusion? Nothing I can do about it now though. I sold the boat, and blown motor for parts. I kept the brucato, and have it for sale on here.

If the injector was blocked there would no oil supplied to that cylinder, thus a crank/rod failure would occur. Again if blocked that also mean no fuel in that cylinder, no fuel means no combustion and no heat to cause detonation and piston top meltdown, Restricted would mean insufficient oil and lean AFR possible causing failure on both sides

With the VST issues the entire fuel system should have been cleaned and tested
This was very a predictable event

[bbarthelt]

Thanks Leon. In your opinion, shouldn't cleaning the fuel system simply been something the mechanic knew to do as part of the job, or is it on me for not asking them to?

[EuropeanAM]

Thanks Leon. In your opinion, shouldn't cleaning the fuel system simply been something the mechanic knew to do as part of the job, or is it on me for not asking them to?

It's pretty easy for any of us to read this thread and say "yeah- the VST should have been disassembled and cleaned, and the whole fuel system refurbished". That's called "hindsight is 20:20".

I would hope that a reasonable technician would have some viable REASON to tear into the VST, including (but not necessarily limited to):

-Dirty or debris-laden fuel drained from VST
-Low or no fuel pressure
-Fuel Pressure Leakdown
-Inadequate fuel volume in VST
-HP Fuel Pump not functioning properly
-Leaking fuel from VST or Overflow

I'm sure that "today" you would gladly have bought a whole different fuel system to avoid a powerhead failure... but in reality, backing up to earlier services, you probably would have wanted some really good explanation for spending your hard-earned money.

Sorry- don't like playing "devil's advocate" but the reality is that even those of us that know the system well enough to disassemble it blindfolded do NOT have "x-ray vision" to see inside the system. We must rely on tests and deductive reasoning.

[lpugh]

Thanks Leon. In your opinion, shouldn't cleaning the fuel system simply been something the mechanic knew to do as part of the job, or is it on me for not asking them to?

In my oppinion anytime the vst is contaminated as described the intire fuel system should be serviced, If I was a marine dealer under that circumstance I would insist on it. But I dont know all the facts and I am not a marine tech, I am a automotive tech with a little knowledge with mercurys

[JOE54]

+1 ^^^^^^^ Im with LEONE on that one just good basic repair knowledge eliminating repeat failure or preventing possible engine failure and based on test results also