Turd Polishing

[fishinwrench]

Good job, bro !    

I hope she lives a few trips for ya.  😊

[MrGiggles]

11 hours ago, fishinwrench said:

Good job, bro !    

I hope she lives a few trips for ya.  😊

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.

[fishinwrench]

4 hours ago, MrGiggles said:

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.

Thousands?  There's a huge exaggeration factor going on there.  But that's ok, I'm glad you're happy with it.  That's all that truly matters.   

One thing I've always credited the 4S motors for.....is that THEY'LL USUALLY LIMP YOU BACK HOME.    Whereas 2-strokes have no problem at all leaving you stranded far from your truck/trailer.  😅

[MrGiggles]

3 hours ago, fishinwrench said:

Thousands?  There's a huge exaggeration factor going on there.  But that's ok, I'm glad you're happy with it.  That's all that truly matters.   

One thing I've always credited the 4S motors for.....is that THEY'LL USUALLY LIMP YOU BACK HOME.    Whereas 2-strokes have no problem at all leaving you stranded far from your truck/trailer.  😅

 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.

[fishinwrench]

2 hours ago, MrGiggles said:

his one only having 300 some hours and being hurt pretty bad.

Cause of the failure is still undetermined?  Pardon me if I haven't kept up to speed on this project. 

And yeah, just because you spent 8 hours out on the water in a fishing boat certainly doesn't mean that you put 8 hours on the motor. 🙄 

 

[MrGiggles]

17 minutes ago, fishinwrench said:

Cause of the failure is still undetermined?  Pardon me if I haven't kept up to speed on this project. 

And yeah, just because you spent 8 hours out on the water in a fishing boat certainly doesn't mean that you put 8 hours on the motor. 🙄 

 

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.

[rps]

Every time I come back to this thread, I realize two  things. I do not know squat about engines and rebuild. And I totally enjoy reading the progress to a polished turd.

[fishinwrench]

8 hours ago, MrGiggles said:

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

#4 is your coolest running cylinder (heat rises).   #1 is always the hottest (that's why the temp sensor is placed near there).     You will hardly ever see lower cylinders fail first from an overheated outboard, it's always #1 & #2 unless it overheated from friction as a result of a lack of lubrication......and in the case of a 4-stroke I would guess contaminated oil.     (Fuel in the oil)  of which 4-stroke outboards are FAMOUS for.  

Here ya go....

https://www.boatingmag.com/how-to/making-oil/#:~:text=Your engine could be “making,fluid intrusion of the crankcase.&text=Check your oil regularly.,oil before slipping the lines.

[MrGiggles]

4 hours ago, fishinwrench said:

#4 is your coolest running cylinder (heat rises).   #1 is always the hottest (that's why the temp sensor is placed near there).     You will hardly ever see lower cylinders fail first from an overheated outboard, it's always #1 & #2 unless it overheated from friction as a result of a lack of lubrication......and in the case of a 4-stroke I would guess contaminated oil.     (Fuel in the oil)  of which 4-stroke outboards are FAMOUS for.  

Here ya go....

https://www.boatingmag.com/how-to/making-oil/#:~:text=Your engine could be “making,fluid intrusion of the crankcase.&text=Check your oil regularly.,oil before slipping the lines.

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.

[fishinwrench]

2 hours ago, MrGiggles said:

 

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

So the compression loss was caused by what?    Leaky valves?

What are the compression readings NOW?