What happened to Isabella's Engine?

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ionbeam said:
A bit more about the balancer.
The adjustment is just for gear lash and operating noise, it does nothing for the actual balancing. Also, the FSM doesn't mention this but there are TWO alignment marks and it's easy to align to the wrong mark which results in an engine that runs like a Sherwin Williams paint shaker.

Depending on the ambition level of hppants, he could use a Plastigauge kit and measure the rod bearing's free play. With the rod cap removed, clean the journal and place a strip of Plastigauge across the journal. Put the rod cap back on and torque to spec. Remove the rod cap and see that the Plastigauge strip will have been squished flat. Use the gauge supplied in the kit to measure the width of the squished plastic. The width is directly proportional to the clearance and read on the gauge in thousandths of an inch.
Click to expand...
Agree. A dial caliper and operator won't have the ability to measure this. Plastigauge the only way to go here.

Also I'm definitely missing all the history of the engine failure, but I've seen worse than that #3 and engines running OK. Was it knocking?

 
Yes, what I was suggesting was what Ion mentioned using Plastigage to get the clearance between the crank journal and the rod bearing shell and then using the micrometer measure the crank journal diameter and compare to the other crank journals (#1, 2 and 4). If you could feel play in the #3 rod I think the Plasitgage will definitely indicate the slop in the rod you felt. Might be a final way to verify if that #3 rod bearing is bad.

 
I don't understand this all...but this thread is pinned in my world for future reference, to just be able to see the parts vs looking at a parts fiche is very informative to me.

THANKS.

 
Reading through this, I think I'd offer an opinion on the root cause. That gunk in the bottom of the oil pan is not from rain water. Rain water would stay separate from the oil and would be easily seen as bubbles of water sitting on oil or bubbles of oil sitting on water. What you have here is well emulsifide oil which would only happen if the bike were running with water in the oil. And it would have run for a little while like this. If only run for a short bit, it would have separated.

You also see oil in the water pump and some corrosion in the oil cooler. You don't see much wear on things like gears. They are still getting lots of lubrication even if there is water in the oil. These really only need an oil spray to keep them running fine. The killer damage are on parts with sleeve bearings that ride on a film of oil. They can't ride on a film of emulsifide oil.

If the bike has overheated a few times in the past and sometime ago, the overheating probably didn't have any effect on the metal parts or bearings. It could have had a real effect on seals and o-rings.

What you see on #3 sleeve bearings is a result of other issues. Maybe the end cause of the motor failure but not the root cause.

I'd guess. Engine slapping, banging and noisy cause by failing journal bearing.

Journal Bearing failed overtime due to water in the oil

Water in the oil due to failed Oil Cooler or break in head gasket between oil and water side.

Failed o-ring or gasket as a result of a few over heating sessions

Overheating caused by failed thermostat, low on coolant, poor attention and riding habits.

 
As to why the balancer isn't helically geared, helical gears introduce thrust loads.

I've seen discussions of the ST1300 foiks "smoothing out their bikes" by "adjusting the balancer," but as Alan pointed out, that external adjustment has absolutely dick to do with the actual balance function. The only way to "adjust" that is to remove the balancer and put it back in on a different tooth, which of course will make it worse. That adjustment might make the balancer run quieter, but smoother? No way.

But if placebos make you happy, then load up on 'em!

Also, hppants, there is another balancer on the rear of the engine, accessed from the top, a four-bolt cover plate in the valley between the cylinders and the tranny. You'd have to turn the motor back over, set it upright to find it, so you probably aren't too interested in it right now....
smile.png


 
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Also if you look at the groove on the journal bearing of #3, you see a nice smooth groove right where the oil is pushed in. Compare that against the "Oil Seal Failure" section in https://gipservice.gr/data/documents/PhThORA-KOUZINETON.pdf (link provided previously by other). Having water/steam in the oil as it hits the bearing could certainly count as something keep it from having a seal. Possibly even steaming the bearing.

 
Maddad - most excellent post. He's right - there was "milk" inside the water pump and inside the oil pump. That doesn't get there rainwater out behind the shop.

I'm going back up in the attic with my camera. Stay tuned....

BTW - I forgot about that "plasti-gage" thingie. I remember learning about that in shop class (back then we rode dinosaurs to work!). I'm not opposed to this, but let's see where we go.

I love learning about these things. The thought of doing this via the Internet with experts from all over the world is fascinating to me.

 
That sounds very plausible! It's clear that the thing has been abused and misused. Surprise it lasted as long as it did and appears to be , in general, in as good shape.

 
hppants said:
Goat - I'm at a loss at to how you could remove the last 4 bolts (especially the last 2) to split the case without removing the output gearing setup? Take a look at this picture - these are the bolts I was referring to. Again, I'm not arguing, but trying to learn.

Also, no groove felt with my fingernail on any of the crank journals. I think the crank is good.

IMG_3085_zps62532da1.jpg
Click to expand...
My apologies for the confusion, what I meant was you only had to remove the output gear (the one on the far left in that picture with the u-joint)

The one on the right (with the 32mm nut) can stay in the lower case half.

Here's a pic of my finger underneath the head of the bolt. The bolt is still captured beneath the gear, but the threads of the bolt are disconnected from the top of the case half:

SAM_0630.jpg


Same goes for the bolt trapped above the oil cooler:

SAM_0628.jpg


Probably a moot point for you at this juncture, just FYI for the other forum members unfortunate enough to have to split their cases.

Thanks again!

 
Goat - well done, much thanks.

Haven't gotten up in the attic yet. Seems SOQS (She of Queenly Stature) has other "plans" for my afternoon.

(sigh)

The lawnmower waits....

 
The more I look at those bearing pics and the 'white milk slurry' in the sump and oil pump, the more convinced I am that MADDAD has the right theme with what went wrong with this engine. Depending upon what the rod bearing clearance measurements turn out to be, I think it is very possible that if the source of the water in the oil was found and repaired and the engine cleaned of the water logged oil and fresh oil added, this enging might run for another 100K. I think the noise that was heard were the rod bearings being tortured due to the watered down oil slurry in the sump. That score mark on the #3 rod bearing doesn't look catastrophic to me just from the photos. Might be wrong but I'm a sceptic!!

that is a 'skeptic'!

 
Hornet Pilot said:
The more I look at those bearing pics and the 'white milk slurry' in the sump and oil pump, the more convinced I am that MADDAD has the right theme with what went wrong with this engine. Depending upon what the rod bearing clearance measurements turn out to be, I think it is very possible that if the source of the water in the oil was found and repaired and the engine cleaned of the water logged oil and fresh oil added, this enging might run for another 100K. I think the noise that was heard were the rod bearings being tortured due to the watered down oil slurry in the sump. That score mark on the #3 rod bearing doesn't look catastrophic to me just from the photos. Might be wrong but I'm a sceptic!!

that is a 'skeptic'!
Click to expand...

I would have tended to agree...based on the photos. But weren't there compression and power issues that were symptoms...thus the reasons to take it to the mechanic in the first place? New oil wouldn't have fixed those symptoms.

 
Nope, your 100% right on the compression issues and perhaps that was the area of the water leak into the oil! Just a head gasket problem? I don't know. Maybe a crack due to over heating? Could be, but some easy tests might have indicated that! Well, what is done is done as they say!!

 

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