What would cause this? 2001 951 DI

[docdrs]

like the title says 270 hrs


DSCF0817 by docdrs, on Flickr

 

[El Toro 33809]

Over heating/lack of lubrication.

 

[Dr Honda]

That piston was "Stuck"... or lightly seized.

So...

1) Over heated
2) Run Lean
3) Lack of oil


If you are on the edge of running lean.... the PTO cyl will be the first to stick.

 

[docdrs]

Over heating/lack of lubrication.

Yes, but what would be the possible cause? Oil is injected into the crankcase which appears to be occurring as the crank is being lubricated on manual rotation. Could it be ring wear and loss of lubrication? or is there something else? should I be pulling the oil pump? could it be a lean injector? what is usually or the causes of this? thanks

 

[El Toro 33809]

The first and easiest idea is it ran out of oil. With the safety checks built in place that is unlikely though. I don't know much about DI, so I can't comment on that. And I'm under the impression that the oil pumps are fairly bulletproof. Let's see what Doc Honda has to say.

 

[docdrs]

That piston was "Stuck"... or lightly seized.

So...

1) Over heated
2) Run Lean
3) Lack of oil


If you are on the edge of running lean.... the PTO cyl will be the first to stick.

What else should I be looking at during my rebuild. Could it be stuck ring from poor winterization? Lean injector? I have never run out of Oil. Are there any tests I should perform? Thoughts? Thanks.

 

[sphornets]

same thing just happened to mine. lack of lubrication but I dont know who/what/when/where/why. only 50 hours on the motor but it had been stored for 8 years and not maintained prior to storage.

 

[Dr Honda]

If the compression was low in that jug... (From rusty rings) then yes.... that can cause it to stick. Basically, once the rings stop sealing... the hot blow-by gasses will over heat the skirt, and displace oil. A "Low compression" melt down will normally look like lack of oil. BUT... the answer lies in the crank bearings. If they are wet with oil... the injection was working.


One other thing... if you had a case leak... or a crank leak (bad seal) then that will cause that jug to go lean.

 

[docdrs]

If the compression was low in that jug... (From rusty rings) then yes.... that can cause it to stick. Basically, once the rings stop sealing... the hot blow-by gasses will over heat the skirt, and displace oil. A "Low compression" melt down will normally look like lack of oil. BUT... the answer lies in the crank bearings. If they are wet with oil... the injection was working.


One other thing... if you had a case leak... or a crank leak (bad seal) then that will cause that jug to go lean.

The crank looks good lots of oil on it when turning by hand, I only had 100 psi on the other piston and I think when I bought the DI it had 140 psi on both cylinders and I think that is what they are supposed to be ?. my machine shop said lack of oil would toast the crank , he said to look at the fuel injectors as if that one was not putting enough fuel into the cylinder it could cause a lean condition and piston meltdown. How do you test the injectors? what flow rate is suppose to be running thru them? or should I just buy new ones?