Sump Strainers

[Stretch67]

So... I picked up a '98 XR400 a couple weeks ago. It started on the first kick, ran smoothly, no smoke. So she followed me home.
Cool.

Oil & filter change went smoothly, as did a cleaning of the frame downtube strainer... a very few small bits, but nothing major for
a 15-year-old bike. I didn't check the sump strainer quite yet, as I didn't have the side-cover gasket, and didn't have any other
reason to go in there.

Further mechanical meanderings revealed an overly-stretched (don't blaspheme) cam chain. The tensioner spring is good,
but has no more travel. Okay, that's two reasons to go into the right side of the case... cam chain and check the oil strainer.








Hol-ee shiiiit!


The ruler wasn't in there, really.

This pile of scrap isn't from my piston. The bike starts and runs with no smoke, and there wasn't a speck of debris anywhere
else in the entire sump... just in the strainer cavity.

There is a line of black RTV between the cylinder and case, indicating a reassembly somewhere along the line. I believe after a
previous piston was nuked, a mechanic didn't know about the existence of a sump strainer in Honda thumpers and let it pass
unnoticed.

I was familiar after having done some kick-starter work on my beloved old XL250 years ago.

I removed my oil pump and back-flushed the pick-up tunnel, then flushed out the debris with kerosene in a large syringe. Medical
types will recognize this procedure as 'lavage'. I lavaged the hell out of it. My sump is now clean enough to eat off of...
if you don't mind kerosene residue.


So... a kind note to mechanics out there: Please look for, check, and clean sump strainers, especially after major engine work.

[StevenD]

Are you sure its all old piston bits? Nothing magnetic?

[RideFreak]

Nice move cleaning that crap out of the motor.

When I purchase something used that has a motor, I naturally assume the worst, esp if it's been apart. I probably wouldn't have purchased it seeing that it's been apart and the mechanic (sic) used RTV to seal up the cases AND decided to leave a worn CC in there. Your picture is further proof of concept. Any mechanic worth his salt will flush out the motor in the event of a componet failure such as that. I'd say you're very lucky that the motor ran and still runs as well as it does.

Lots of hacks out there.

[clapped_r6]

nice find.

at the risk of starting another ktm bashing thread, i kinda like how my new-to-me rfs 450 has 2 strainers that are very easy to get to.

[Shooter1]

That picture scared ths shit outta me and I ain't scare of nuthin'!

Good luck with the new bike.

[kubiak]

dang!

[JensEskildsen]

Daymn... Mine has always showed up spotless, thank god. I would have shit myself if all that stuff came out of my bike

[michael1968]

Originally Posted by Stretch67

The ruler wasn't in there, really.

Haha, win.

Good luck with the bike.

[Shooter1]

What is the big chunk in the top LH corner. For Gods sake that's gotta be something serious doesn't it??? . I changed my oil on my KTM 620 once a number of years ago and found one small pc of what looked to be the end of a cotter pin on the drain plug magnet, about the size of the tip of a lead pencil. I was nervous as a whore in church about that but the consensus was just to go ahead and ride it, so I have and it still runs OK and doesn't make any funny noises, (knock on wood). Hopefully you have the same luck.

[Stretch67]

Originally Posted by Shooter1

What is the big chunk in the top LH corner. For Gods sake that's gotta be something serious doesn't it??? . I changed my oil on my KTM 620 once a number of years ago and found one small pc of what looked to be the end of a cotter pin on the drain plug magnet, about the size of the tip of a lead pencil. I was nervous as a whore in church about that but the consensus was just to go ahead and ride it, so I have and it still runs OK and doesn't make any funny noises, (knock on wood). Hopefully you have the same luck.

It's a piece of piston skirt a bit bigger than a man's thumbnail. You can also easily recognize the piece of piston ring down near the ruler. Some of the pieces are unrecognizable chunks of slag, I presume from the top of the piston as it melted down. Other pieces are fractured from the piston, and others are bits of steel from the rings.

Honestly, I'm not worried about the engine as it sits now, as it ran perfectly even before I tore into the strainer here. I just wanted folks out there to know and be on the lookout for sump strainers. Like RideFreak said earlier, "lots of hacks out there".