Quick Question about Bottom end

[JKoepsell]

Hello, I am currently in the process of getting a new bottom end. I was riding yesterday and suddenly heard a very loud rattle. I took off the cylinder last night and there is a lot of free play in the rod. I plan on splitting the cases tonight but I would just like to know why this happens. After I took off the cylinder there was a handful of black crap, dirt or metal, dunno, just laying on top of the crankcase. It just looked very dirty. I recently did a top end(about a month ago) and when I took the cylinder off then, it was much cleaner. Maybe a speck or two. How did it get so bad so quickly? I have an 03 KX 125. I keep my air filters relatively clean. Is it just normal wear and tear? Is there anything I can do to lessen the chances of replacing my bottom end again? Its kinda 'spensive....

Oh yeah, something else wierd to me.... The gap on my spark plug was VERY small.... It was definatly bent because I compared it to another of the exact same kind. Could the piston have hit the plug??? There weren't any marks in the piston or spark plug.

[ossagp1]

Pistons hitting plugs are pretty hard to do and stay in one piece,,but to be honest I havent had one of your models cylinder heads in my hand.

Reality time: A three to 4 years old lowerend is an old one on most 125's. I wont go into mix ratios etc, but most of them that wear out too fast (50 hours or so) are run with too little oil imo. Again though, a 2003 would be hard to find with 150 hours that wasn't getting to the point of needing some attention there. FYI lugging them is as hard or harder on them if you are running mixes in the 40-1 range or even 32-1 range than running them a little on the high side. If you get into water very often, that is also hard on them as it washes away what lubrication there was.

[JKoepsell]

Yeah, I was usually running it around 40 or even 50 : 1. I was using synthetic stuff though, MC-1 which recommends it. I guess spark plugs are cheaper than top and bottom ends though. Me and a friend are taking it to a shop we have permission to use and are gonna wash the motor in an "engine bath". Is that okay? I will have to lube it all up afterwards right? What do they wash it with?
Couldn't dirty air filters contribute to dirt in the motor as well?
As for the plug, I was looking at it and it looks like it would hit the cylinder head before the plug. Dunno why it was so bent.