Hours between rebuilds?

[thirdgenlxi]

Just asking out of curiosity, being this is my first 2 stroke dirt bike (well first dirt bike period). I had recently read a thread over on thumpertalk and a guy said he had 104 hours on a piston on his CR250, and people were literally going nuts that he had let it go that long. Now I know the CR and the KDX are two completely different bikes and engines, so I know it's all relative and the CR is likely gonna need stuff before the KDX will. I've only had my bike a little over a year now (March 2015) but I do tend to ride quite a bit, and have accumulated a few hours on it already

Taken tonight.... it's a little higher now as I was riding home from work, I just took the pic cuz of the all 3's, lol. Mileage is right around 4500. Both hours and mileage are just in the time I've had it, as it had no hour meter or odo when I bought it.... the guy I bought it from rode it for 2 years before that and didn't do anything to it (as far as rebuilds go), and he doesn't even know if the guy before him did either



I haven't done anything to it outside of regular maintenance stuff..... carb float valve and a set of front wheel bearings have been the only real repairs I've had. Replaced the reed valves with a set of Boyesen Pro Series reeds just because. I'm not having any problems with it whatsoever.... compression test shows 170 psi, it starts first kick every time both hot or stone cold, runs like a dream, butter smooth and quiet (stock exhaust still) and has plenty of power, trans oil stays clean, etc.... nothing seems to be wrong, and bike has been amazingly reliable (and still is). I'm just curious what the normal interval was people usually run them to.... it seems like our KDX's will run just about forever, lol. I hate tearing into something that's running perfectly fine..... But I don't want to be riding a ticking time bomb either



From what I gather I think the plug is about right too (it's actually a tad darker, the flash brightened it up some)




Thoughts?? It's a 2000 KDX-200, BTW.... ridden both dirt and street

[ohgood]

pull the pipe and look at the cylinder/piston. inspection of both takes five minutes to remove the pipe.

the power valve is likely carbon coated, which causes failures if not cleaned regularly ( once every few years) but otherwise kdxs will run for decades.

that looks like a fun fun fun machine

[thirdgenlxi]

Ohhh it most certainly is! hahah

Just went out and pulled the pipe.... i needed to put some new o-rings on it anyways. Pics kinda suck as they're from my little borescope camera, but should be able to get an idea

[sammydogjj]

Same here, my bike has had three owners, and I myself have already put around 600 miles in it. Only "major work" I have done is a a carb rebuild, new clutch plates, and wheel bearings. I'm gonna look at my cylinder/piston while I have the pipe off this weekend.


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[Sullyfam]

Piston looks a bit rough with blow by. Top end wouldn't hurt.


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