Just bought a second hand '03 220R.
When I got it home (100 miles road riding on stock gearing - fairly high revs, but not flat out), I noticed the gear oil was slightly low ('low' mark on the sight glass) and very dark. As I happened to have a spare 3/4 bottle of 10w/40 sitting around from my road bikes, I drained the old oil and refilled. First thing that concerned me was a slightly cloudy layer on top of the oil (no white gunk or other obvious contamination on the filler cap), but then I didn't know how long whatever it was had sat in the tranny, so assumed it was simply ancient oil.
After getting a couple of hours practice riding on it today, I noticed that although the trans oil level seemed fine, the fresh 10w/40 was now black, and again appeared to have a slightly misty/cloudy layer on top.
A bit of searching on this forum leads me to suspect this could be a bad crank seal or seals. Other reasons for suspecting this are:
- The aftermarket exhaust silencer had a thick, greasy strip of black oil/gunge all the way along the bottom, like half-burnt oil had leaked out of the pipe and run down the bottom.
- when I washed the bike after getting it home, I noticed a small amount of oil/oily gunk on the bottom and front of the cases (under the expansion chamber area).
- Bike is quite smoky. Did about 4 hours riding on it home at 50:1 before I downloaded a spec sheet and switched to the recommended 32:1 (Putoline TTX fully synth). Don't know how it's been jetted, but it starts well and certainly doesn't lack power. No huge clouds you can't see through, but a definite white smoky haze whether cold or warm. It doesn't like neutral throttle very much and surges/diesels. Again, not sure if that's normal.
- Not very good fuel economy - about 25mpg at a guess.
- Coolant overflow tank is clear (appears to have been filled with water not antifreeze), so I doubt the _apparent_ oil contamination is coolant circuit.
- Bike may have been run over 5k miles with no rebuild, based on the removed odometer I was given with it (has KX forks and yokes, no speedo drive, so no real idea of the mileage/hours).
I'd appreciate some advice from you experienced KDX'ers - should I worry about this, or am I just being paranoid? Could this just be normal "cooking" of the transmission oil? Should I just stop riding it now? Bike seems to run great in terms of starting, power, light-switch throttle response. Obviously has run at least 6 hours without any sign that it's fouling the plugs. Slight rattle/buzz from the engine which I understand is normal KDX noise, no other weird vibration. The only other problem I noticed was clutch drag, which appears to be intermittent. (On my only other dirt bike, a '76 TY, this is often caused by not riding, causing the exposed friction plates to dry out, so it could just be the last owner hadn't ridden it much.)
Guess I'm not sure whether I should start pulling the motor and sending it off for a rebuild, or whether I should just keep riding and see if something obviously nasty develops.
Any suggestions?
When I got it home (100 miles road riding on stock gearing - fairly high revs, but not flat out), I noticed the gear oil was slightly low ('low' mark on the sight glass) and very dark. As I happened to have a spare 3/4 bottle of 10w/40 sitting around from my road bikes, I drained the old oil and refilled. First thing that concerned me was a slightly cloudy layer on top of the oil (no white gunk or other obvious contamination on the filler cap), but then I didn't know how long whatever it was had sat in the tranny, so assumed it was simply ancient oil.
After getting a couple of hours practice riding on it today, I noticed that although the trans oil level seemed fine, the fresh 10w/40 was now black, and again appeared to have a slightly misty/cloudy layer on top.
A bit of searching on this forum leads me to suspect this could be a bad crank seal or seals. Other reasons for suspecting this are:
- The aftermarket exhaust silencer had a thick, greasy strip of black oil/gunge all the way along the bottom, like half-burnt oil had leaked out of the pipe and run down the bottom.
- when I washed the bike after getting it home, I noticed a small amount of oil/oily gunk on the bottom and front of the cases (under the expansion chamber area).
- Bike is quite smoky. Did about 4 hours riding on it home at 50:1 before I downloaded a spec sheet and switched to the recommended 32:1 (Putoline TTX fully synth). Don't know how it's been jetted, but it starts well and certainly doesn't lack power. No huge clouds you can't see through, but a definite white smoky haze whether cold or warm. It doesn't like neutral throttle very much and surges/diesels. Again, not sure if that's normal.
- Not very good fuel economy - about 25mpg at a guess.
- Coolant overflow tank is clear (appears to have been filled with water not antifreeze), so I doubt the _apparent_ oil contamination is coolant circuit.
- Bike may have been run over 5k miles with no rebuild, based on the removed odometer I was given with it (has KX forks and yokes, no speedo drive, so no real idea of the mileage/hours).
I'd appreciate some advice from you experienced KDX'ers - should I worry about this, or am I just being paranoid? Could this just be normal "cooking" of the transmission oil? Should I just stop riding it now? Bike seems to run great in terms of starting, power, light-switch throttle response. Obviously has run at least 6 hours without any sign that it's fouling the plugs. Slight rattle/buzz from the engine which I understand is normal KDX noise, no other weird vibration. The only other problem I noticed was clutch drag, which appears to be intermittent. (On my only other dirt bike, a '76 TY, this is often caused by not riding, causing the exposed friction plates to dry out, so it could just be the last owner hadn't ridden it much.)
Guess I'm not sure whether I should start pulling the motor and sending it off for a rebuild, or whether I should just keep riding and see if something obviously nasty develops.
Any suggestions?
