2001 DRZ 400 Engine Bearing Noise Help???

Hi all,

I have a 2001 DRZ 400S with 6500 miles on it. I put it away last winter fogged the motor, fuel stabilizer, etc., This year when I took it out I noticed what appears to be a grumbling that comes in and out (bearing perhaps). It is coming from what appears to be deep inside the left side of the magneto cover. I can't hear it when the engine is cold but it gets more pronounced as the engine warms up. It also doesn't seem to be related to engine RPM. Also it started after the bike sat for 4 months - it wasn't there when I put it away for the winter. I don't think it is the water pump as it seems to be coming from the other side of the magneto cover.

Any ideas? I am hoping this is a problem other DRZ owners have seen.

Thanks in advance.

I looked at it a little closer today and it is definitely coming from the clutch side and not the magneto side. It sounds like it is right below the clutch - not in the cylinder.

I only hear it once the engine is warmed up and it doesn't matter if the bike is in gear or in neutral.

I drained the fluids and pulled the clutch cover. I noticed when I drained the oil there was a small amount of foamy oil. I haven't really run it since last fall so I don't know if this is typical condensation or a leak from the cooling system. The cooling system fluid looked completely pure.

I took some pictures and the foamy oil seems to be concentrated near the top of the engine. The water pump bearing feels normal so I don't think that could be it but I don't know.

Question 1: is it normal to see some milky oil after a layup?

Question 2: what should I check next? Am I going to have to pull the engine and feel every bearing until I find a culprit?








Milky oil is from water. In this case fogging your motor would not have helped, fogging is more important for two strokes since the fuel goes through the crankcase. I can't say where the water is from. I would think in Michigan the air is pretty dry in winter, unless you had the bike in a damp place. It is hard for me to believe this much water is from condensation. With marine engines the oil is designed to absorb some water. I don't know about the oil you were using. I suspect the oil floated above the water (water and oil don't mix unless there is a detergent) and whatever steel parts are in the lower part of the crankcase are rusted (bearings). Surface rust would wear off without you noticing. I fear you problem is going to be more intense. Someone else may have a better idea. I recommend you have someone look at it. Our pull it apart yourself in a clean area and keep everything organized.

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