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Plastic oil pump gear .

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Ive had a problem with the oil level on the dipstick on my 2008 DRZ400.

When i bought the bike it showed a low level on the dipstick, so i topped it up.

It did it again , so i topped it up again, about 100ml each time.

I was suspicious and drained the oil , it had 3 litres in it ????

I noticed the frame oil was clean but the engine oil dirty.

I pulled off the side casing and clutch, to find a stripped plastic gear, which drives the geared oil pump.

Because most of the oil stayed in the sump, and the cam chain lifted some oil up to the top of the engine, I've got away lightly.

Moral of this story is, if you have a suspicious oil level on the dipstick, and can't see turbulence down the dipstick hole, check this gear ( or the oil pump).

It cost $24 AUD to replace , but if not picked up early would have cost a lot more.





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Did you remove the cam journal caps and inspect the journals for damage?  If not you should, that is the first place damaged when you have no oil flow.

The plastic idler gear is commonly damaged in one of three ways.

  1. Improper install the clutch basket after it was removed..and the damage done is not often immediately noticed... but the gear is fractured in ham fisted attempts to install the basket and then later the gear teeth break off.
  2. Trash loose in the motor gets caught up between oil pump drive gears and fractures the plastic idler gear.
  3. Trash gets in the oil pump, binds up the rotors, and the plastic gear fractures.

Did you remove, dissemble the oil pump, inspect it and the oil pump cavity in the case? If not you should..

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Yes i checked the caps, and look  to have got away lightly, hard to believe but no noticeable wear,  but time will tell.

I didn't remove the oil pump, but rotated it , and it now pumps fine.

I will run it for 100 km,then drain the oil and see what it looks like.

I will keep an eye on the dipstick hole, as its quite clear when the oil pump is pumping.

I bought the bike used, so who knows whats happened in the past.

Thanks for the reply.




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