During a recent oil change Istripped the oil pan bolt. It took a bit of trial and error for me to realize the stripped hole was a 14mm 1.25 thread so I got a tap and rethread it to 14mm 1.5 thread with a new bolt to match.

However, what I completely failed to think of at the time was all the metal I was cutting when rethreading the hole.

Since changing my oil the motorcycle has been running not to my satisfaction and my first thought is that I may have some metal shards swimming around in my oil wrecking havoc.

I'll be changing my oil again tomorrow hoping to clear out any contamination when I drain the oil but what should I do to best clear it out aside from tearing apart the whole engine which I may do at a later time but don't have the time to do now.

Should I run some oil through it and drain the oil multiple times hoping that the fluid washes out the contaminants? Maybe blast the oil pan with my air compressor to try to fish whatever I can through the plug hole?

Would this contamination really even be the cause of any major issues? I doubt it's much, a lot of the metal stuck tithe tap when I pulled it out, but how much did not.. I don't know, and didn't even think to check at the time.

2 Answers 2


Judging by your other questions on the site your motorcycle is a '12 Yamaha R6. If so, you have an oil filter, which should pick up the metal flakes and any other debris.

A new oil filter and fresh oil should be sufficient to clean out the unwanted debris.

It is unlikely that the metal flakes are responsible for a performance degradation if the oil filter is working as it should be. I would double check to make sure that the right amount of oil was put in the engine.


You could use oil flushing agent which is available from most motor factors or, if you cant get any, add a small amount of diesel to the old oil and allow the vehicle to idle for a short period prior to removing the old oil.

Also, a large magnet on the sump pan which you then draw to the drain hole should drag out any rogue metal trapped in the system.

I'm unsure if your vehicle has replaceable oil filtration but if it does, I'd be inclined to replace this during your oil change too.

  • 5
    While the magnet is a good idea, it'll work only if the metal flakes are iron or steel.
    – Zaid
    Commented Jul 10, 2015 at 9:42

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