[Paul450]

Hey guys,

Recently I rebuilt my 2010 CRF 250R and did the crank bearings, gaskets piston etc.

The only reason I did the crank was because I never knew how many hours was on it and wanted to know what I had. The bike was running perfect before and after the rebuild and still is!

I did notice however that there is some very fine gold shavings in the oil after the new crank was put in. Not alot, about 5-6 tiny shavings which I can see if I take the oil pan into sunlight. The oil filter is clean, no shavings at all. The oil gets changed every second ride along with the filter.

I've stripped and rebuilt quite a few CRF's and I,m sure it is all been put back together correctly so I don't think anything is rubbing at all.

The bike was run in after the rebulid, first oil change had some shavings(again maybe only 6-8 tiny bits). Each oil change after that they started reducing. 3-4 oil changes later I have maybe 3-4 tiny shavings.

Is this something to worry about? I race MX and the bike is used very hard in the semi expert class.

Do you think I need to pull the motor again?

Thanks
Paul

[Paul450]

Just reading up more on this and to be honest I can not say for certain that the shavings are gold/brass. It could be the oil that is making them look like that. I need to take them out and let them dry off to confirm there exact colour.

I would also prefer to call them bits (very very small) rather than shavings as there is only a few, not lots like if you were to file down a bolt for example.

[JimDirt]

I am not going to say something can't fail , but if your not finding any in the filter , i would thoroughly , flush the motor (get some cheap oil that meets the engine requirements , because you are just using this oil for flushing purposes , so cost is the factor not quality) , and fill the motor to recommended specs , then run it long enough to warm it up and circulate the oil thru the motor , then drain it and look for shavings , if you find less then when you just changed it, then i would not worry about it , as it could have been leftover shavings from prior damage , but you just missed it somehow in your engine cleaning process during the rebuild (i dont know how thorough you clean your motors at rebuild , i tear mine completely apart and clean and flush every part and every nook and cranny with fresh solvent before any reassembly) , if you find the same amount or more , repeat the process , if you still find contaminates , then i would think about ripping it down and trying to locate the source

Your positive this is not clutch material from draining the tranny in the same pan , correct ??

[Paul450]

Thanks for the reply JimDirt,

Yeah its not from the tranny side. I use a different drain pan for that. I also use a new pan each time I drain the crank side to make sure the shavings s not from the previous oil change.

When I strip my motors I use a grease eater to flush out the casings. Basically a basin which pumps cleaning fluid out the end of a cleaning brush which I'm sure you've seen before. I then blast everything dry with an air line. The spray it all back down again with WD40 oil and then blast it again with the airline. So yeah I do take alot of care when putting it back together. I guess there is always a chance I missed something.

Your idea of flushing it out a few times with cheap oil sounds good. I'll give that a bash. I still need to confirm the actual colour of the shavings/bits too.

Thanks for the advice, I'll give you and update late.

Cheers
Paul

[JimDirt]

Yea , i use a Solvent Tank with a pump filled with Mineral Spirits , as i am pretty anal about things being clean

And yea some people will use the same pan for both without cleaning it in between and not notice the shavings until after they have drained both sides , and confuse clutch shavings for internal damage , so that was why the question , i use the same pan , but i flush the pan , then rinse , then wipe clean the pan before draining the other side , so i can see if there is anything in one side or the other , i also do the same when rebuilding my suspension , or when i am messing with the suspension valving , that way if there is any abnormal wear i will notice it in the fluid first , then do a investigation as to the origin of the shavings

And the flushing with the cheap oil will confirm your findings , or set you at ease , dont forget to run the engine enough to warm it and circulate the oil before draining

[Paul450]

Will do mate, cheers for your help! I'll keep you posted.

[JimDirt]

Yea , i have seen my share of engine shavings
(A friends 08 CRF250R before i rebuilt it)

[gmgearhead]

those are lower thrust washers and bushing material from lower rod bearing.They are made out of copper.

[JimDirt]

Correct ! , the pic was just to show I have seen my share of metal shavings in a engine