Gold in that thar oil!

Hi all,

I've just bought a 5 month old 07 450 EXC. It came with the motard wheel kit and the previous owner had ridden it (to work mainly) for 25 hours and 1,400 kilometers. I've ridden it off-road for three hours so it has a total of 28 on it now.

I changed the oil in the weekend and to my dismay found the oil in the drain pan was glittering gold! Very small pieces (1mm or less each) and lots of them. It appears to be a plating of some sort as it's gold on one side and silver on the other and does not stick to a magnet. As well as being in the pan they were stuck all over the bottom screen.

My local dealer here in Auckland, New Zealand thinks it's most likely to come from the cage on the big end (con-rod) bearing although there's no knock or any other unusual sounds coming out of it at this stage, and quoted around $2,000 (NZD) or $1,400 (USD) to strip and rebuild the engine. The 2K does include mains, rings and a few other bits that would be silly not to replace while it's all apart.

Does anybody have any thoughts on this? Is there anything else that's gold inside an 07 RFS engine? Anyone had this same problem at this early stage (or at any stage)?

To say I'm gutted at the thought of spending 2K this soon would be an understatement.

poor maintenance can hardly be said to be the bikes fault, i'd be questioning the previous owner if i were you, if your confident you know what your doing, i suggest you tear the engine down yourself and see what it looks like inside, at a guess i would say the oil filter has been left there to long and hasn't picked up these particles, so flush the engine with some cheap oil to get what's left of the gold looking crap out, then fill it up with some good quality 10-40 full synthetic (or whatever oil you prefer for over in kiwi land) and put a new oil filter on

chances are if it sounds right, it is right, but pull the cylinder off and have a look at all the bearings and seals anyway.

Fair enough, the maintenance is probably the culprit here. The guy presented the bike well and appeared fastidious. Judging by the amount of oil remaining in the 4L pack he'd certainly done several oil changes but the filters (especially the long one) looked a bit on the dark side...

So what did you find.....???? I bought an 07 525exc with 17 hours on it and motard set up as well. No stuff found in the oil when I changed it but I would be keen to know what you found.......

To me the real question is why did the guy sell it after only 5 monthes of riding? I'm at about 40 hours and haven't seen much of anything in the oil or filter at each change. I'm thinking it may have come apart and been repaired with some residual particles missed in the cleanout. I would change the oil again and run it some more to see if it gets worse(the particles) or begins to make noise.

run it till it starts to make a tick or clack.

if one starts shut it off right away and fix it!

hows the compression? I'd do like the others said... clean out the oil system good, and ride it... if it starts running bad, then worry about rebuilding.

not that they will do anything, but it might be worth telling the PO about your findings.

my 08 exc, had metal shavings in the trany filter for the first couple oil changes (under 10 hours) but nothing after that.

let us know if you find out where it's coming from and what you end up doing.

Hi all,

I've just bought a 5 month old 07 450 EXC. It came with the motard wheel kit and the previous owner had ridden it (to work mainly) for 25 hours and 1,400 kilometers. I've ridden it off-road for three hours so it has a total of 28 on it now.

I changed the oil in the weekend and to my dismay found the oil in the drain pan was glittering gold! Very small pieces (1mm or less each) and lots of them. It appears to be a plating of some sort as it's gold on one side and silver on the other and does not stick to a magnet. As well as being in the pan they were stuck all over the bottom screen.

My local dealer here in Auckland, New Zealand thinks it's most likely to come from the cage on the big end (con-rod) bearing although there's no knock or any other unusual sounds coming out of it at this stage, and quoted around $2,000 (NZD) or $1,400 (USD) to strip and rebuild the engine. The 2K does include mains, rings and a few other bits that would be silly not to replace while it's all apart.

Does anybody have any thoughts on this? Is there anything else that's gold inside an 07 RFS engine? Anyone had this same problem at this early stage (or at any stage)?

To say I'm gutted at the thought of spending 2K this soon would be an understatement.

If the PO rode it very hard on the street with the motard setup, this could have caused the issues with the plain bearings wearing out. When riding on the street, traction is very high. This can lead to premature failure of the plain bearings on the crank/conrod. Ideally, one would install a CUSH hub from an LC4 bike onto the rear wheel. This would absorb the 'hit' from the acceleration and preserve the plain bearings. Other option is to strip the engine and install 'roller bearings in the entire engine.

Good luck. Hopefully, the shavings are only from the break-in process and they will not re-appear after a few oil changes.

what d1k said if the po wasnt running a cush hub it could be bad crank bearings. from the sounds of it the amount of flakes in the oil sounds excessive?

I agree with the above with one correction, there are no "plain bearings" in the RFS (Plain bearings are used on the cam on the RC4, one end of the cam on the RF4). What we are delaing with is "Main" bearings.

The issue here is this, the main bearings used in the RFS engine are rollers, the inner bearing race has a shoulder on the crank side and the outter race has two shoulders to guide the rollers. When used in the dirt these engines where pretty happy. On pavment the combo of more traction and the power surges of a single and no cush hub the crank spreads. Approx 1/4 of the way thru the engines power stroke is the biggest load on the main bearings and at that point the mains pinch the roller and the roller stops rolling and slides! This make for big heat & breakdown of the oil layer between the roller and the bearing race. When we take them apart the inner race will have the hard surfacing worn thru.

All of the Motard, Dual sport/street or quad motors I work on I am converting to ball bearing mains (as KTM did on the XC4 engine). It is more complex than it appears as about 3/4 of a thousands of an inch needs to come off the crank so the bearings slip fit rather than press fit.

I will bet the rod bearing is fine.

I agree with the above with one correction, there are no "plain bearings" in the RFS (Plain bearings are used on the cam on the RC4, one end of the cam on the RF4). What we are delaing with is "Main" bearings.......

I stand corrected :thumbsup:

Well Dave now you got me worried. I am waiting on a set of non-cush 17" wheels from so-cal and am now thinking these are not good for my 08 450excr. How bad are they? Should I put a cush hub on them? I did read that someone thought the 08 had a dampened clutch basket but the parts book showed it to be a normal clutch. Can successfully ride them without hurting the trans? i do like pulling the front up a bunch and have been trying to stop it for fear of the wrong person spotting me. BUT it's VERY hard not to. Update: just changed oil(about the fourth time) at 1088 miles with 600 of that on road with knobbies. Engine side had one small speck of metal half the size of a pin head in filter, oil looked about like pepsi or a bit lighter with some very small gold about like pearl in paint in Pyrex bowl. Trans side looked almost new with some small black specks no metal at all.

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