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Taos3

Its alive. But afraid it is doomed.

8 posts in this topic

After sitting in my shop for three years I got the 99 YZ 400 running again. Tore it down greased everything real good. Rebuilt the carb, and put in a new plug. Bam, fired on the first kick. Started and ran on the third. Now I use to have a devil of a time starting this thing so I guess the carb, and plug had a lot to do with it. Took it to the track Saturday, and rode it all day. Ran strong, and had no trouble starting it all day. Got home, and drained the oil. &%$#@! oil had a silver tint to it. Bad, pulled the oil filter out, and even worse I had some small shavings in the filter. About enough to fit on the end of finger. not much, but bad I know. Drained oil and replaced with some new. Fired it up ran rough for a minute. Then it ideled out and ran great.

So where is the metal coming from? And what do you guys think I should do? Rebuild it now? Or ride again, and check for metal?

Thanks all

Richard Rowe

Ok- City

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Change the oil more frequently. That's pretty normal from what you read on this forum.

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Was the oil in the engine fresh oil, or had it been sitting for three years as well. I have a 99 as well. I bought it new. I get a little aluminum in the oil every time I change it. Do you still have the original clutch in it? If so, it could be from the plates. Also, is it metal or aluminum? I would bet on the aluminum. Ride it again and re check. I bet it lessens with time, especially if you are still using the aluminum clutch plates.

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Its probably just a bit of aluminum from your clutch. Mine has been doing that since new. Change your oil every 5-10 hours.

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It was the oil that had been sitting in it. I know I should have changed it, but it looked super clean. I forgot about the clutch plates. They are origional. I bet that was it. Thanks for the replies.

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I went through the same thing. Check to see if the metal sticks to a magnet. I had a pulsating sound when the throttle was cracked open in neutral. I solved my problem changing the crank big end bearing. Wala, no pulsating and no further metal in the oil. This is just a suggestion. Maybe it does not apply to your circumstance.

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Check for continued "silvering" of the oil. The odd chip or few isn't abnormal, but the presence of fine ground metal to the point that it makes the oil look metallic can be an indication of a bad bearing, whether it's the rod, crank, or whatever.

It may be that something rusted while in sat, which would be "fatal", at least for that part, if it was a bearing, especially. Rust, besides attacking the surface it forms on, is as abrasive as dirt. Not all oils are good at preventing it.

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Check for continued "silvering" of the oil. The odd chip or few isn't abnormal, but the presence of fine ground metal to the point that it makes the oil look metallic can be an indication of a bad bearing, whether it's the rod, crank, or whatever.

It may be that something rusted while in sat, which would be "fatal", at least for that part, if it was a bearing, especially. Rust, besides attacking the surface it forms on, is as abrasive as dirt. Not all oils are good at preventing it.

I have a feeling this may be the problem. It did sit for 3 years, and the chance it did not collect rust are slim to none. That was my first thought. I had a small amount of rust build up on one of the forks. I was able to get it off with a plastic sponge. Inside the motor is a different story. i think I will ride it again with the new oil and see what happens. The old oil did look metallic.

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