[ZiggyZipgun]

Back in...2001 I bought a rather decent CB350, looked like it'd been sitting in the back of a garage for twenty years. Around the same time, I bought a CB500T that looked like it had been laying in a field for ten years (it actually had been), and I blew the rest of the nice weather that year trying to polish a turd. I ended up selling the 350 to a good friend, who shortly thereafter sold it to a friend of his, only to buy it back a year later, and now, several more years later, sell it back to me. He rode it for most of 2007, replaced a few parts, fixed some wiring issues, etc. The few times that I'd taken it for a spin while he had it, it ran very well. So this year I decided to buy it back, and he quickly went over necessities: "New brakes, new tires, new battery, new points, new oil....oh, and last time I changed the oil, there were metal shavings in it, like, in the oil. So you may wanna take the head off."

Now, I'm not a mechanic by any stretch of the imagination, but I can tune these things and keep them running well. However, I've never had to open one up. With this vague description of the visible symptoms, what would be your (the forum as a whole) instinctual diagnosis, and immediate course of action? Also, what manual is better for this? I have a Clymer on the way, it should be here by Monday, and I just bought an Allen screw kit and a gasket set, since I'm obviously going to need them at some point.

 

[dlslick]

Hard to say what those "metal" chips could have been. What kind of metal were they? If it were mine I would get it running correctly without taking it apart and if it didnt make any wierd noises ride and enjoy it.
IMHO
Don

 

[ZiggyZipgun]

...ride and enjoy it.

So the chances of it abruptly kicking the bucket are low? I've seen a few old threads where they talk about it, and most people seem to automatically begin a rebuild. Just now I found a good reply to one of those older threads:

"Steel filings could be removed with a magnetic drain plug, but alloy filings from the cylinders are going to continue to circulate around until they get trapped in the filter. They are not a good thing to get into the ball/roller bearings of the crankshaft, etc. Depends on how small the particles are to a certain degree." - Bill Silver, author of 5 books on Honda repairs and collecting, rated "Best of the Best" across the board on AllExperts.com.

Now my question is, since MagneticDrainPlugs.com only sells one for a '71 CB750, is it the same size as my CB350?

 

[NathanMT01]

It depends on what "kind" of metal shavings you have in the oil. I know that sounds funny, but it's true. I bought a 1971 CB450 and had metal shavings as soon as I got home. The drain plug was packed with them (didn't need a magnetic drain plug, the factory one is huge, and has a collection hole). I immediately took off the oil filter access cover, removed that assembly, and there was even more. But, there's something very important...

Although all the little bits and pieces of metal were in fact metal, it was clear that they were more "metallic" than real cold, hard steel. And the issue? There is a metallic coating on several (if not all) of the CB450 engine parts. They're just aluminum on the outside...the inside faces? Metallic coating. It had started to peel and ship in many places, such as the cam covers, the oil filter cover, etc. So it has been cleaned out, and although it's really not a lot of fun, the oil needs to be changed about 10 times as often. Only because I don't want any of those pieces clogging up any bearings, or destroying anything.

So as you see, it's quite dependent upon what "type" of metal shavings you have. Mine didn't hurt anything, and they won't as long as I keep an eye on them, and clean them out very often. The engine doesn't make any noise, runs fine, and that's that.



Moderators correction:
ALL the engine internals that are "metallic" are actually metal!
There are NO "metallic coatings" anywhere (with the possible exception of the "bronze" coating on some con-rods)! IF you have steel fragments, you have a serious problem...If you have aluminum alloy fragments, you STILL have a problem....
While the centrifugal filter gets a "metallic aluminum paste" built up in it during normal wear, this is a collection of miniscule aluminum particles.... IF you have any kind of metal "CHIPS" or "shavings"...Something is WRONG!.... Steve

 

[fasterspider]

My buddy Edgar who has been working on these little Hondas since the 70s told me that all that metal in the centrifugal filter was typical and nothing to worry about.
I think when I cleaned my filter, it had not been cleaned since the 70s. All that mung was scary looking.

 

[tbpmusic]

...ride and enjoy it.

Now my question is, since MagneticDrainPlugs.com only sells one for a '71 CB750, is it the same size as my CB350?

No, it's not the same plug.
The 175/200/350/450/500T all use the same plug, but not the Fours.

 

[ZiggyZipgun]

I haven't seen it firsthand yet. Having known him since I was a wee lad, my money says he was just surprised to see any amount of metal in the oil. I think his actual word was metal filings, which would be pretty fine. Nothing large enough to read MADE IN JAPAN on it. We shall see.

Thanks for chiming in guys!