[IEATNOISE]

Greetings to all,
I'm new here so hopefully I'm posting this in the correct section..
I purchased a 1971 cb350 in pretty darn good condition about 6 months ago. It runs great, starts on first kick every time, and I have had no issues so far. I bought it from someone who seemed to take pretty good care of all his bikes, but i have noticed an issue with metal flakes in the centrifugal oil filter. At least some of the flakes are magnetic and its a fairly thick paste. I cleaned the filter and changed the oil then rode it for about 50 miles or so and checked the filter again, only to find the same issue. Does anyone have any advice on where to start for hunting this problem down.
thanks again,
Ave

 

[Frankjames]

Shift forks. ? Cam bearing are aluminum, non magnetic. Good question. 50 miles isn't many miles. It's either wearing fast or some metal didn't get flushed on the first change.

 

[83XLX]

Clutch material?

 

[screamingtiger]

What condition is the
Tensioner in?

 

[DD23]

If you take the clutch cover, Genny cover, valve covers and any other cover off you can gaing access to flush any crap from inside the engine out using a soft spray solvent.

Don't forget any oil troughs.

A magnetic sump plug is a good idea.

When you say magnetic flakes, can you post a picture.

Then fill with oil to correct level and use the bike.

The crap in the oil filter is usually a grey paste like substance with some "glitter"....

Gears, cam chain, rockers and bearings etc all wear, as does anything rubbing, sliding etc.

How good is clutch release and gear selection when cold ?

I presume it does not jump out if gear when riding...and the cam chain is not noisey, or valve working clearances at to spec...

 

[IEATNOISE]

If you take the clutch cover, Genny cover, valve covers and any other cover off you can gaing access to flush any crap from inside the engine out using a soft spray solvent.

Don't forget any oil troughs.

A magnetic sump plug is a good idea.

When you say magnetic flakes, can you post a picture.

Then fill with oil to correct level and use the bike.

The crap in the oil filter is usually a grey paste like substance with some "glitter"....

Gears, cam chain, rockers and bearings etc all wear, as does anything rubbing, sliding etc.

How good is clutch release and gear selection when cold ?

I presume it does not jump out if gear when riding...and the cam chain is not noisey, or valve working clearances at to spec...

Thanks all for the insight and I'll try and post some pictures this afternoon of what the sludge looks like. I never noticed any issues with clutch release or jumping gears when cold, but then again, I have not actually had much riding time with this bike in the cold.

One other thing i forgot to mention is since i've owned the bike the motor has made a subtle hollow sounding ticking sound that seems to be in line with the rpm. I have had older bikes before that make interesting sounds that ended up just being the normal operating sounds of the bike, but i dont have much experience with these 70's cb's.

I'll be tearing down the motor today to inspect the cam chain tensioner

 

[IEATNOISE]

This is what i found in the oil filter, a whooole lot of magnetic flakes
got the motor pulled out and I'm currently in the process of doing a tear down

 

[Frankjames]

That is a little more than normal. Open up the engine and you should be able to spot something.

 

[Frankjames]

Looks like possibly clutch but also looks like cam chain rollers that have worn thru to metal. Those are the first two places that I would check. Also the oil pump is most likely plugged, destroyed, or both. I would inspect it carefully. I'm not an expert but those are the areas that I would check first. Then probably the transmission.

 

[mrhonda1948]

The early camshafts had issues with pitting and breaking up on the lobes, which is probably what you are seeing. Amazing that it is getting past the oil pump screen and into the filter.