• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

Any Ideas before I start digging???

Jeremy

CB750 Member
Messages
7
Reaction score
0
Points
1
Location
New Orleans Area
Hello, I was wondering if anyone could tell me what this piece of metal was I removed from my oil drain plug. I just bought this pretty decent looking 1974 cb750 from craigs list for $1000 and thought I was doing good until I got it home and noticed that at very low rpm it makes a clattering noise in the lower end. a friend of mine told me that it was the clutch carriage???? I will attach a picture of the piece I found stuck to the magnet on the plug. Any Ideas??? or should I start a rebuild....:banghead:
 

Attachments

  • metel.jpg
    metel.jpg
    207.4 KB · Views: 109
Last edited:
By the way here is the bike ..... and it runs so awesome....so much better than my cx.... im just afraid I will do damage to the engine if I ride it making this noise.... especially after I changed the oil and found the piece of metal..... thanks in advance for the advice...
Metal2.jpg
 

Attachments

  • Metal2.jpg
    Metal2.jpg
    260.1 KB · Views: 93
Last edited:
That kinda looks like a piece of a piston ring but not sure how it would break off and get away without some damage to the cylinder walls. Maybe it's a clutch part.
 
When I first saw it I thought the same thing( that it looked like a piece of a piston ring )but its about three times too thick.... I seriously doubt it to be part of a ring because the bike runs so well.... im thinking clutch part too but not to sure..... I still have the rattling noise on the lower left side of the engine too. hopefully its an easy fix what ever it is. Thanks for the reply...
 
Could very well be pieces left over from having a top end failure...unless someone just painted the cylinder, head and valve cover black that is not the original top end. It really does look like a piece of a ring. Many times if there was a failure in the topend that is all that is replaced and any parts that where not retrieved end up in the oil pan because only the topend was replaced. Only other part I can think of off hand is one of the transmission bearing to case aligning clips...they are a half circle piece used to align and hold the trans bearings in the cases.
 
well after thinking about if for a while I agree with you dirt digger...... looking at the diameter of the piece I found its got to be part of a ring and from a previous top end rebuild....that would explain why the cylinders are painted... looks like the magnet on the oil plug done its job.....:) Thanks
 
Clutch rattle would be on the right side. These motors are fairly noisy. The primary chains tend to get noisy and it could sound like clutch parts I guess. A noise in the left front would indicate a possible problem in the starter clutch, they can make noise if a spring breaks or if the clutch rollers are getting worn. Normally the only noises you get are primary chains, timing chain and valve noise. If the noise sounds like a rattle in the bottom end it is more than likely the primary chains.
 
It does it (rattle noise) in netural at low idle....almost sounds like when a starter doesnt disengauge.... when it warms up and starts idleing faster the noise almost goes away. thanks....
 
Back
Top