Topic: NASTY engine-noise (Sound file included)

[Terry in Australia]

Hi Terry I presume you have a split link in your cam chain then, otherwise it will be a struggle lifting the crank out.

Cheers

Den

G'Day Den, I won't be removing my crank (hopefully) as I only have to reseal my cases, and I don't have a soft link in the chain yet, but I bought a beaut chain breaker/riviter recently, so I'll buy a soft link for when I split the cases,just in case I need to. Cheers, Terry.

[MadDogMcq]

I'll be "internet-silent" over the weekend cos my kids have buggered-up my computer and I'd rather be in the garage fixing my bikes than fixing my PC, so hope y'all have a great weekend!!

[Terry in Australia]

I just had to come back inside, it's 100 deg F outside, and there are bush fires raging around Victoria at the moment, so I can't see the sun through the smoke, but geez I can feel it! Still, the 2K clear I sprayed my tank with last night should be as hard as glass by now! Cheers, Terry.

[mcpuffett]

nice and cool here in the uk this morning Terry , bit damp here and there with the odd tornado in london    ,   mick.

[MadDogMcq]

One here for the more "experienced" engine builders.....

I removed the oil pan (after undoing the exhaust to lower it down) and found tiny slivers of metal in the bottom of the pan. How much of this stuff would be considered "normal"?? After all, it's 30yrs old, has 30000 miles on the clock and there a load of gears crashing about in there - not just the engine bits.  I took a photo but can't upload it yet because of my broken PC. I've just nipped to work to post this message.

Anyway, that aside, I measured the distance between the top of the tensioner and the flange of the oil-pan and it was 69mm. I believe that is acceptable. The spring which applies the tension is about as strong as the spring in my pen! And boy, when you pull that tensioner away there is a scary amount of slack in the chains (scary to me anyhow).    Is this normal?

Speak again soon (when I've sorted my PC).

Tom.
 

[spitfire]

Hi Tom,
          Do you know any history on the engine, has it ever been apart ? Has it ever had a problem ? If so what you are seeing may have been flushed out after a rebuild. Or it could be part of an ongoing problem.
The cam chain could be a favourite for taking lumps out of the metal at some stage in the engines life, is it aluminium shards (get a magnet). Have you removed and checked your cam chain tensioner ? If the bikes been sitting it may be seized.

Cheers

Den

[Kevin400F]

This pic is from a CB500 engine I'm overhauling; bear in mind it has a Hy-Vo style primary chain with no tensioner.  It is an example of what sort of metal-chewing can take place when there's too much slack in the primary.  Yikes......the main oil gallery wall is about 75% chewed through!   I reckon I'll have a welder mate of mine dab on a little aluminum with his heli-arc rig before I reassemble this one.

Kevin

[750goes]

the red stuff looks like the sealing compound used for the gasket ??

there is also a few bigger pieces of metal there, that I would not really like to see if I took off my sump...

good flush out is called for, and a new oil filter and change a certainty....

[RRRToolSolutions]

The red gasket sealer is still evident around the sealing edge of the pan (shown in the 5 o'clock position in the pic), so I think that'sa good bet as a source for the red pieces.

This looks nasty to me - too much metal and the pieces are too large - something is wrong. We know from that before mentioned red sealer, that the pan has been off before. Those aren't wear particles, too big. That needs to come down for a closer look. The chain or something else is grinding away metal and it won't get better or find a good stopping place.

Regards,
Gordon

[MadDogMcq]

 

[spitfire]

HI TOM (SHOUTING),
                             Have a look at your cam chain tensioner, remove it and check that it is not siezed (3 bolts), then set the cam chain tension. Do this without running the engine, set the bike at 15o past TDC 1 & 4 cylinders (check the valves and piston position to ensure you are at TDC),  loosen the lock nut and bolt. The cam chain tensioner spring should then move the tensioner shaft to the right position. Retighten bolt and then locknut. Do not set the cam chain with the engine running !

Cheers

Den

[MadDogMcq]

Hi Den,
I'd already done that a couple of weeks ago. Someone pointed out that if you remove the tensioner, you can often see the amount of adjustment that has been made by observing the tightening-screw marks on the rod. So I took it out and looked.  It was free and working fine. I put it back and tensioned the camchain.

It's looking like the engine needs to be stripped right down no matter how much I hope to the contrary. I've spent a good bit of money on the 400/4 wheels, seat, gaskets, filter oil, polishing and respray, so I'm gonna have to slow things down for a while   I recently put rails and panniers on the BMW and that was £600, so her indoors is not very impressed at the moment. 

I guess the 750 will have to take a back seat until the 400/4 is finished. By then I will also have fitted a long worktop unit in the garage which will be very handy for the engine work. I'll put the oil-pan back in place, retighten the exhaust and ACF-50 the bike until New Year.

[spitfire]

OK Tom,
           Let me know if you want a hand, have tools will travel (only for free tea).

Cheers

Den

[MadDogMcq]

Thanks Den, it makes it so much easier to accept the engine's problems when you know you've got the assistance of someone else to call upon. Although I'm not happy to find that I have to strip the engine, I must admit that I'm quite looking forward to actually doing it and learning from it. I'll start to buy the various bits as and when I can afford to (no doubt David Silver reads these threads with great glee  ).

We'll let you know when Mick, so you can come and watch me cry as the crankcases are pryed open

Thanks again ppl. And have a great Christmas!!!

[supersport_CB400F]

Blimey, I had less junk in my sump and my piston rings had broken! I hope you have better luck with the 400 than you’ve had with your 750.

[Terry in Australia]

This looks nasty to me - too much metal and the pieces are too large - something is wrong. Those aren't wear particles, too big.

Regards,
Gordon

I agree, there's some big lumps of metal in there, and I don't know that it's all aluminium. Run a magnet over that #$%*e mate and see how much sticks, it could well be that some of that red sealant has blocked off one of the oilways in your head and your cam/cam towers/rockers have all been cooked, which would account for that nasty engine sound too. Don't despair though, it's fixable. Cheers, Terry.

[Hop on a Honda]

This looks nasty to me - too much metal and the pieces are too large - something is wrong. Those aren't wear particles, too big.

Regards,
Gordon

I agree, there's some big lumps of metal in there, and I don't know that it's all aluminium. Run a magnet over that #$%*e mate and see how much sticks, it could well be that some of that red sealant has blocked off one of the oilways in your head and your cam/cam towers/rockers have all been cooked, which would account for that nasty engine sound too. Don't despair though, it's fixable. Cheers, Terry.

Hate to agree with Terry, but it does sound like a blocked oil gallery to the head therefore the cam towers etc.
Ask me I have just been through the above whole senario, even the sump pix was similar.
Sin Loi.
Dave Australia.