Camchain trouble?

[lars]

That is a SERIOUS Tick!

Maybe stupid question but how is your oil level and oil pressure?
For oil pressure remove the small bolt on the left side of the head before starting the engine. When it's out start your engine and there must be oil poring out within 1 min.

[Smithers]

That sound clip was brilliant .... Like Lars says "that's a serious tick" ......... it seems to be from the cam gear as it seems to be cycling at half crankshaft speed .....at first I thought it could be just one cam/valve making the noise but I'm not too sure about that now.......... is there a chance that the timng chain has slipped a tooth or two on a sprocket. For example if the inlet sprocket is slightly advanced the camgear gets noisy (I know because I advanced my inlet camshaft sprocket about half a tooth to try to get my settings closer to spec. and immediately the valve actuation got noisy)........ if that is the case inspect the tensioner to see if the fine teeth are all sharp...... did you retract the tensioner before installing it so that the camchain eneded up having the correct pre-tension? Check the camchain for any signs of damage as well...... inspect the cam surfaces for chips or premature wear, which implies oil starvation...... good luck

[zod]

Then I have done a day with some more research (and no riding ).
- Oil level and pressure ok.
- Cams still perfect.
- Valve clearances inside limits.
- Every sprocket/cog down by the oilpumps and the crankshaft-sprocket looks ok.
- Tensioner at click 11 of 17, mounted like it should.
- When I manually turn the crank the camchain from time to time makes a little kink on the chain between the camsprockets and then snaps straight again making a distinct noice.

As I said in my first post in this tread, I suspect the camchain has jumped a cog at the crankshaft when I adjusted the valve clerance. That could explain why my timing markings was a bit to good to be true...

My engine has done 30000 km

[Smithers]

Whew, that's all good news so far .... I feel daft asking this question, but here goes; did you replace the shroud that sits above the chain between the cam sprockets ..... I know, I know,.....who would forget to do that...... I nearly did!!! but it was late in the night and the wine bottle was nearly empty..... what is your cam timing like at present, is it the same as you showed on the previous pictures you posted?

[zod]

No questions is to daft when it comes to my mecanical abilities
Yes, I remembered the camchain guide.
I imagine the camchain snapping I get at 1 rpm (by hand), could get rather vicious at 1000++ rpms and be the source of the noice?

A new camchain is ordered!

[Smithers]

That's good insurance and your reasoniing makes sense......... it was interesting that your bike was running perfectly when you first started it up and then (after a few km's) it started to make the noise, that's why I wonder whether your timing is still the same now, as what was in your previous pictures ie. when you first started the bike up ..... Im wondering whether the timing changed .......the chain jumped a tooth ?

[andre]

That sounds horrible. After replacing my badly worn cylinder head last year, with a lower mileage second hand one.( It was eating through the journals on number 1 cylinder on the inlet cam.) I used aftermarket gaskets, when i rebiult it. Anyhow mine to started to sound very similar, but only once it had warmed up. Then i discovered oil in the header and water in the oil. And i think it was the oil in the water causing the noise, as the oil got hot it became to watery to lubricate properly. Put a new cylinder haed gasket in and so far so good. Fingers are still crossed that its not a cracked head or something. Only done about 100 miles since rebiuld. When i drained the oil it was like muddy water. Probably no help to you but that sound was just like mine.

[lars]

No questions is to daft when it comes to my mecanical abilities
Yes, I remembered the camchain guide.
I imagine the camchain snapping I get at 1 rpm (by hand), could get rather vicious at 1000++ rpms and be the source of the noice?

A new camchain is ordered!

Let's hope the new chain will fix the problems! But the funny thing is that you already knew the answer to the problem. Subject title!

[zod]

Yesterday I started the work on changing the cam chain:

[slow codger]

Its difficult to see from photo's alone but my guess is that it shouldn't make any difference re the balancing of the cam, as there will have been tolerances set in at the factory. the bolts I would think should be ok, but you need to see how much thread goes into the hole.
Oh and drain the oil and put new in to find the bits of metal.

Dave E

[Smithers]

Good piece of work .... I have to admit to considering the bolts being loose but thought " naaaah, never"........ dont be concerned with the torn thread on the left of the hole, that happens after a few times of being disassambled and being reassembled. The metal is hard therefore it tends to break off rather than deform .... cam shaft balance will not be an issue ......I use loctite to ensure that the bolts dont loosen, as a secondary measure, and make sure that the internal threads are clean and dry (no oil) and the bolt threads are the same brfore applying the Loctite. ..... pictures can be decieving but on the 4' oclock side of the threaded hole there is a stain which looks like a fracture ? .... I dont see why this area should have a crack, or is it just a piece of the top thread about to break away, in which case you could just probably break it off as it is not doing anything....... whew, glad you found that issue in time, top stuff.

[Mincehead]

Rule of thumb on bolts into tapped holes:

The minimum securing ability of a bolt through a threaded hole is roughly equivalent to the diameter of the thread.
I believe the cam sprocket retaining bolts are M6 (10 mm hex heads) therefore if you have 6mm of good thread in those cam flanges you should be ok.
If you`re in any way concerned use a little Loctite on the threads prior to reassembly.

[zod]

If you`re in any way concerned use a little Loctite on the threads prior to reassembly.

Loctite 243?

[Smithers]

Loctite 243 is perfect