Valve clearences and "cam-On" noise.

[Mr Clark]

Hi there,

Just picked up an 02 Monster S4 with 15k on it. It's had Services whenever it's needed it, but I plan on doing my own services on it so I know it's been done properly.

I notice you get a "cam-on" sound, as I've been told its called, where above 4k rpm you get a raspy sound from the engine / head.

Just wondering if this might be an indication that valve clearances need adjusting, or whether its just a characteristic of these engines?

Anyway, should be easier than on my GSXR400 as theres less cyls.

Cheers,
Rich.

[katana]

Oh this is bad. Monsters need engine rebuilds every 10 years so get a specialist to look at it as working on them is a kin to working on the human g nome structure.

Avoid Ducati metropolis and avoid Dave robinson.

[Mr Clark]

Oh, I should be ok then, I've just finished creating my own superhuman slaves, so hopefully servicing this Duke will only be slightly harder...

[katana]

I'd check the valve clearances and the belt clearance. Checking the cam pulley tightness and the tensioner bearings but hey what would I know.

[dunlop0_1]

My 748 does exactly the same @ 4-5000 revs. This is normal, if a ducati is ever normal.................?

[Mr Clark]

Thats good to know, either that or we both have problems!

Anyway, I've been reading about the ever so evil rocker wear problem, I plan on doing a valve check this weekend at the same time i redo my belts, but from what i gather, you need to take the cam's out to check the rockers for wear!

[dunlop0_1]

If you have stripped it down to do the belts and check the valves, taking the cams out is not that much more work although you do have to remove the opening rocker on the belt side first before the cam will come out. Get a manual though!

Neil.

[katana]

I meant belt tension

[Shauns4]

Hi there,


I notice you get a "cam-on" sound, as I've been told its called, where above 4k rpm you get a raspy sound from the engine / head.

Cheers,
Rich.

Nooo, the top end doesn't normally make much mech noise, only thing you should hear is the induction noise, the rasp you do get is with SPS cams fitted but at much higher rpm

[Mr Clark]

Hi,

well got the bike apart ok, far far easier to work on than Gixxer 400. So, got cams out, rockers etc, all closers are in perfect condition, and horizontal openers are okish. vertical rockers are a bit more work, but no flaking as yet, just starting to grey. I think they should be ok until I have enough money to get megacycle rockers in a few months time.

As a note, there was no chrome flakes in the oil, and in the pickup filter.

Now to clearances...

I have the following:

Horizontal: Inlet

Openers:
L: 0.17mm
R: 0.17mm

Closers:
L: 0.04mm
R: 0.04mm

Horizontal: Exhaust

Openers:
L: 0.23mm
R: 0.22mm

Closers:
L: 0.07mm
R: 0.08mm

Vertical: Inlet

Openers:
L: 0.17mm
R: 0.17mm

Closers:
L: 0.08mm
R: 0.09mm

Vertical: Exhaust

Openers:
L: 0.18mm
R: 0.18mm

Closers:
L: 0.09mm
R: 0.10mm


Now, there seems to be a lot of conflicting values out on the net. The original 916 values indicate that openers are good on the above (0.23mm on the limits) but the closers are too tight, as they should be around 0.10. Other values (Haynes, other "people" in the know) indicate that the openers should be a max of 0.15, and that the closers should be around 0.05 - 0.10

Well, theres loads of numbers being quated all around this, so it leaves a lot open to question.

I have a feeling that from taking a good guess from all of these quotes, 0.10 - 0.15 opener and 0.05 - 0.10 closers might be a good way to go.

Does anyone know what the S4 is supposed to run?

Anyway, thanks for looking.

[Sparky]

Here's the clearances from a German S4 2001 workshop manual if that helps.

[Mr Clark]

Thanks for your post,

I've got it all back together and running now, I thinkThe clearences and rockers may need doing very soon, in about 2000 miles, So I will get a shim kit between now and then. Also, will try and get some spare set of opener rockers to replace / send for replate when I replace the dodgey openers on this one.

Cheers

[katana]

America is your friend.