What is this irritating sound!?

So after getting the factory break in service roughly a week and a half to two weeks after it started to run badly/pop a bit right out of the blue on a morning startup. now this awesome noise which was a dull tap now is like river dance on the right side. ANYONE know what the issue is. I rechecked the valve clearance and everything is ok .01 intake and .015 exhaust. The strange this is it is itermitten when riding. sometimes it goes away completly





[You must be registered and logged in to see this link.]

Jeez , sounds like roadworks

The Clearances you are looking for are .006" inches (.15mm) inlet and .008" inches (.20 mm) Exhaust
The settings you mentioned above make no sense to me, Way to big if inches = rattly noise , and way small if mm ?
Good Luck

^^^^^^^^^^^^^^^^^^^^^^^
What Ron said.

Grade247 wrote:

So after getting the factory break in service roughly a week and a half to two weeks after it started to run badly/pop a bit right out of the blue on a morning startup. now this awesome noise which was a dull tap now is like river dance on the right side. ANYONE know what the issue is. I rechecked the valve clearance and everything is ok .01 intake and .015 exhaust. The strange this is it is itermitten when riding. sometimes it goes away completly





[You must be registered and logged in to see this link.]

I think the clearances shown here at .01 and .015 are just an error on the decimal point placement for 4 and 6 thou.  ie  should be 0.1mm = 3.9 thou inch and 0.15mm = 5.9 thou inch.

My understanding is the clearances recommended by Pete Roper and others for the 8V engine are 6 and 8 thou (0.15mm inlet and 0.20mm exhaust )

Those valves sound way too loose. "A loud tappet is [not always] a happy tappet." I'm guessing you didn't have it at TDC when you adjusted the valves. There is a lot of confusing info out there about how to find TDC. Also, I've never had any trouble with it on any bike -- except on the 1200 8V motor for some reason. What worked for me is remembering that I'm looking for the top of the compression stroke, and then just watching the valves (and double-checking by grabbing the rockers and making sure they have free play). Intake valves open, keep spinning, they close, then slowly move the crank to the spot where the valves are all closed and you can feel the free play. It sounds like you've got 1/4" of free play, rather than .006" free play.

I watched a friend of mine do the same thing on his 1200GS. He was watching for some timing mark, and I was watching the valves. I told him it wasn't at TDC, he told me the BMW timing mark doesn't make mistakes, he made huge adjustments to the valves (that's a sign you're not at TDC -- big adjustments), and he had to truck his bike to the dealer when it wouldn't start. Guzzis, on the other hand, will sometimes start with seriously maladjusted valves.

Finally, at the first service I loosened my valves to the .006"/.008" or .15/.20mm specs suggested in various Guzzi forums, even though the sticker under my GRiSO's seat said .10/.15mm. I didn't like it, and re-adjusted the valves 1000 miles later to the factory spec of .10/.15mm. Makes for quieter valves and I like the power delivery better. On my wife's 750cc V7 I've consistently set the valves at .15/.20mm, and that's what her owner manual calls for. The owner manual on my GRiSO has no valve spec (!) -- it's on a sticker under the seat. I hope some part of this rambling helps!

IF it's maladjusted valves, the noise would get better as you ride and the engine heats up. Heat makes metal expand, closing up the clearance. (NOT ALWAYS, see below..I'd take Pete's word for anything to do with a Guzzi engine).

Siggy Javotnik wrote:

IF it's maladjusted valves, the noise would get better as you ride and the engine heats up. Heat makes metal expand, closing up the clearance.

Depends on the engine. On the 8V in roller tappet guise the clearances open up considerably as the engine warms up. The coefficient of expansion of the alloy camboxes seems to be considerably greater than that of the tappet assemblies. This is less noticeable with the flat tappet system, I won't hazard a guess as to why.

As for finding TDC? Turn the engine using the crank nut in a clockwise direction. Watch the inlet valves open and then close. You now know you're on the compression stroke so keep turning the crank slowly and use a drinking straw through the plug hole to detect the rise of the piston. You can get the piston to TDC within a few degrees which is perfectly accurate enough. The tappets have to be on the base circles of the cams, that's all. The way the cams are ground TDC compression is a useful spot where they both are.

I suggest your mate learn a little bit about four stroke poppet valve engine operation before he starts farting about with his engine.

As for the 8V Guzzi? The factory changed the clearance spec, although nothing else, around the time of the introduction of the A8 motor. My guess is they theorised that the tappet failures might of been the result of the tappets riding the cam and opening up the gaps might help prevent this. Since it wasn't the issue it didn't. With a closed loop map it doesn't really matter if you set the clearances at four and six or six and eight. If you're running an open loop map it is critical you run them at whatever the map was built using.

Pete