Meaning of the markings visible throught the right hand side viewport?

[p6x]

I could see three cold stamped markings:

-There is an "S" which I believe stands for Sinistro or Sinistra for left in Italian; does it mean TDC Left Cylinder? should there be a "D"?

-there is another one with =- - which last indentation could be a 1

There is a third one which has been painted on and makes it unreadable.

I reviewed the workshop manuals but could not find any nomenclature on those.

Anybody knows?

[audiomick]

33 minutes ago, p6x said:

-There is an "S" which I believe stands for Sinistro or Sinistra for left in Italian

Yes, that is correct.

I did the valve clearances on mine recently, and found a mark for TDC for the left cylinder. I don't remember what it was, though.

I'm not quite sure, but I reckon I didn't find a mark for the right hand cylinder. Should be easy to check though: with the rocker covers off, watch what the valves are doing. Find the combustion TDC, go back a bit, and turn the motor slowly past the TDC whilst keeping an eye on the flywheel through the hole. That's how I found the mark for the left cylinder.

 

The most difficult part of the process was getting the cover off the alternator to be able to put a spanner on the front of the motor and turn it over in a controlled fashion. What a pain in the proverbial...

[docc]

I'll wait for Chuck to present this D-S translation in 'merican English .

Indeed the "S" is Italian for left.  And +1 on fussing with the alternator cover. Mine is made more complicated by aftermarket FIAMM horns (they are worth the trouble!). Also, be aware of the compromised strain relief of the alternator wiring that must be removed, and refitted, to the top of the cover. Stator failure, and problematic voltage spikes, can result from carelessness or neglect. Inspect your stator wiring and restore the strain relief any time the cover is off. Use a black "zip-tie" instead of the white. The carbon content makes them more durable.

I know to turn the motor in its normal rotation, clockwise looking from the front, and even scribed some arrows on the stator face as a reminder. The marking for the right cylinder ("D") is either 90º or 270º from the "S" and I can never remember which cylinder fires "first" and how far to the next. As in: If you find the "S", how far to rotate (clockwise) to the "D?" 90º or 270º?

The angle of view through the inspection hole to see these markings is not intuitive. A good light and a lift are quite helpful. Also, the crankshaft counterweights tend to spin the crankshaft suddenly during rotation and fly past the next mark. All of this rotation is best accomplished with the spark plugs removed to eliminate the effects of the compression.

While some might say the "D" is Italian for "Destro", I feel certain mySport's marking is "Destra" . . . 

[activpop]

Pulling the plugs is also helpful because you can use a straw to zero in on TDC proximity.

[p6x]

The point I was making is that I did not find a "D" mark.

Even with the "S" mark in the center of the view port, the exhaust rocker had no play. Since I am using the rear wheel to turn the engine, it is a hit and miss process.

Putting a dowel through the spark plug well does not work either, because the hole is not in phase. You can check the top of the piston can be visible with a flashlight.

I am thinking of doing it valve by valve. Get to the point where the rocker can be moved, and do that valve, repeat for the others. Even if I am not properly at TDC, it should work.

 

[p6x]

2 minutes ago, activpop said:

Pulling the plugs is also helpful because you can use a straw to zero in on TDC proximity.

Both the plugs are out. However, as I was saying in my previous post, the spark plug well is tangential on the V11. I tried with a wooden dowel, but it is not really as helpful as with a vertical well above the piston.

[docc]

44 minutes ago, p6x said:

The point I was making is that I did not find a "D" mark.

Even with the "S" mark in the center of the view port, the exhaust rocker had no play. Since I am using the rear wheel to turn the engine, it is a hit and miss process.

Putting a dowel through the spark plug well does not work either, because the hole is not in phase. You can check the top of the piston can be visible with a flashlight.

I am thinking of doing it valve by valve. Get to the point where the rocker can be moved, and do that valve, repeat for the others. Even if I am not properly at TDC, it should work.

 

I have never had any success with rolling the rear tire to locate TDC. Nor with the "straw" method. I do verify loose rockers, by hand, at TDC by cylinder.

Sure, maybe Sig. Luigi striking the "D" on your flywheel was on holiday when your flywheel passed the striking station.

Maybe it is just very hard to detect, by eye, through the inspection hole . . .

[80CX100]

Iirc doing the left cylinder first sets it up so that minimal turns will have the right cylinder in the correct tdc position shortly.

I use the tire rotation method (it can be a pita);have been known to cheat with a large old slot screw driver prying gently on the flywheel teeth.

I try to watch the valves moving through the tdc cycle, verify the correct tdc with a wooden skewer & that both valves are loose.

fwiw

[cowtownchemist]

I did my valves a month or so ago.  Mine did have both the S and D visible.  I used the tire rocking method as one of the bolts on my alternator cover appears to be stripped and I haven't had a chance to deal with that yet.  It took me a few tries with the tire to figure it out, but once you get the hang the rocking a little back, then forward it is pretty rhythmic to turn to where you want it.

[GuzziMoto]

I had no issues turning the motor by the rear tire, just use 5th or 6th gear with both sparkplugs out and it makes it very easy to turn (leverage is your friend). Using the rear tire also makes it easy to make sure you turn the motor the right direction (you don't want to turn the motor backwards for any of this). I also had no issues using a straw to feel for the piston. In fact, I have never used the markings on the flywheel for any of this. Not sure if the markings are even there. I don't like sticking solid objects down the sparkplug hole, I prefer things like straws that will give if things go sideways. A straw can't mess anything up.

[pete roper]

Thing is, since the adoption of crank/cam triggered timing sensors the marks are essentially completely irrelevant. You can establish top dead centre, or close enough to set valve lash, by observation or, if you've done it a few times, simply by *feel*. All that is required is the cam lobes be on the base circle while you are checking the clearances. What are the clearances for after all?

On bikes with points or a distributor of some sort you needed to know where TDC was and where the static and full advance marks were on the flywheel when you were strobing them but since the advent of electronic ignition and ECU's all that is unnecessary because all the needed data for engine management vis-a-vis spark and injection timing is controlled by a phase wheel behind the cam sprocket,(On V11's and the like.

Why the persisted on still marking the flywheels right up until the advent of the CARC bikes I have no idea? Force of habit probably!

Ignore any marks. They are utterly irrelevant!

[LowRyter]

the simple mnemonic joke... D = dis side  /  S = s'not dis side   (works for me).

Here's another hint.  Once you've found TDC, take a marker to alternator rotor.   Mark "D" at midnight, and the same mark will be for  "S" at 3 pm.   If the feeler gauge doesn't go in, it means your on exhaust stroke, you're 360 degrees off and you're at noon, rather than midnight. 

This is much easier than taking a flashlight and looking for those little letters each time.

[p6x]

15 hours ago, docc said:

I have never had any success with rolling the rear tire to locate TDC. Nor with the "straw" method. I do verify loose rockers, by hand, at TDC by cylinder.

Sure, maybe Sig. Luigi striking the "D" on your flywheel was on holiday when your flywheel passed the striking station.

Maybe it is just very hard to detect, by eye, through the inspection hole . . .

I did the left hand side.

At PMH (TDC), the "S" marking does not appear in the viewport. But the piston is clearly visible through the spark plug port, since it is tangential.

You are correct, moving the engine by rotating the wheel is not easy because there is very little movement required to jump the TDC when you are in sixth gear. It is a seek and trial to get it right.

And I can confirm I do not have a "D" that I can find on the side of the flywheel. Luigi went for a bathroom break and when he came back, the engine had moved to the next station.

 

[p6x]

5 hours ago, 80CX100 said:

Iirc doing the left cylinder first sets it up so that minimal turns will have the right cylinder in the correct tdc position shortly.

I use the tire rotation method (it can be a pita);have been known to cheat with a large old slot screw driver prying gently on the flywheel teeth.

I try to watch the valves moving through the tdc cycle, verify the correct tdc with a wooden skewer & that both valves are loose.

fwiw

I use a wooden dowel. You can find them at Michael's here in the USA.

But it is of limited vetting. You don't need it because the piston is right in front of the spark plug port. You can see it with a flash light. Actually, if you leave it inserted into the port, the piston may severe it, or at least damage it.

Now I obviously can't turn the wheel and check the spark plug port at the same time. So I just check when I have free play on both rockers.

Prying on the flywheel teeth would probably be the best way to fine tune it, if one was not afraid to damage the crankcase by using it as a lever for a screw driver.

[p6x]

4 hours ago, GuzziMoto said:

I had no issues turning the motor by the rear tire, just use 5th or 6th gear with both sparkplugs out and it makes it very easy to turn (leverage is your friend). Using the rear tire also makes it easy to make sure you turn the motor the right direction (you don't want to turn the motor backwards for any of this). I also had no issues using a straw to feel for the piston. In fact, I have never used the markings on the flywheel for any of this. Not sure if the markings are even there. I don't like sticking solid objects down the sparkplug hole, I prefer things like straws that will give if things go sideways. A straw can't mess anything up.

I do not think turning the engine one way or the other is detrimental to the operation. However, you need to make sure that whatever direction you were going, you did not go back and forth without catching on the mechanical play. This is very clear to me.

As far as I understand the "straw verification", if the spark plug was vertical in the same travel axis of the piston, you can clearly see the moment when the "Straw" has reached the TDC. With a V11, the straw can not be used in that way, because of the way the spark plug port is drilled with regards to the cylinder. Laterally. You just need to look through the port and make sure the piston is all the way up.

I agree a straw is safer than wood, although you could still severe a piece of the straw and needing to go fishing.

I just turn without anything in, and check it with my flash light.