Servicing the Stelvio ... and an end-float question ...

[Lannis]

So I've been going over the Stelvio (35,000 miles) to prep for the trip to the National and back.  Fluids were changed 2,000 miles ago so they're good.

Rear tire had 5000 miles on it, they generally go 6500 but I've seen too many guys say "Yeah, I think this tire will make the trip" and end up nursing it home with cords showing.   Too sporty for my blood, so a new Pilot Road 3 was levered on, and a couple of spokes sealed to stop a slow leak.   (I've ordered some new o-rings, nipples, and split rings from Harpers for next time.)

Ah, nothing like new tires to make a bike feel good.   You get to compensating for the flat strip in the middle and that's bad.

Noticed it had an April 2015 inspection sticker on it, so checked it over and the license plate light is burned out.   Three screws, out it comes, burned out for sure, and I'll try to match one up at the parts store this evening.   "What car is that for, sir?"   "A Moto Guzzi Stelvio motorcycle, 2009 model" " a WHUT? Who makes that?" etc etc.   5 watt 12 volt wheatear bulb, I'll have to find it myself I'm sure.

Valves haven't been adjusted since 22,000 miles, time for a look.   Take the plugs out, I remember that they are the originals, probably time to replace those too even though they're "long life" Expensive NGK "R" plugs.   I have two spares I bought when I bought the bike new .... 35K is probably long enough.   Carefully pull the spark plug caps off, I'm probably the only guy in the world still running the original plug caps on an '09.

Find TDC ... feeler gauges .... all 4 intakes are at .005" and need to be at a tight .004" (.10mm), so .001" recession since new.    All 4 exhausts are at .008" and need to be at a tight .006" (.15mm), so they've receded .002" since new.   That sounds OK, I'll keep an eye on it as time goes by.

Just for grins, I check the end-float on the rocker-arm carrier, and it's .010" each arm on one side and .011" on the other.   Anyone know what it should be, or if it matters?   There's no way to adjust it and the manual just says bolt it together, so I guess you get what you get ... I'll check it at each valve adjustment and see if it's changing.  No change is always good in an engine.

The old plugs are a lovely clean tan, but twiddle in the new plugs (I love the feel of that 3/4 turn of "crush" on a new plug gasket), slide the caps back on, button it up and starts up instantly, no stuttering or missing so I assume the old plug caps are still good.   I have the new ones in boxes and will probably chuck them in the toolbox and carry them around just in case, but I hate to mess with a good-running bike ....

Lannis

[Vasco DG]

How dare to trust it! It's going to melt into a pool of molten slag you know! Horrible, unreliable things...

[Lannis]

How dare to trust it! It's going to melt into a pool of molten slag you know! Horrible, unreliable things...

So I'm guessing the rocker float gives the characteristic little "clatter" until it warms up ... I'm going to assume (it's hard to use that word any more; curse you KevM!) that it's OK.

Got to give the guy at the chain parts store credit ... I showed him the burned out license plate bulb, he said "5 watt?"  I nodded, he reached behind him and handed me two bulbs.

It sure is nice working on a motorcycle where no one in the past has stripped out threads, put wrong fasteners on, pried sealing surfaces apart with a screwdriver .... etc.

Lannis

[Phang]

I measured the rocker end floats of my 2009 Griso SE when I did the first valve clearance adjustment at 643km (400 miles)

Here it goes:-

Cyl 1 IN - 0.23mm (0.009")
Cyl 1 EX - 0.25mm (0.010")

Cyl 2 IN - 0.25mm (0.010")
Cyl 2 EX - 0.27mm (0.011")

[Lannis]

I measured the rocker end floats of my 2009 Griso SE when I did the first valve clearance adjustment at 643km (400 miles)

Here it goes:-

Cyl 1 IN - 0.23mm (0.009")
Cyl 1 EX - 0.25mm (0.010")

Cyl 2 IN - 0.25mm (0.010")
Cyl 2 EX - 0.27mm (0.011")

That's almost exactly what mine are.   So I'll take that as a supporting data point, tell people that the clatter is a "feature", not a "bug", and ride in security.

Thanks!!

Lannis

[Phang]

That's almost exactly what mine are.   So I'll take that as a supporting data point, tell people that the clatter is a "feature", not a "bug", and ride in security.

Thanks!!

Lannis

For years I was waiting for the other guy who do such crazy things like me.

The reassurance is reciprocal, the measurements I made are meaningless until I see yours, give and take the ambient temperature and the fact that I am very near to the equator.

Phang

[leafman60]

Those m

[56Pan]

I don't believe that valve adjustment indicated valve seat recession.  That would have reduced the clearance.  Seems like normal valve train wear to me.

[Idontwantapickle]

How dare to trust it! It's going to melt into a pool of molten slag you know! Horrible, unreliable things...

I ran this through Google Translate set to Roper > English:

"You measured that? You need a hobby."

 

[Lannis]

I don't believe that valve adjustment indicated valve seat recession.  That would have reduced the clearance.  Seems like normal valve train wear to me.

I expect you're right; come to think of it ....

Lannis

[Lannis]

I ran this through Google Translate set to Roper > English:

"You measured that? You need a hobby."

 

Well, it LOOKS like some kind of clearance, and it SOUNDS like end-float which usually has a specification.   I mean, on anything else I've got that runs on a shaft or in bearings (BSA A65 crank, any layshaft, camshafts etc etc) that has a chance to wiggle, you measure it and shim it and make sure that it's in spec and not getting bigger so that things get out of line.

The fact that the service manual doesn't specify it should have given me a clue, and the "heap of molten slag" result, along with Phang measuring exactly the same thing, has put my hysterical, hand-wringing fears of a nuclear-level explosion of my cylinder heads to rest, and I can get back to worrying about the effect of the zinc content of my oil on my tappets, and which one of those things down there is really the "transmission" ....

Lannis

[Wayne Orwig]

So I'm guessing the rocker float gives the characteristic little "clatter" until it warms up ... I'm going to assume (it's hard to use that word any more; curse you KevM!) that it's OK.

I also understand that they made a change to one of the hydraulic cam chain adjusters, because it leaked down when it set. I'm thinking that may be the noise I hear at startup. And the cam or rocker float I hear like a cement mixer when it gets really hot.

[Vasco DG]

I also understand that they made a change to one of the hydraulic cam chain adjusters, because it leaked down when it set. I'm thinking that may be the noise I hear at startup. And the cam or rocker float I hear like a cement mixed when it gets really hot.

About 2013 I think the reservoir for the tensioners was en-biggened. I can't see it stopping them bleeding down but it probably means they'll pump up quicker. At 90,000km mine rattles for a few revolutions at start up but then quickly quietens down, it doesn't worry me, I know what it is. What does always concern me is the hellacious racket made by the cams whacking fore and aft at idle. Once the engine speed rises above about 2,500 rpm the nois vanishes but at idle when the engine is hot it's awful! Thing is it's done it since new and it never seems to get any worse, (Although I don't know how it could without blowing itself into a million pieces! ) so although it concerns me I've stopper actively 'Worrying' about it. Anyway, when I have a moment to scratch myself I'm rollerising my top end. That should shut it up!

I have to say I've never given the rockers a second thought.....

Pete