Flat tappet failure pre-empting failure

I have a 2012 Stelvio - built in March 2012 however it is I believe fitted with mk 3 version of the flat tappet system, Larger oil ways feeding cylinder head cam area, higher output oil pump and lower profile camshaft (which produces lower HP 102hp and higher torque ) but still the flat tappet cam follower - Guzzi claim these mods make this later cam system wholly reliable. The mods they have made make a lot of sense and should certainly help the issue if not maybe even completely solve the problem.

Later that month rollers were fitted from i believe engine number 12596, my engine is 12536 so 60 units too early. Rollers are claimed to be used to reduce noise and not a cure for the Mk 3 flat tappet according to Guzzi technical department.

I am unaware of any failures of this latest cam system and can find no evidence anywhere of it failing.

But Guzzi in a way have me locked into main dealer servicing to maintain the warranty on the cam replacement if it does fail.

I have found a way to check the cams followers for failure far in advance of any major damage being done and its not expensive.

It may be of interest to anyone with concerns about this problem.

Millers oils from Yorkshire, (millers oils.co.uk) offer an oil analysis service which can detect abnormal particles of metals in the oil these would show up excessive wear of individual components by the metals they find in the oil at an almost microscopic level. They say they know what would be normal for most engines and can identify metals from camshafts, bearings, followers, pistons and barrels along with a host of other components as individual wear. once analysed the report outlines possible problem areas. If they are unable to id then a comparison test can be carried out after a period of time / mileage and that comparison would show up wear rate differences of particular metals in the oil ie alloy/ steel/ iron/case hardened metals etc.

The single test is £24 and the two part test £39.95.

I have no connection to Millers oils but think this may help put to rest worries for people concerned about premature wear on the Cams/ followers and also identify the failure long in advance of any engine damage being caused. How Moto Guzzi / Piaggio. might react to the test I am not sure but I do think it would give very good grounds for a warranty case in advance of a lot of noise from the engine.

Regards Jake.

My 2010 stelvio NTX had the original cams fail at approximately 8000 miles in late 2011, they were replaced with the later mark 3 cams under warranty along with the tappets, Guzzi refused to replace the oil pump stating that the later design of cams had solved the problem, these cams lasted a further 12000 miles when again they failed at approximately 21000 miles the entire cam assembly was then replaced with the roller design. The total mileage is now 32000 miles and is showing no signs of wear. my bike was up to having the roller cam assembly fitted fully dealer serviced in accordance with Moto Guzzi’s recommendations . As you say you have the higher output oil pump and increased size of oil ways so hopefully you will not have the problem however a friend of mine had a late pre- roller Stelvio and covered a lot of miles on it and had the cams fail at at I think about 40000 miles, so I suspect that all the flat tappet cams will fail I would recommend using a 10/60 oil with ZDDP or a ZDDP additive which helps to prevent metal to metal contact on high load components such as cam lobs on flat tappets. I found it interesting when my replacement roller cam kit was fitted to be told by the mechanic that it was the same design as used in the Californian 1400 but that the parts had been slightly modified to fit in the 1200 motor.I hope you don’t have any problems and think you are taking sensible measures to detect any early signs of cam wear
regards Keith

Thanks Keith its interesting what you say, according to Moto Guzzi, the other changes make the difference from the earlier models being retro fitted ie the lower cam lobes (produces slightly lower power 102hp but better low down torque) the bigger oil ways and the high output oil pump so maybe not the case going by your mates experience.
Moto Guzzi say not except where wrong grade oil has been used.
My bike has full service history and has always had 10W60 oil used. Guzzi have informed me they have warrantied the tappet area in any case .

Also the shop I bought it from (Youles in Manchester) Piaggio agent but not Moto Guzzi - have there own owners lifetime warranty ! so they say so if i get the bike serviced there which ties me into servicing down south all engine gearbox and transmission bits are covered for the time I have the bike. (probably a long time I’m thinking).

I would rather do my own servicing but at the moment will go with either Youles or Moto Guzzi locally.

Youles were authorised to service this bike by Piaggio (I even spoke with Piaggio regarding this before buying to ensure the warranty by Guzzi would be upheld), Youles had to follow their service schedule exactly, so did remove the sump clean the gauze filter during the service etc, and it was filled with Sachs Silkolene 10w 60 oil, they even gave me the remains of the second 4 litre container of Silkolene.

Have to say Love the bike, really got lots of character for a modern bike. It fits me far better than my old Spada that was for me too small and i have been struggling to find a Guzzi that suited my needs but seem to have done so now.

I will do the oil checks at the start and end of a year and at least can monitor for changes in what they find in the oil. Hopefully none.

Cheers Jake.

My 2012 Stelvio 8v is engine no. 12523 - would that be the same as your version?
10w-60 oil and dealer service but dealers in this part of country are few and far between!
Only covered about 10,000 miles so far with no problems but may consider oil test.
Should have stuck with my Breva 1100!
Keep us posted if any further feedback
Enjoy the summer!

HI - Like wise my bike only has 10500 miles - It looks like your maybe in the same boat as me probably with the flat tappet system in your engine ( but again you never know with Guzzi - depends what came to hand on the day when Louigi or Mario was putting your bike together). Moto Guzzi and Piaggio only say they can’t be sure as some engine builds had rollers fitted prior to the records being kept from number 12596 but they think my bike has possibly got flat tappets but they are not sure.
Exact records are not available it appears, The previous owner was told by Guzzi it had rollers i am told not. ! Its a bit frustrating.

So I have had a look mine are the flat tappet followers

The oil tests on my bike came back yesterday all was fine well almost - no trace of abnormal levels of metals or anything else worrying - except high moisture in the oil which is not good and the bike had a full sump off oil clean and change only a month ago. And the mileage since the oil change is only a bit under 500 miles (the reason i will repeat the test at 5500 miles on the oil).

This moisture shows the bike hasn’t been getting hot enough the last few rides which were reasonable length rides in miles, but in very cold weather 0 degrees to +3 degrees - so as i have read elsewhere the oil cooler is so big it stops the engine getting up to temperature in colder climates - there is not a thermostat system to by pass the cooler, so maybe I need a partial cover to help get the engine hotter this would help get the oil over 80 degrees and boil out the moisture in the oil. A real pain really when a thermostat would really have saved any problems on this cooling system - But as the Oil goes from sump to oil pump, through radiator and direct to heads in large volumes one needs to be very careful about altering the oil flow in any way.

The oil test also showed the oil had very high levels of Boron - which is a very good thing as this is an extreme pressure additive that acts like a cushion between contact surfaces. I intend to do a follow up check just before the next oil change and thereafter probably once a year @£24 per test it lets me know whats going on deep inside the engine without the worry of a strip down.

just for the record my bike has been serviced using 10 / 60 Fuchs silkolene extreme performance fully synthetic ester motor oil.

Ta for the interest Hope my comments help. Jake.

rallyejake…Have a look on google images. Just type in…Moto Guzzi Stelvio roller tappets…plenty of images to show you exactly what to look for.

I might be wrong but I seem to remember that the cylinders are partially oil cooled, as well as air cooled (by the exterior finning),and so that’s what the oil cooler does. You could cover it but then what happens if you’re stuck in traffic all of a sudden or the weather suddenly changes.

Re the tappets I’d be happier looking at them rather than trying to find traces of bits of them in the oil.

Just IMO…

I have never been stuck in traffic on a motorcycle :confused:

But then you don’t have a shed bolted on the side of yours.

Some years back I was filtering past an accident scene and the Rozzer directing things pulled me in to the side across a lake of spilled diesel. Wanted to know if I was in the habit of passing traffic in such circumstances. ‘Yes – I always filter past blockages, it’s one of the reasons I ride’. So he held me there for a while because he could before letting me ride back through the diesel. So I then had a few cautious miles scrubbing it all off. There’s safe then. Idiot.

Not ridden in Brussels then?


Jim, I have ridden Brussels, but getting stuck in traffic is something that I have managed to avoid.

I think you misunderstand me, The oil cooler is very effective at cooling the oil and as such the exhaust ports and cylinders etc in very hot climates thus the reason its so big, however in very cold climates or wet climates the cooling system is too efficient and the engine struggles to get upto temperature so the oil runs cooler about 70 degrees max, 80 degrees is the minimum temperature it should be working at. So by partially covering the radiator and keeping an eye on the oil temperature gauge i can ensure the oil is running at an average but optimum temperature, ie 80 to 100 degrees (although fully synthetic is ok to much higher temps.

As regards to keeping an eye on the flat tappets, it involves a barrels off rebuild to get them out to check them and the damage can not be seen by a naked eye you need a microscope in the first instance until its way too late and you have massive chunks of case diamond hardened steel coating and or steel whizzing around your engine taking out bearings barrels etc.

The Oil sample system can detect 1 part per million which is so low it would cause no damage to anything. Any raise in parts per million would show a change in metal wear this would still be long before the parts were big enough to cause any damage at all.

If you wait till you here a lot of noise your probably way off the scale of the safe limits. And you could be looking at a complete engine rebuild.

Ive added a scale in a later comment regarding the oil analysis system of whats safe and what is not.

Cheers jake.

OIL analysis - maybe this is the boring stuff

It’s like getting your blood tested at the doctors the analyst can see changes or unusually high or low readings that point to certain problems long before they become symptomatic.

The limits for various chemicals in the oil are measured in PPM (parts per million) parts of 10 microns can be measured. 1000 PPM is equal to 0.1 % of the oil qty. So small measurable amounts of contaminants point to various mechanical failure of metal parts

Ie Nickel (Ni) would point to Valve plating steel alloy from Crankshaft or Camshaft, Iron (FE) could point to cylinder liners, rings, gears crankshaft oil pump gear gudgeon pins, Chrome (Cr) again rings, Liners exhaust valves shaft plating etc

The acceptable limits for a petrol engine are given as PPM for some of these metas are Chrome 40ppm, Nickel 15ppm, Tin 40ppm, Iron 300ppm, aluminium 40ppm. copper 75 ppm. and so on.

combinations of raised elements point very much to specific wear areas.

The analysis can also find additives etc to see what is doing a job within the engine Ie Boron is used as a cushion type effect it can not be compressed so stops metal to metal contact (Excellent in the area of Flat cam tappets and camshaft)

Out of interest the readings ppm on my oil show the following at the moment : chrome zero, lead zero, nickel 1, tin zero, boron 241,iron 2, silicone 4, vanadium zero, aluminium 1, copper 15, sodium 10.

copper boron and sodium are all additives in the oil.

Still its not everyones cup of tea but thought i would point out the system to those who might be interested. It could save your engine from a lot of damage.

Cheers jake.

Steveh cheers for the comment - i have identified mine as flat tappets and am aware of the pictures and horror stories, But like i say earlier - to actually get to the flat tappet to check them is a major undertaking, barrels off job, as you need to loosen the cam box which is part of the cylinder head bolt set up. so new base and cylinder head gasket , exhaust gaskets lots of disturbing the engine - as well as re-setting the cam chain timing, the wear might not be visible after all that bother even if its started you can’t see it till its to late and the expense of that strip down too much hassle and detrimental to the engine.

I’m happy to ride my bike and use it as much as i want - i just see this test as similar to a blood test at the doctors - lets you see whats happening at regular intervals for not a lot of money.

Long before symptoms or damage occurs - that could well be a lot more costly to repair if not noticed.

Cheers Jake.

I have now had a second oil test done at 13000 mile 3000 from the first test. (PPM = parts per million) ( bracket area shows sources)
This shows some differences in the metals and additives in the oil,

+1 PPM of lead (usually from main bearings area) N/A how much shows
+2 PPM of iron (usually from cylinder liners, rings, crankshaft, camshaft, valve train, oil pump gears, gudgeon pins) Safe upto 300 ppm.
+11 PPM Silicone (dirt, seals, and sealants plus lube additive) Safe up to 50 PPM
+1 aluminium (Pistons and main bearing area) Safe up to 40 PPM
+26 Copper, ( oil cooler lining tubes leach copper in to oil for first 20,000 to 30,000 miles, also main and rod bearings, bushes etc) safe upto 75 PPM
(Copper content should decrease in time as engine beds in and more oil changes are carried out).
drops in content
Sodium -5 PPM (Salt in air over winter)
Molybdenum - 1 PPM ( probably due to breakdown of additive in the oil)
Boron -116 PPM ( this is due to the boron attaching itself to metal parts as a protective layer so no longer carried in oil - doing its job like Zinc)

The test shows no wear of any concern on the flat tappet cam followers or camshafts.

Now I have a base set of figures and no significant wear on the engine or valve train - I will carry out further tests every 6000 miles to keep ahead of the game so can moniter should any wear start to show up.

Cheers Jake.

Thanks for keeping us updated, Jake.

As an owner of a flat-tappet Stelvio, I was tempted to take out the cams and followers at the last service to check the condition but I ran out of time. I have the intention of swapping over to rollers someday (pre-emptively and at my expense) but I keep thinking of the many examples of the 1200s running flat tappets worldwide with no such problems. Hence…I do sleep easy at night!


I had my cams and followers changed by Twiggers last month, before they started to self destruct. As the bike has a full service history since new, Piaggio supplied the parts, and I paid for the labour and consumables. I am very happy with the outcome, the engine is quieter and seems smoother. I am not sure if the cam profile is different but the change seems to improve the bike’s performance, maybe it is because I’m not worrying about it any more and don’t get a horrible knocking on acceleration from low revs like I used to especially if cold, that used to make me back off the throttle.

Chris - Did you get a look at the stuff they took out?

No, I should have done but I was in a hurry to get back to Essex :unamused:

I got paranoid and replaced mine, its quite easy to whip the LHS head off and have a look; which also lulls you into thinking the whole job wil be easy in as nuch you can leave the air box in place. not so for the RHS but still a quite nice job.

I thought I could hear a change in the noise the tappets were making, but the clearances were not changing. I’m a lot happier now plus the engine charactor has changed with the roller map installed and goes like a greased weasel.

I have pictures of the kit and the tappets if anyone wants to be bored :slight_smile: