high pitch tapping sound R cyl. & light backfiring -

[Nicolai]

Greetings from a newbie to this forum (and to Stelvio 2013 - but former Le Mans racer in 70's France);
I've put 2500 miles on my Stelvio (20K now) and TWICE adjusted the valve clearance (0,10mm=0.0039 IN / 0.15mm=0.0059" EXH) as per shop manual. Result is a noise (not unlike tappets) on Right Cylinder but ONLY when HOT and <2000RPM and there is some backfiring now that was not before. I have not done the TPS adjustment, which could be contributing factor to the backfiring - but then again, there was no backfiring before I adjusted the valve clearances.
I tend to be a worry wart and since the bike is my present (to self) for surviving first cancer surgery, the second present being that I'd like to head x-country with it, I figured I'd ask if anyone has input on the matter.
Thanks folks, ride safe and free!

 

[Android]

sounds like you have the exhaust valve just a bit too tight .....are you sure you had it at top dead centre on compression stroke relevant for that cylinder when you adjusted them.

sorry to say .......could be valve hitting piston re tapping noise

 

[john zibell]

Could be cam movement in the rocker box. Earlier bikes required shimming if I remember correctly, the new ones shouldn't. That is a possibility to be checked. It could also be from a rocker shaft as well.

 

[Trout]

You may want to make sure it is a 2013 & not a 2012.
The earlier bikes had flat tappets that fail.
The bike may be titled as a 2013 but built in 2012.
If it is a flat tappet bike you will need to have it upgraded quickly before damage is done.

The only way to know for sure is to pull the cam box & look.

In the search box put in flat tappet & you should be able to find a "How To" to do it.

 

[scott_m]

Oh dear god... First off, your cylinder is not hitting your exhaust. If it did, the force would send the valve bashing back up through the head. Forget that nonsense. Next, you SHOULD hear some sound in the valve train. If it is quiet, you have it way too tight. Third, the TPS has absolutely nothing to do with the valve train. What it does do is fully explained in my post here:

https://www.guzzitech.com/forums/threads/syncing-throttle-bodies-stelvio-8v.9082/

Also, if you listen some of the people here, they will have you convinced that your bike is a ticking time bomb just waiting to explode unless you immediately change out the valve train. This is simply not true. Many Stelvio riders, myself included, have experienced no engine trouble whatsoever, nor have my valves moved from their settings, nor have the cam face DLC (Diamond Like Coatings) been damaged in any way. Then again, my bike has been serviced according to Moto Guzzi's stipulations TO THE LETTER. No oils other than the proper AGIP (now Eni) have ever been in any part of my engine and no oil filters but the factory recommended. My engine works perfect and so does my transmission.

Now, you did not stipulate the level (intensity)nor frequency of your "backfire" so this makes it virtually impossible to diagnose a possible cause. I will tell you that with the factory stock exhaust, and therefore, every single aftermarket exhaust as well, the motorcycle is set to run very lean in order to meet worldwide emissions standards and if you really listen carefully, you will hear popping in the stock exhaust canister, although it is greatly dampened with the internal diverters. A straight through aftermarket pipe, sounds even more because the sound waves are not dampened.

In order to accurately advise you about your "backfiring", please give a better description. Intensity, Interval, conditions where this happens, etc. Then I can offer more advice.

It could be something as simple as you buying gas from a different supplies than normal (formulas vary), or a different octane rating fuel. Bottom line, in order to make an informed guess as to the cause, it requires more information from you.

Best wishes!

 

[Lannis]

Also, if you listen some of the people here, they will have you convinced that your bike is a ticking time bomb just waiting to explode unless you immediately change out the valve train. This is simply not true. Many Stelvio riders, myself included, have experienced no engine trouble whatsoever, nor have my valves moved from their settings, nor have the cam face DLC (Diamond Like Coatings) been damaged in any way.

Any names or aliases (if names are inappropriate) to go along with the "Many Stelvio Riders" data?

I CAN give you the names of "many" 8V Guzzi (including Stelvio) riders who have had their valve trains fail due to the DLC damage problem; I can give you one (Me) who had the shop take his valve train down at 40K miles (on a bike which has been serviced religiously, treated well, and only used the recommended AGIP lubricants) and found the DLC faces badly discolored and on the point of failure.

"Ride Until Failure" seems like an expensive sort of way to go, since destroying the cam followers while running could lead to complete engine failure.

I don't know anyone (yet) who has the mileage I have on mine that hasn't had the valve train fixed .... ? So I really don't think it's just hysteria.

Lannis

 

[scott_m]

Any names or aliases (if names are inappropriate) to go along with the "Many Stelvio Riders" data?

I CAN give you the names of "many" 8V Guzzi (including Stelvio) riders who have had their valve trains fail due to the DLC damage problem; I can give you one (Me) who had the shop take his valve train down at 40K miles (on a bike which has been serviced religiously, treated well, and only used the recommended AGIP lubricants) and found the DLC faces badly discolored and on the point of failure.

"Ride Until Failure" seems like an expensive sort of way to go, since destroying the cam followers while running could lead to complete engine failure.

I don't know anyone (yet) who has the mileage I have on mine that hasn't had the valve train fixed .... ? So I really don't think it's just hysteria.

Lannis

Suffice it to say that I speak English, French, German, and Italian, and have friends that ride Stelvios worldwide and I belong to Stelvios clubs in other countries with boards in other languages.

Not every Stelvio has experienced nor will experience a problem, and in fact, I would bet that the majority have not. However, even you admit that when you tore down your bike at 40k miles, it was not destroyed, but "discolored on the point of failure". That is far from destroyed.

Oh well, I'm glad your happy now, well relatively speaking.

As to names...I'm sorry but they are my friends and very nice people, and it would be unkind of me to subject them to someone as aggressive and hostile as you,

Best wishes!

 

[canuck1969]

Hello, my name is Canuck1969, and my bike had flat tappets and gave me no problems.

Yes, I changed them out at 50,000km with no running issues and minimal damage (I hesitate to call it that). Yup, DLC was gone and I am sure swimming happily in my engine for many thousand KM's. Only reason I changed it is I had a dealer that was able to secure me a set of roller tappets at no charge to me. Installed them my self. Bike never gave me any issues and never made a sound. And contrary to what some people think, even Canadians may know a thing or two about servicing a motorcycle.

I have not heard of one "failure" that has actually destroyed a valve train. Have only heard of one supposed main bearing failure, but the connection to the DLC coating was sceptical at best.

Did my valve train blow up...no....ran like a champ right up until I replaced it.
Did my main bearing blow up...no....and still running strong
Did my oil turn into pudding and my exhaust spit pudding pops out its hole....no....but that would have been cool.......

Will every flat tappet fails eventually.....maybe........but not every noise coming out of an flat tappet engine is caused by this. I had a friends Stelvio with 60,000KM finally eat up his tappets and cams and he kept riding it for months until the parts came in. Bike is still running fine. That was a 2009 and had cam issues for other reasons.

People need to start looking at the simple solution to the problems, and not conjecture based on what happened to Billy Bobs Stelvio (I apologise if there are any Billy Bobs with Stelvios. At best, it just confuses people and causes undo stress.

To the original poster, if your tapping started after your valve adjustment, start there. Go back and retrace your steps. I am betting on you were not at TDC and then adjusted the valves. Remember, you need to be at each cylinders TDC independently. Others have also made that mistake so it can happen.

For the correct TDC, take the cylinder through its cycle. You will see the intake valves open and then once they start to close, you are approaching the correct TDC. Also, make sure the engine is stone cold when you do it. Even if you are off a little on TDC, it will make a big difference in your settings.

I attached a reference document on the procedure. (Scott, this procedure may have been your doing, don't remember now)

Good luck and let us know what you find.

 

[scott_m]

To the original poster, if your tapping started after your valve adjustment, start there. Go back and retrace your steps. I am betting on you were not at TDC and then adjusted the valves. Remember, you need to be at each cylinders TDC independently. Others have also made that mistake so it can happen.

For the correct TDC, take the cylinder through its cycle. You will see the intake valves open and then once they start to close, you are approaching the correct TDC. Also, make sure the engine is stone cold when you do it. Even if you are off a little on TDC, it will make a big difference in your settings.

I attached a reference document on the procedure.

I have a secret tool I use for TDC. It's a long plastic Slurpee straw! Any extra long and thick plastic beverage straw will work. The kind kids use for those huge 64 and 128 oz type fountain drinks at the gas station mart.

As you rotate the crankshaft nut in the front of the engine and the piston is beginning to rise, place your plastic straw in the open spark plug hole and PRESTO, you can visually track the rise of the piston to TDC!

Now, I always confirm TDC with a visual inspection of the timing marks on the flywheel, but the straw works every time, is incapable of causing any damage, and is too long to accidentally fall into the cylinder.

JUST MAKE SURE YOU ARE USING THE EXTRA LONG SLURPEE DRINK STRAW AND NOT A NORMAL LITTLE STRAW!

https://goo.gl/images/RE1hnA


Also, I couldn't see the file Canuk1969 posted, the link won't work on my iMac, but I know it's in the top level directory, inside the Stelvio Forum, labeled:

Stelvio Reference Topics/Recalls

Best Wishes!

 

[AlanNZ]

.

Now, I always confirm TDC with a visual inspection of the timing marks on the flywheel, but the straw works every time, is incapable of causing any damage, and is too long to accidentally fall into the cylinder.

Best Wishes!

Marks on the flywheel? I wish. My Stelvio has no timing marks on the flywheel that I can find. So I have no choice but to use the straw tdc method.
Regards
Alan NZ

 

[john zibell]

Looking at the file canuck1969 posted the only thing I would comment on is this. I like to insert the spark plug in a piece of fuel line, and start the threads using the fuel line. I've seen too many bikes with crossed threads that weren't started by hand, but by using a socket. Pulling the head to have a good insert put in from the inside isn't fun.

 

[Lannis]

Suffice it to say that I speak English, French, German, and Italian, and have friends that ride Stelvios worldwide and I belong to Stelvios clubs in other countries with boards in other languages.

Man! I wish I were half as pretty as you ...

As to names...I'm sorry but they are my friends and very nice people, and it would be unkind of me to subject them to someone as aggressive and hostile as you,

Best wishes!

ME aggressive and hostile?? Folks have the impression that "Mastrocinque" means "What do YOU want damn you?" in Romanian or something. You've been leading with your chin on half the posts you make.

Glad I have your best wishes though, I'm sure it's sincerely meant.

Lannis

 

[john zibell]

The purpose of this thread is to help Nicolai out with an issue he is having. Not to trade barbs or inflate egos. Should this continue this thread will be locked. The only real looser will be Nicolai as he does need assistance.

As for flat tappet failures, I've seen a bike with low miles (less than 8K) have the tappets going bad and causing noticeable wear on the cams. It is always better to fix a problem before it becomes critical. There is a reason that Guzzi has been offering the cam modification kits.

 

[abbienormal]

Going back to the original question. When you adjusted the valves twice were they significantly looser each time or just a little loose? I always use larger feeler gauges till I know where the clearance was at before I adjust them so the next time I know if it is normal or excessive. I keep a Word document with a list of what I have done at what mileage and a table with the valve clearances before I adjusted them.
Do I foresee immediate failure if yours are flat? No, but I am a worry wart and a bit anal so my 4V (8V, whatever) 2012 Norge had the flat lifters. At 2,900 miles I changed them and a 12mm (1/2") center on one lifter on each side already had the DLC worn off. Minor pitting in the cams. Fortunately with the information on this site and my past experience working on bikes I did my own work and paid $1,000 for the kit.
As for the popping the first thing I would check is the exhaust stud nuts to see if they are torqued correctly as they have a tendency to loosen. Check all the other exhaust clamps while you are at it.
Somebody on here measured their tappets hot and they said they open instead of close. If this is true then it may be normal noise once hot. Mine ticked till I put in the rollers.

 

[Nicolai]

Grazie a tutti!
Stelvio is Nov. 2013. Where do you find whether A5 or other series? Mfr handbook gives wider clearance on EXH (+0.05mm) above A5.

Tapping noise: it came with the warmer weather. I adjusted spot-on to specs+0.002mm (feeler gauges I have). No improvement. It is ONLY on the RIGHT cyl. and ONLY when warm/hot under 2500rpm. A highly sophisticated tool consisting of a balsa chopstick was used for TDC. Since I'd had to straighten one turn of sparkplug thread (why in heavens are there these two large hollowed out bellows around the plug stem? They gather dust and grit) I used a plumbers scope to check for dust or marks on piston and it was clear.

Backfiring: is noticeably more frequent (every deceleration) since valve adjustment. It is regular and at low rpm, not the kind that I have (previous life) known to be associated with a burnt valve (which I seem to recall as much louder Bangs). I have stock exhaust which has some rattling, possibly a baffle? I received the bike with a leak at the Right side gasket into the Y exhaust collector and I'd replaced that before Spring and not noticed the backfiring after replacement. Ive never tuned an injected engine so not sure whether valve adjustment could cause such backfiring if TPS isn't also adjusted...

Maybe the only serious diagnosis is to ride off (..."into the dawn of Montana...with a pair of heavy duty zircon encrusted tweezers in my hand...").

Oh and another question (humbling): anyone have a technique to right the bike when fallen over? I lost balance on the kickstand and had to wait for a nice young man to offer help. I felt like Kaspar in Metamorphosis... I ain't small, but she is one big lady! I now carry a ratchet and 30ft of strap but I can't be sure I'll only keel over next to a lamppost or heavy duty cactus...

Fun and safe rides to all!

N

 

[abbienormal]

Grazie a tutti!
Maybe the only serious diagnosis is to ride off (..."into the dawn of Montana...with a pair of heavy duty zircon encrusted tweezers in my hand...").

Oh and another question (humbling): anyone have a technique to right the bike when fallen over? I lost balance on the kickstand and had to wait for a nice young man to offer help. I felt like Kaspar in Metamorphosis... I ain't small, but she is one big lady! I now carry a ratchet and 30ft of strap but I can't be sure I'll only keel over next to a lamppost or heavy duty cactus...
N

Ah yes, but the Stelvio is not exactly "The Pygmy Pony". If you do a look online there are several videos showing how to lift a fallen bike by backing up to it. It is easier than just lifting it. I do recommend taking off the riding jacket before lifting as the time I tried it, after my Norge laid down for a nap, my coat got caught on the bike and I had to lay it back down.

Your bike being a November 2013 should have roller lifters. Maybe the tick is not metallic? They are known to have the plug caps go bad. That could explain both problems. I am not familiar with how easy it is on a Stelvio but it is easy on a Norge. Possibly swap plug wires and see if it swaps sides. Or just put on a set of NGK plug caps anyway. There is a posting on here listing the correct ones to use. I did mine for peace of mind but I used high performance car wires and caps..

 

[Lannis]

The purpose of this thread is to help Nicolai out with an issue he is having. Not to trade barbs or inflate egos. Should this continue this thread will be locked. The only real looser will be Nicolai as he does need assistance.

As for flat tappet failures, I've seen a bike with low miles (less than 8K) have the tappets going bad and causing noticeable wear on the cams. It is always better to fix a problem before it becomes critical. There is a reason that Guzzi has been offering the cam modification kits.

Well, and that's certainly all true.

Prior to the roller conversion, my Stelvio (to borrow a roperism) sounded like "a washing machine full of crescent wrenches". There were a LOT of rattly metallic noises coming from it, especially from the left cylinder. However, in my experience, noises are only dangerous if they change, and these sounds didn't change for 40,000 miles of excellent riding.

Now that the roller conversion is in, it is much quieter - has a "sh-sh" sort of rolling sound rather than a "tap-tap" sort of metal impact sound.

I've dropped my Stelvio (either at a stop or <2 mph) twice, both times coming to a stop at gravelly intersections. Neither time could I even come close to picking it up - both times the person behind me stopped and helped it up, both times grunting "MAN this is a heavy bike - how do you even ride it?" Learning how to pick it up myself would involve several people helping to lay it over (or an overhead lift), some nice padded landing space, etc, and I've never gone to the trouble of doing it. Maybe I should.

Lannis

 

[GuzziMoto]

Maybe the only serious diagnosis is to ride off (..."into the dawn of Montana...with a pair of heavy duty zircon encrusted tweezers in my hand...").

N

I love the Zappa reference.
It sounds to me like your bike is a later roller bike, so all this "doom and gloom" talk about flat tappets really shouldn't apply.
If you pull a valve cover and look you can confirm that it is in deed rollers.
Valve clearance specs with Guzzi can be a bit varied, and sometimes the specs are more about noise then running right.

 

[john zibell]

I've dropped my Stelvio (either at a stop or <2 mph) twice, both times coming to a stop at gravelly intersections. Neither time could I even come close to picking it up - both times the person behind me stopped and helped it up, both times grunting "MAN this is a heavy bike - how do you even ride it?" Learning how to pick it up myself would involve several people helping to lay it over (or an overhead lift), some nice padded landing space, etc, and I've never gone to the trouble of doing it. Maybe I should.

Lannis

Unfortunately the new design team at Guzzi has raised the center of gravity on these bikes. It is much higher than on the Tonti framed bikes, they say for improved turn in. Even the 1100 Breva which I ride cannot be picked up alone. I tried it once using the back up technique (bag came off so she was completely flat on the right side) and suffered a compression fracture of L3 vertebrae. I had to have help to pick it up after the fracture.

Back to Nicolai's issue, the reference for exhaust leaks causing back firing or popping is good as is the mention of spark jumping for the tapping sound.

 

[scott_m]

Hey I'm sorry if I came off the wrong way. I certainly didn't mean to, but only wanted to offer a potential solution and alternative viewpoint on the issue at hand, not necessarily the definitive one. Public apologies, my bad.

I will say that some of the things I read though, are just plain wrong. One person, I thought it was here in this forum, actually said that valves will open up when they get hot! This is absolutely against the laws of physics and chemistry - specifically, expansion and contraction of matter.

To the original poster, YouTube.com has many videos under "how to pick up a heavy motorcycle". There are standard techniques demonstrated in the videos that you may find useful.