2009 V7 Classic – right cylinder knocking / lower compression

[xorti]

Hi all,

Looking for some advice before I pull the right head.

Bike: 2009 V7 Classic (EFI).

Symptoms

Started with:

• stalling when cold
• loss of power at higher revs
• one knock on first start, which then disappeared

Later developed a persistent metallic ticking/knocking from the right cylinder, strongest around the exhaust side.
Noise increases with RPM, slightly quieter when warm but never fully disappears.

Work already done

• Oil + filter change
• Valves adjusted multiple times (currently 0.10 intake / 0.14–0.20 exhaust)
• Updated timing chain tensioner installed
• Pushrods checked (straight)
• Rockers inspected – no abnormal wear or play
• Head nuts torqued 42 Nm (M10 studs)
• Exhaust gasket replaced
• Injectors swapped L ↔ R → no change

Endoscope inspection showed normal carbon and no piston damage, walls has crosscheck marks, no scoring .

Timing check

I also checked cam timing roughly by setting valve clearance to about 1 mm and rotating the engine to observe valve events.
The method wasn’t extremely precise, but left cylinder TDC aligns with the marks on the crank and nothing appeared obviously out of phase.

Other observations

• With exhaust removed I saw some oil mist near the exhaust valve stem on the right side
• Interestingly the left cylinder had more oil residue overall

Compression test

Cold engine, throttle open:

• Right cylinder: 9.6 bar
• Left cylinder: 11 bar

Other notes

• GuzziDiag previously showed right ignition coil error
• Plug-cap pull test: both cylinders contribute, though right seems weaker

Question

Given the persistent right-side noise + lower compression, does this point toward an exhaust valve / seat sealing issue on the right cylinder?

Before pulling the head, would you recommend:

• leak-down test? I do not have tools
• anything else to check first
• How common valve issues on 13k bike

So my guess is

• loose valve is rocking in the guide and making noice
• knocking when hitting the valve seat
• when the valve doesn’t seal perfectly, combustion gases leak past it and can create a sharp ticking sound that mimics mechanical noise
• timing jumped one teeth but still all two marks align

I’ll add a video of the noise.

Thanks for any input.
https://youtube.com/shorts/vqh4stjlxp4

https://youtu.be/CKkUQIhDwXk
https://youtu.be/dsWYpI2tt-E










[/list]

[Dirk_S]

You come across as knowledgeable enough about engine mechanics, but just to get it out of the way—you’re certain that you’re doing your valve lash adjustments at TDC-compression stroke for THAT particular cylinder?

Are both coils reading fine now?

[guzzisteve]

Get a leak down test performed, a shop won't charge much. Best to know where compression loss is going. May give you a clue to where noise is coming from. You could also put together an air hose fitting to a tool inserted in spark plug hole & listen to where air is coming from. Lock motor at TDC or take rockers out & test at BDC so motor doesn't turn.

[malik]

I would do the tappets again (0.10 & 0.15) followed by a throttle body balance (I use guzzidiag & a throttle lock to control the rpm at about 3,000rpm). This seems to even out all sorts of things, including reducing fuel consumption.

Also note that I had a persistent knock on one side - turned out to be failed spot welds fixing the inner header pipe to the outer. Mine failed at the muffler end, and the inner pipe would knock against the outer - couldn't positively identify the knocking source at the time. My local guzzi mechanic's usual fix was to drill a hole or 2 through the outer sleeve & do another spot weld. My solution was to replace the original header pipes with a set from Agostini - these are single walled & fatter. This eliminated the knock as well as seemingly allowing the engine to breathe freer. Just my suspicion. 230,000km now on the V7C, with no engine work, other than the tappets, done on the bike.

[xorti]

I would do the tappets again (0.10 & 0.15) followed by a throttle body balance (I use guzzidiag & a throttle lock to control the rpm at about 3,000rpm). This seems to even out all sorts of things, including reducing fuel consumption.

Also note that I had a persistent knock on one side - turned out to be failed spot welds fixing the inner header pipe to the outer. Mine failed at the muffler end, and the inner pipe would knock against the outer - couldn't positively identify the knocking source at the time. My local guzzi mechanic's usual fix was to drill a hole or 2 through the outer sleeve & do another spot weld. My solution was to replace the original header pipes with a set from Agostini - these are single walled & fatter. This eliminated the knock as well as seemingly allowing the engine to breathe freer. Just my suspicion. 230,000km now on the V7C, with no engine work, other than the tappets, done on the bike.

I did suspect the exhaust making noise and therefore changed the exhaust gasket, I will have another look

You come across as knowledgeable enough about engine mechanics, but just to get it out of the way—you’re certain that you’re doing your valve lash adjustments at TDC-compression stroke for THAT particular cylinder?

Are both coils reading fine now?

I would like to think I did, the one that had both valve closed, it is after intake valve closes

[Dirk_S]

I would like to think I did, the one that had both valve closed, it is after intake valve closes

Right. And each cylinder has its own TDC.; ie., you set TDC on the compression stroke (after intake valve closes) for one cylinder and check valve lash, then you set the TDC for the other cylinder and check its valve lash.

[xorti]

Right. And each cylinder has its own TDC.; ie., you set TDC on the compression stroke (after intake valve closes) for one cylinder and check valve lash, then you set the TDC for the other cylinder and check its valve lash.

Thanks Dirk_S, I am fully aware of it, the one I am interested in is after intake valve closes, on compression stroke. I just double checked it again, they were on the loose side, but still knock persistent after I adjusted as malik sudjested to in 0.10 and ex 0.15

I am thinking need to do leak down test, or start stripping the head. Looks pretty straight forward but one bolt is difficult to get to, on intake the lover one, it is under the rubber boot

[Dirk_S]

I am thinking need to do leak down test, or start stripping the head. Looks pretty straight forward but one bolt is difficult to get to, on intake the lover one, it is under the rubber boot

Allen head, right? I think I know that bolt you’re referring to. Ball-end allen wrench is your friend. Or trim down the short end a tad more.

[Moparnut72]

I cut Allen wrenches down as needed, they don't cost much. I am always afraid of using the ball end in fear of messing up the socket on the bolt. I have a drawer loaded with modified tools. Cutting and grinding on tools will also give an idea of the quality of the tool. I have turned down sockets to fit in a recess, others the tool steel will barely scratch them.
kk

[xorti]

Quick update now that I’ve pulled the head.



The head is off and I’ve inspected the valves.
The valve guides look ok, good valve guides, I have not measured the rocking of the valve but it feels solid
https://youtube.com/shorts/7AkjijF18X4

The exhaust valve looks OK — I can’t see any obvious burns, chips, or damage.

The intake valve has quite a bit of carbon buildup, including deposits on the valve seat area.










https://www.youtube.com/shorts/bpqidES31og

My current theory is that the valve stem seal may have started leaking, allowing oil into the intake.





Over time that likely caused the carbon buildup on the intake valve. A piece of carbon may have broken off and gotten trapped between the valve and the seat, preventing the valve from sealing properly.

That would explain:

• Lower compression on that cylinder
• The ticking sound
• Black residue inside the intake manifold

The piston and rod feel solid with no noticeable play, so the bottom end appears to be fine.



So, need to clean everything with light lapping to see if valve get good contact with seat,

need to buy few parts:

• New gaskets
• Valve steam seals

I’ll update again once everything is cleaned and I’ve tested the valve sealing.

[Moparnut72]

It looks to me that you are getting leakage through the intake valve. It doesn't take much erosion for that to happen. I did all the valves when I worked in the aircraft radial engine shop. I tested them with mineral spirits for leakage. I could get them to pass the test, however one brand, Wright, had the heads screwed on the barrel. We tested those with compressed air to look for leakage at this joint. It was amazing how many cylinders would pass the mineral spirits valve leak test but allow compressed air through. I would have liked to test all the cylinders that way but didn't have the proper fixture to do it.
kk

[MattP]

looks to me oil  l
coming from scored bore piston and or rings ,pull cilender have o look nothing in the photos of head stuff would cause  knock . ristpin bush piston slap deteation from oil ect. look at piston in your photo no carbon on  out side of piston top. black oil rite from blowby , you are there pull the clinder then you will know , piston bore isue and or wrist pin bush  or rod  big end. two min.s to check.    Or  put it back to gether and start all over . you are there  do it

[MattP]

oh sorry the oil in the intake port and  all over the valve is confusing you ok? so much oil in the combustion chamber carboned up valve to the point of leaking the oil contaminated compreshin charge by the intake valve. ok ?

[xorti]

Thanks everyone. After my previous post I pulled the cylinder and unfortunately found the issue. It turned out not to be a valve problem as I initially suspected, I think I just wanted to believe it was something simpler.

The actual problem is a big-end bearing failure on the right cylinder. When I removed the cylinder I discovered that the connecting rod has vertical play on the crankshaft.

https://youtube.com/shorts/VqWciUuZBzU

Unfortunately this means the issue is in the bottom end of the engine, so it’s not a simple top-end repair like I was hoping.

At this point I’m deciding whether it makes sense to find a replacement engine or part the bike out, as a full rebuild may not be economical. Breaking it for parts is also a bit of a hassle, so I’m still considering the options

[Dirk_S]

Oof. Yeah, that ain’t good movement. I rebuilt my V7 II motor due to a big end bearing failure, but that was completely my fault (starved the engine of oil). If you have automotive mechanical experience, these Guzzis are right up your alley.

THAT SAID—Correct me if I’m wrong, but…do I see the bolt heads on the con rods facing out toward the piston?? Because  if so, and if the journal isn’t damaged, that might not require the frame split and the engine pulled apart. Pull both cylinders, and simply do the job through the cylinder holes, right?

[xorti]

Oof. Yeah, that ain’t good movement. I rebuilt my V7 II motor due to a complete big end bearing failure, but that was completely my fault (starved the engine of oil). If you have automotive mechanical experience, these Guzzis are right up your alley.

THAT SAID—Correct me if I’m wrong, but…do I see the bolt heads on the con rods facing out toward the piston?? Because  if so, and if the journal isn’t damaged, that might not require the frame split and the engine pulled apart. Pull both cylinders, and simply do the job through the cylinder holes, right?

Thanks. The bolts are facing downwards, so unfortunately they’re not accessible through the cylinder opening, it would be very difficult to reach them that way.

This bike likely had the same issue as yours. When I bought it, the oil sensor wire was disconnected, and the engine was already low on oil. It’s hard to say how long it was run like that, but it definitely looks like oil starvation.

What’s a bit annoying is that on the Moto Guzzi the oil pressure light works the opposite way, if the sensor wire is disconnected, the dash doesn’t show a warning. So the previous owner may have ridden it without realizing there was a problem.

If the failure was caused by low oil, I’m also concerned there could be other damage, like scoring on the piston or cylinder, and potentially wear on the other crank bearings as well.

At that point I’m not sure a rebuild would be worth it compared to finding another engine for reasonable price, alternatively I can always try sell my bike for parts

[turboguzzi]

regretfully small blocks have very low oil capacity, tend to use some too,

means if you dont keep checking level often, you might miss it going too low and by that time, its too late, bottom end damage done.

when you put it back together, id add this:

https://www.ebay.com/itm/126603173765

that said, inlet valve shows someone skipped adjustment a few times, not you i guess :)

[chuck peterson]

Wasn’t there quite a ruckus about oil suddenly disappearing when the post baby breva smallblocks came out?

I believe Mr Roper warned that a sump extender and an additional bit of oil was necessary, in contrast with big blocks that needed the sump but no additional oil. The 1.8 liters as original was unexpectedly disappearing quite by itself without any notice beforehand. Just whoop, and you’re out of oil with a scorched motor.

I haven’t heard anything about that since the initial discovery. Maybe you’ve found one

[Kev m]

Wasn’t there quite a ruckus about oil suddenly disappearing when the post baby breva smallblocks came out?

I believe Mr Roper warned that a sump extender and an additional bit of oil was necessary, in contrast with big blocks that needed the sump but no additional oil. The 1.8 liters as original was unexpectedly disappearing quite by itself without any notice beforehand. Just whoop, and you’re out of oil with a scorched motor.

I haven’t heard anything about that since the initial discovery. Maybe you’ve found one

Actually it wasn't the POST baby-breva - it WAS the Baby Breva and V7C - i.e. the problem only surfaced on the dual-throttle body smallblocks that ended ~2012 with the introduction of the MK1 - SINGLE Throttle Body models.

I remember distinctly because I installed an extended sump on my 2013 MK1 shortly after delivery anticipating the same potential problem.

But it turned out that something in the MK1 redesign seems to have solved it because we've not heard of such a thing on the single throttle body motors.

Of course this being a V7C - yes, I would think that could be a possibility.

[Moparnut72]

Even if you could get the rod out the crank is certainly going to need reconditioning at the least if not replacement. I  have an 850 T3 motor with a very wiggly rod. I got a replacement engine with the project instead of trying to repair the original. I had something similar happen to a Studebaker V8, the crank was scrap metal.
kk

[MattP]

yeh lets see the bore

[malik]

Actually it wasn't the POST baby-breva - it WAS the Baby Breva and V7C - i.e. the problem only surfaced on the dual-throttle body smallblocks that ended ~2012 with the introduction of the MK1 - SINGLE Throttle Body models.

I remember distinctly because I installed an extended sump on my 2013 MK1 shortly after delivery anticipating the same potential problem.

But it turned out that something in the MK1 redesign seems to have solved it because we've not heard of such a thing on the single throttle body motors.

Of course this being a V7C - yes, I would think that could be a possibility.

I bought a V7C that this happened to - according to the original owner, oil would be gone around 600km. Have not yet taken the engine apart to have a look. Now it looks like this symptom might also have struck a mate's NTX 650 - engine seized at around 800km after service. At present in the process of replacing the engine with one from a1TB V7 Mk 1. Once we have managed to get that running we plan to examine both the seized engines to see what we can find. I also haven't heard of this happening to a 1TB.

[chuck peterson]

Thanks everyone. After my previous post I pulled the cylinder and unfortunately found the issue. It turned out not to be a valve problem as I initially suspected, I think I just wanted to believe it was something simpler.

The actual problem is a big-end bearing failure on the right cylinder. When I removed the cylinder I discovered that the connecting rod has vertical play on the crankshaft.

https://youtube.com/shorts/VqWciUuZBzU

Unfortunately this means the issue is in the bottom end of the engine, so it’s not a simple top-end repair like I was hoping.

At this point I’m deciding whether it makes sense to find a replacement engine or part the bike out, as a full rebuild may not be economical. Breaking it for parts is also a bit of a hassle, so I’m still considering the options

That youtub video is HORRIBLE, I can’t take it, STOP! STOP!!!!! So sorry you’ve had this happen…