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










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[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