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V7 Sport catastrophic failure

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Missionguzzi:
A friend brought me his 1972 V7 Sport after it stopped running during an easy Sunday-morning ride. I checked first for spark - got none on either side. Removed the valve covers and noticed that the valves on neither side were opening or closing. Engine was able to turn over freely, but camshaft wasn't moving at all. Removed both jugs and the timing cover and found the cam gear broken into 2 big parts and a couple of small pieces. See pictures.  Wondering about potential causes other than metal fatigue.  Camshaft seems OK, but could have undetectable defects, cam journal appears unscathed.  Also needing a compatible camshaft (850-T, T-3?) and all 3 timing gears to replace the broken or compromised parts.  All input welcome.  Thanks.








the western wind poem

Antietam Classic Cycle:
That happens on Ambassadors and early Eldos sometimes and is chalked up to a casting flaw. The "small hole" gears usually don't fracture, just the roughly cast "large hole" ones.

Doubt there's anything wrong with the cam. It wasn't used on any other model sold in the US - the grind is unique. A T and T3 cam would work. 

Check with Mark Etheridge at Moto Guzzi Classics (562-986-0070) and Paul Szostak (his contact info. is here: Michigan Rep. - South https://www.mgnoc.com/staff_and_reps.html) for the gears, Paul might even have a cam. Joe Walano "The Guzzi Doctor" might also have what you need. https://theguzzidoctor.com/

Don G:
Wonder if any valves met a piston?

Huzo:

--- Quote from: Don G on September 16, 2025, 07:18:56 PM ---Wonder if any valves met a piston?

--- End quote ---
First thing I thought.
The valves themselves will not have collided with each other because the camshaft is keeping them in time relative to each other, but your fear of piston collision is well founded

faffi:
I would remove carbs and exhaust for a visual inspection of the valves, then do a compression test after reassembly if there were no visual clues of any bent valves. A bore scope can also be telling. As I type, I came to think that a leak-down test as it sits can tell you everything you need to know about the condition inside each cylinder.

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