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1984 Moto Guzzi V65

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Mandello Cafe:
A few months ago, I purchased a 1984 Moto Guzzi V65 SP. The poor thing had been sitting for at least a decade and must have spend some of that time outside. Outside in this case meant different places in Texas. While the bike was largely complete a restauration to original condition seems unreasonable. Instead the plan is to largely repair, service and rebuild with a basic “Naked” bike focus. I purposefully avoiding the term “Cafι” as I am trying to steer away from LED headlights, exhaust wrap, cute leather pouches (in replacement of side covers), headlight grills and skinny jeans.

This is how things looked like when the Guzzi arrived:











After I hauled the Guzzi home, I performed the following tasks:
•   Replaces lubricants in engine, transmission and final drive;
•   Rebuild the both PHB 30 carbs;
•   Rebuild the centrifugal advance function on the ignition, replaced points and capacitors;
•   Set static timing;
•   Rewired a new ignition switch (bike came without keys);
•   Set valve gap (only minimal adjustments needed);
•   Reactivated the rear brake caliper and disabled the linked front caliper (was disconnected by a previous owner to move the bike).
•   Rigged a makeshift fuel tank out of the oil can that held the transmission oil (the Guzzi tanks has some corrosion that needs to be addressed)
At this point I was able to start the engine and ride the bike at low speed. I was able to shift through all five gears and get a basic carb setting. No nasty noises. No neighborhood pets were killed while riding with only the rear caliper and the brake performance of a 10 speed bicycle on a rainy day. The fun ended when I ran out of the less than a liter of gas my Valvoline transmission oil makeshift gas tank would hold.

Yeah! (so far)

Mandello Cafe:
To address the corrosion inside the Guzzi's gas tank I initially built a rig to tumble the tank. I had read many opinions and strategies on the web concerning the topic of rust removal and decided against the chemical route. Here is a video of the contraption I came up with.

https://www.youtube.com/watch?v=Mhxyo6r2TTA




The stuff that is tumbling inside my tank is sandblasting sand and a chain. A laundry dryer will do a better job if you want to tumble the tank over its major axis rather than side to side. The tank is clean - as far as I can tell/see (it is really difficult to see much of anything inside a V65 SP tank). The sand and dust blown out / washed out and the tank is installed and filled.

So much better than a 1L Valvoline transmission oil can moonlighting as a gas tank.  :wink:

Mandello Cafe:
So with the tank tumbled, some mild dents removed and back on the bike, I took another test ride. Things went well and a real tank is so much more enjoyable than a 1l Valvoline oil can moonlighting as a makeshift tank. I should have left things at that, but … 
The compression test showed the following:
•   Right side 0- 120 PSI
•   Left side – 165 PSI

That was last weekend, yesterday I decided that I would pull the right-side cylinder and look any potential evil square in the eye. Said and done – removing cylinder head and cylinder from a small block Guzzi is super easy. I could do this by the side of the road (not sure what this would help...).

This picture shows the first look in the bore and there was some initial rejoicing.




Some damage here on the very top of the cylinder bore – past the point where a piston ring would have to move.




Some damage to the piston in the top land ring area matching the location of the damage in the cylinder bore.




My experience with diagnosing the extent of engine damage is limited. I only own one other Nikasil coated cylinder that was cast in the fires of Mt. Giladorni (2-stork cylinder for a Vespa). It seems that the location of the damage above any area that is reached by the piston rings would not contribute to a loss of 45 PSI. I do not see any obvious damage to the cylinder head – no cracking between valve seats or seat and spark plug hole. I think I see some traces that may support that the cylinder head gasket was not sealing perfectly in the lower quadrant.
I would like to see some assessments of seasoned Guzzi folks that have inspected other cylinders. Let me know if you need other shots, angels or better quality pictures.

Thanks, Patrick

Frenchfrog:
Great to have a small block thread in this section ! With regards to the low compression have you checked the valves ...sound obvious doesn't it  :grin:

Antietam Classic Cycle:
I would probably pre-emptively replace the valves - they aren't expensive and it can be quite costly when the head pops off of one and destroys the head and piston. Been there, seen that...

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