General Category > Bike Builds, Rebuilds And Restorations Only
1984 Moto Guzzi V65
Mandello Cafe:
Frenchfrog, I have tested the valves/head by filling exhaust port and intake port with a cup of water. The exhaust side is pretty tight - maybe a drop of seepage every few minutes. The intake side does not seal as well - about a drop every 10 seconds. I will have to come up with a way to compress the valve springs and take the valves out to inspect valve and seat better.
Charlie, From reading stuff it sounded like the Lario's were the ones that had more issues with valves shearing off. I read something about the 2 valve heads having occasionally issues with exhaust valve shafts lengthening and eventually failing. That did not sound like a very spontaneous event on the 2 valve heads. Did I misunderstand things? Also the parts support on those 80's small blocks seems poor (did not realize this when I got the bike). I do not want to replace the stock valve with an aftermarket part that may have even less of a lifespan / track record. Did you swap out both (intake and exhaust) valves? What product did you use?
Devildog:
Just curious, what is the mileage on the bike?
Mandello Cafe:
Antietam Classic Cycle:
--- Quote from: Mandello Cafe on January 01, 2020, 07:49:02 PM ---Charlie, From reading stuff it sounded like the Lario's were the ones that had more issues with valves shearing off. I read something about the 2 valve heads having occasionally issues with exhaust valve shafts lengthening and eventually failing. That did not sound like a very spontaneous event on the 2 valve heads. Did I misunderstand things? Also the parts support on those 80's small blocks seems poor (did not realize this when I got the bike). I do not want to replace the stock valve with an aftermarket part that may have even less of a lifespan / track record. Did you swap out both (intake and exhaust) valves? What product did you use?
--- End quote ---
Here's a few photos. This was on a V65SP with 24k miles. I had just replaced a failed Dyna coil and was checking for spark with the new/used one. Thought I might as well check compression too - left cylinder: 130 psi, right cylinder: 0! Pulled the head off and this is what I found:
The head of the exhaust valve is folded in half and stuffed into the exhaust port.
Piston took a beating.
The left side exhaust valve was getting ready to fail as well - it's bulged where the stem and head are welded together. Good valve on the left, ready to fail on the right.
I bought a good used head, piston and cylinder from Ed Milich. Heads rebuilt with new valves, guides, seals, Nevada 750 springs, seats and retainers.
I used these parts:
http://www.mgcycle.com/index.php?main_page=product_info&cPath=68_127&products_id=2583
http://www.mgcycle.com/index.php?main_page=product_info&cPath=68_127&products_id=4401
http://www.mgcycle.com/index.php?main_page=product_info&cPath=68_127&products_id=2572
http://www.mgcycle.com/index.php?main_page=product_info&cPath=68_127&products_id=2687
http://www.harpermoto.com/lower-cup-31037015.html
http://www.harpermoto.com/upper-cup-31038015.html
http://www.harpermoto.com/outer-valve-spring-27037521.html
Mayor_of_BBQ:
A really great and fun bike to ride, and a super base for a restomod!
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version