V65 carnage

[Antietam Classic Cycle]

I'm working on a V65SP for a gentleman, correcting some electrical and brake issues mostly. I found that one of the green Dyan coils was cracked, so yesterday he stopped by to drop off a newer, good green coil. Installed that yesterday afternoon and pulled the plugs to check for spark - good spark.  I decided while the plugs were out, that I'd check compression. Left side (cold, throttle wide open) - 110 psi. Hmm. Okay, right side - 0 psi! Huh? Let's try a different gauge. Same result. Hook up the leakdown tester - 100% leakage, air blowing out the exhaust. Look in the plug hole - the top of the piston is all beat up. Uh oh. 1/2 hour later the head is off and the problem is readily apparent. 



Remnants of the valve folded over and stuffed back into the exhaust port.




Replacement cylinder w/piston, cylinder head and four new valves, guides, seals, etc. all ordered.

[oldbike54]

 Damn , that is brutal  Not sure I've ever seen a head quite that banged up .

 Dusty

[pete roper]

Don't worry about it. It'll ride up with wear!

Used to be more common on V65's than 50's except the Monxas.

[Devildog]

And the owner wasn't aware of any of this?

[Chuck in Indiana]

"Did seem to be a little down on power.." 

[Lannis]

And the owner wasn't aware of any of this?

Certainly a candidate for the "Ran When Parked" wheeze if it were up for sale ... !

Lannis

[Devildog]

I installed shorter handlebars on my V65C, and didn't install both throttle cables right, it was seriously down on power, running on one cylinder. Finally figured it out. You do learn a lot messing with a Guzzi.

[guzzisteve]

I just sent a head that looked similar cept it was off a Lario to an artist friend to be part of an art project. Finally trying to thin out all these junk left over from fixin junk Guzzi's. I got enough 'not good' cyls to do a radial motor for art, every other one from sq to round.

[Guzzi Gal]

Don't worry about it. It'll ride up with wear!

Used to be more common on V65's than 50's except the Monxas.

Ha, love that show!

[jacksonracingcomau]

I’ll raise you 3 valves

[voncrump]

It's a real shame that Guzzi let these small block engines down with the use of substandard valves. I replaced a V50 exhaust valve in the 1980s. The engine was down on compression and I found it had tight clearance on one valve. I adjusted the clearance and ran the bike again before rechecking the compression. The compression had come up but not to an equal with the other cylinder. So I stripped the cylinder head. The valve was damaged so I replaced it. It was a good repair, the bike ran well. After the job was finished I inspected the damaged valve further. The valve stem under the head of the valve had stretched and thinned. Out of curiosity I put the valve in the vice and gave the valve head a little tap with a soft faced hammer. The valve head broke ioff and shot across the workshop. I went to my stack of junk and picked up a Honda valve that came out of an engine that blew up. The Honda valve was already bent so I put it in the vice and tried to break it with the soft hammer.  Well I bent it back and forward several times before I gave up. Conclusion: substandard valves. My opinion.
Cheers, voncrump

[huub]

dont forget to change the valve springs for post 1990 single springs.
the stiff original ( double)  springs are the main reasons why valves snap.
i used to tun a V65TT as daily transport , i routinely changed the valves when they started to stretch, usually after 50-60.000 km
valves are cheap , a dropped valve isnt.
you know when they start to stretch, suddenly the tappet clearance is gone.
after the last rebuild changing the springs and valves the problem disappeared.

[Chuck in Indiana]

^^^^ wat HUUB sez. Except for Larios, of course. 

I just sent a head that looked similar cept it was off a Lario to an artist friend to be part of an art project. Finally trying to thin out all these junk left over from fixin junk Guzzi's.

Milich has one for sale like that. I think he wants $299..

[Groover]

I wonder if the owner heard a "strange noise" at any point...

[huub]

^^^^ wat HUUB sez. Except for Larios, of course. 

dont tell me , i've graduated to a lario as daily transport, and it isnt on its first engine....

[twowings]

Great Scott! I guess it took a while to stop when the noises started!! Talk about a box of rocks...

[normzone]

" I'm working on a V65SP for a gentleman, correcting some electrical and brake issues mostly. "

Yep, that's definitely an electrical braking issue. Or maybe more like an electrifying breaking issue.

[voncrump]

dont forget to change the valve springs for post 1990 single springs.
the stiff original ( double)  springs are the main reasons why valves snap.
i used to tun a V65TT as daily transport , i routinely changed the valves when they started to stretch, usually after 50-60.000 km
valves are cheap , a dropped valve isnt.
you know when they start to stretch, suddenly the tappet clearance is gone.
after the last rebuild changing the springs and valves the problem disappeared.

I forgot about the Guzzi strong springs. That would also be a major part of the problem. I didn't notice any thing unusual about the springs when I repaired the V50 but I definitely noticed with the Lario. The real danger here is that sometimes the motors are still running OK as the valves are stretching. Adjustments are made and then BANG. I have a friend with a V11 that closed a clearance up. I suggested that he replace the valve or at least strip and check it for maybe valve seat recession or a loose seat but he adjusted it and continues to ride it. I totally agree with huub on the replacement strategy. Also we now know a lot more about the valve Spring issue and fix. Hell even Guzzi woke up to the problem. Does anyone know if the valves are a different part number now? The valves in the later V7 engines might still be the same as say a V65.  I don't think the size of the valves changed much. I will try and check some of my old paperwork for the V50 part number in the 80s.
Cheers, voncrump

[Antietam Classic Cycle]

dont forget to change the valve springs for post 1990 single springs.
the stiff original ( double)  springs are the main reasons why valves snap.

With the later springs, does one need to change to the later spring seats and upper retainers as well?

[huub]

the spring doesnt fit the retainers out of the box, you need to file the spring seat  0,5 mm,
spin the retainer in a lathe/powerdrill and use a chainsaw file .
only takes a couple of minutes

[Antietam Classic Cycle]

the spring doesnt fit the retainers out of the box, you need to file the spring seat  0,5 mm,
spin the retainer in a lathe/powerdrill and use a chainsaw file .
only takes a couple of minutes

Or I can use the later retainers and seats and skip all of that?

[huub]

Or I can use the later retainers and seats and skip all of that?

yes but that would be quite expensive, just to save a couple of minutes of work.

[Antietam Classic Cycle]

yes but that would be quite expensive, just to save a couple of minutes of work.

Not really. I've ordered four each springs, retainers, seats and the total is under $35 not including shipping. Whether any of it is actually in stock remains to be seen.

[Chuck in Indiana]

Yeah, I bought enough stuff to do a top overhaul on the Monza if/when needed, and the ticket was less than a hundred bux.

[mtiberio]

Charlie is working on my buddy Steve's bike. While I can't comment on how the bike ran with a loose head of an exhaust valve rattling around, I speak with Steve often, giving him Guzzi advice, and he never once mentioned "lack of power" or "rattly noise" as an issue with his V65. Before you wonder if my buddy Steve is compos mentis, he is in his late 70's, rides every day, and is a modern renaissance man, quite brilliant actually.

FWIW, once, the pinion bearings in his rear drive unit disintegrated. Both bearings, totally... His complaint, "the bike made a clicking noise when he rolled it backwards". I was over at his house, and we pulled the rear wheel and rear drive. You could have knocked me over with a feather when I saw the pinion flopping loose in the rear drive housing. Just another example of how Guzzis can, all depending, run to within an inch of their life.

Another similar tale, a different friend came over to the garage, complaining that his bikes clutch felt funny and had trouble shifting. His crankshaft was broken in half. Previous owner had torched the rod bearings. The shop that ground the crank put an inadequate radius at the edges of the bearing surface. It broke in half at one end of the rod bearing, but the jagged edges of the break held the crank together. The clutch issue, well the rear half of the crank was wiggling fore and aft, which messed up the clutch push rod action...

[Rough Edge racing]

 "Down on power", now that's funny....I had the ignition on the Cali2 cafe bike crap out and rode about 50 miles on one cylinder...It was so damn obvious, it was a struggle to maintain 50 MPH and the bike shook like a wet dog....Same on old Triumphs......

[Rough Edge racing]

 I find the damage interesting...Do the V65's have a tendency to detonate with low grade fuel or if lugged?  I showed the photos to a few race engine builders.... They mentioned a possibility of detonation overheating the valve so it sticks in the guide...then the piston pummels it pieces....Just wondering...

[Chuck in Indiana]

I find the damage interesting...Do the V65's have a tendency to detonate with low grade fuel or if lugged?  I showed the photos to a few race engine builders.... They mentioned a possibility of detonation overheating the valve so it sticks in the guide...then the piston pummels it pieces....Just wondering...

I've never heard it, but I'm as deaf is a post. That said, I don't lug them or use low grade fuel, either.

[Antietam Classic Cycle]

I find the damage interesting...Do the V65's have a tendency to detonate with low grade fuel or if lugged?  I showed the photos to a few race engine builders.... They mentioned a possibility of detonation overheating the valve so it sticks in the guide...then the piston pummels it pieces....Just wondering...

The problem(s) are crap o.e. valves and too much spring pressure. Detonation has never been a problem on the Heron head small blocks.

[Chuck in Indiana]

Also, with the Heron head, I would think that the piston might just push a stuck valve out of the way. (?)