V50iii vs. Ambo (first MG)?

[Mwether]

This ^^^. Unless the T3 cylinders were Gilardoni or replated originals, it's not a good fix. The T3 pistons are different - piston pin location 4 mm lower, so hopefully a) they didn't use the pistons too, or it will have super low compression, and b) if they used the Ambassador pistons, they match the cylinders (pistons and cylinders are "graded" A, B and C and should be matched).

Look between the two bottom-most cylinder fins and check for "GILARDONI" cast in. If nothing there, and if the seller will let you, remove a sparkplug, make sure the piston is down away from TDC, then insert a "pencil magnet" in through the plug hole and touch the cylinder wall. Zero magnetic attraction = chrome, very slight = Nikasil/Nigusil, strong = iron liners.

Charlie, total noob stuff here...

Just to be sure I'm following along at home (and assuming that the Ambo in question was fitted with 88mm Gilardoni heads), am I correct that:

• Gilardoni makes 88mm aftermarket pistons with varying piston pin locations.
• I need to be sure that the correct pistons (with the Ambo-specific piston pin location) were installed in the 88mm heads.

[Antietam Classic Cycle]

Charlie, total noob stuff here...

Just to be sure I'm following along at home (and assuming that the Ambo in question was fitted with 88mm Gilardoni heads), am I correct that:

• Gilardoni makes 88mm aftermarket pistons with varying piston pin locations.
• I need to be sure that the correct pistons (with the Ambo-specific piston pin location) were installed in the 88mm heads.

There are no "88 mm Gilardoni" (cylinder - not head) kits for Ambassador - never were. The 88 mm kits are for Eldorados, 850-Ts and T3s. They would not work on an Ambassador unless the crankshaft was swapped for one from an Eldorado. Possible, but not likely.

You wrote that the seller stated that "T3 cylinders" were used. Those have an 83 mm bore, not 88 mm. The stock Ambassador 83 mm pistons would work in those cylinders, but as I wrote earlier: "(hopefully) they match the cylinders (pistons and cylinders are "graded" A, B and C and should be matched)." If the T3 cylinders they used had chrome bores, then nothing has been gained - they will still need to be replaced. There are no Gilardoni (or other brand) cylinder kits for Ambassador available at this time, so replating is really the only option. Some would say that installing iron liners is another option, but that will cost just as much if not more than replating, and will not run as quiet or cool as replated cylinders.

[Mwether]

Thanks, Charlie. That's very helpful.

I'm hopeful the seller will be able to explain more specifically what's been done to remediate the chrome plating problem...

[Frenchfrog]

I think you also need to take into account the spares availability for the V 50 II which honestly is not that good ...the small block cranks cannot be machined for oversized bearings as no such bearings exist officially for example.The Cam chain has been NLA for decades now and I do not think that there are substitutes available either.No Piston/barrel sets either,the bosch ignition system is NLA and the alternatives expensive.Small block Guzzi parts are often much more expensive than big bloc equivalents too.
There are of course specific Ambo parts that are NLA too but I suspect that there are more options to use adaptable parts on these than on the V 50 II .

[Mwether]

I think you also need to take into account the spares availability for the V 50 II which honestly is not that good ...

Thanks for this! Yet another reason to cross the V50 off the list.

Not sure about the Ambo at this point either. The seller is going to check with the PO about whether he's got any documentation of the refresh/restoration. If there's no record of what was done, I may have to walk away... 

[Antietam Classic Cycle]

To be completely frank... It sounds to me like you might be better off with a new/newish Royal Enfield, Guzzi V7 or V9, rather than an old Guzzi. Owners joke about Guzzis "making mechanics out of riders since 1921" and there is some truth to that. Wrenching on an old Guzzi isn't for everyone, it takes a lot of dedication, a certain degree of mechanical aptitude and a willingness to learn even more. I've been tinkering with stuff from a very young age, so old Guzzis are a natural fit for me, but they just aren't for some people.

[Mwether]

Thanks, Charlie. You may be right...

Does this give you (or anyone) enough confidence to move ahead?

About documentation of the work, the previous owner says:

"No paperwork. Bought them [850 cylinders] from a Guzzi guy in Maine online. He said they came off his running good 850T. He just wanted 1000cc kit. Valves, guides were bought new from MG Cycle. Valve job and guide installation was done at a local machine shop."

That doesn't tell me anything about whether the chrome plating of the donor cylinders was addressed...

[Antietam Classic Cycle]

Thanks, Charlie. You may be right...

Does this give you (or anyone) enough confidence to move ahead?

About documentation of the work, the previous owner says:

"No paperwork. Bought them [850 cylinders] from a Guzzi guy in Maine online. He said they came off his running good 850T. He just wanted 1000cc kit. Valves, guides were bought new from MG Cycle. Valve job and guide installation was done at a local machine shop."

That doesn't tell me anything about whether the chrome plating of the donor cylinders was addressed...

Sure doesn't instill confidence in me. Sounds like they just swapped out obviously bad chrome cylinders for chrome cylinders that might not have been flaking yet. Lateral move, nothing gained. At least the heads were rebuilt. 

[AJ Huff]

Where is this Ambo located? Maybe someone who knows Loops and  what to look for can look at it for you?

-AJ

[Mwether]

Where is this Ambo located? Maybe someone who knows Loops and  what to look for can look at it for you?

-AJ

It's in South Carolina, AJ.

Is there really a way to tell (by external examination) if the cylinders have been replated??

[Antietam Classic Cycle]

It's in South Carolina, AJ.

Is there really a way to tell (by external examination) if the cylinders have been replated??

Replaced, yes. Replated, no. That's where the "magnet test" comes into play.

[Mwether]

Editing the post to get your thoughts comparing/contrasting these two bikes as a first Guzzi:
...

Aaand the answer is: neither...

The V50 was a cobbled-together ii/iii with waning parts availability, etc.

The Ambo had too many unknowns as to the state of its cylinders and exactly what had happened during engine mods.

Onward!