Stornello rebuild

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Rick Yamane

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May 16, 2024, 11:40:51 PMMay 16
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I need to rebuild the top end of my Giro Stornello. Has anyone got any opinion on the best bet to find parts in one place rather than a part here, a part there.....
I have an email off to Guzzi Retro but haven't heard back yet. Were people having trouble with Valenti's service? It also looks like guides are not available as a service part. I'm guessing maybe Kibblewhite can make them?

Alan Comfort

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May 17, 2024, 1:30:14 AMMay 17
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You could try K-Line valve guide liners for resurrecting the valve guides and King of Pistons for pistons and rings. Stein Dinse has gaskets for the Lodola 235. They might have smething fot the Stornello?? If you order through Valenti or GUZZI Retro they will probably arrive eventually. There is a gasket set on eBay: https://www.ebay.ca/itm/175327253248
Alan in Roberts Creek

On Thu, May 16, 2024 at 8:40 PM Rick Yamane <ri...@motionpro.com> wrote:
I need to rebuild the top end of my Giro Stornello. Has anyone got any opinion on the best bet to find parts in one place rather than a part here, a part there.....
I have an email off to Guzzi Retro but haven't heard back yet. Were people having trouble with Valenti's service? It also looks like guides are not available as a service part. I'm guessing maybe Kibblewhite can make them?

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Don West

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May 17, 2024, 3:45:45 AMMay 17
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Hi Rick  
What parts are you needing?  Harpers stock quite a few Stornello parts in the States.  Look up the part numbers and use those to search their website.
The valve guides are a very simple phosphur bronze sleeve and wouldn't be difficult to make on a lathe. 
You will need a seal kit that includes the rubber push rod tube seals and square section O rings that go around the head studs under the rocker assembly. 
If you are replacing the piston, watch out for the size of the gudgeon pin as they come in two sizes, 14 and 15mm.  Measure your small end before ordering. 
I make my own gaskets for the rocker cover etc from gasket paper as I have found ones that i have bought have been way off shape.
Don West 


On Friday, 17 May 2024 at 04:40:52 BST, Rick Yamane <ri...@motionpro.com> wrote:


I need to rebuild the top end of my Giro Stornello. Has anyone got any opinion on the best bet to find parts in one place rather than a part here, a part there.....
I have an email off to Guzzi Retro but haven't heard back yet. Were people having trouble with Valenti's service? It also looks like guides are not available as a service part. I'm guessing maybe Kibblewhite can make them?

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RICHARD YAMANE

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May 17, 2024, 11:31:53 AMMay 17
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Hi Don,
I need pretty much everything. I showed this little guy no mercy for two full Giros and some local rides. Not sure how many miles were on it when I got it but it is beyond well used at this point. It's got about .020" cylinder taper, the valves are very loose in the guides and the exhaust valve seat was carboned up. After hitting it with the wire wheel its lightly pitted too. This is a true tribute to the ruggedness of these engines. Nothing broken or failed, just worn to the point where it couldn't run anymore.
I did replace the rubber seals and gaskets a couple of years ago. I pulled the head for a "look see" in prep for the Giro d' California 2022. The pushrod seals were leaking at that time.
I had forgotten about Harpers. I'll give them a look. 
Got the part numbers already, sent the list to Guzzi Retro. No email back yet this morning. I was surprised the valve guides do not show up as a separate part. There were two piston options but It appears there was a flat top and the domed Sport piston. Only one pin so the smaller pin might be for the older engines. 
Interesting the ISDT shows a chrome bore and different, presumably forged piston. If I get desperate I might pull the cylinder/head from my ISDT. I'm sure that is well worn too but at least I know it was running (when parked) Hahaha.
What a remarkable little engine!

Rick Yamane
Importer of Vape/Powerdynamo ignition systems and Polisher of bikes at Motion Pro

Don West

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May 17, 2024, 12:14:51 PMMay 17
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They are great little engines.  It was designed by Guilio Carcano, he also came up with the legendary Guzzi V8 racer, so he must have known a thing or two about engine design. 
Valve guides are available, part number 55036626.  Harpers list them on their website, they also stock a piston on the third oversize. The flat top piston is for the Turismo model, you will be wanting the domed piston for your Sport America. 

On my latest project, I have done a good upgrade to the electrics.  As standard, the upper coil has two windings, one to do the AC direct lighting and the second is for the battery charging circuit.  Both citcuits use the frame as the earth.  I have had this coil rewound by a company in England as a single winding with 2 output wires.  I have connected these up to a modern solid state 12volt rectifier/regulator and fed the output into a 12volt battery.  I have then reconfigured the wiring so the headlight etc is fed by battery voltage.  I am using an LED headlight and it seems to work well. 

Make sure you clean out the centrifugal oil filter in the left side of the engine whilst giving it a once over. 

Don 



RICHARD YAMANE

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May 17, 2024, 12:43:58 PMMay 17
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Great! I'll get with Harper's.
I run a Vape Powerdynamo. It's 12v and gives a strong spark at low crank speed. I've been running them and importing for friends for about 25 years. I've been pretty happy with them and their service and ship times have improved since the German founder sold the company to Vape. They were the CZ producing the componentry for the Germans anyway.

Rick Yamane
Importer of Vape/Powerdynamo ignition systems and Polisher of bikes at Motion Pro

Rick Yamane

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May 17, 2024, 1:17:25 PMMay 17
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Thanks Don!
Harper had everything I need listed. The valves are on a pre-order so I'm hoping to hear back on a time frame.
Thanks for the reminder on the oil "filter" too. I did clean it on my ISDT when I built my trials bike but had forgotten about it on the Sport till now.
I saw Stein Dinse had exhaust valves. I'll check them again to see if they have intakes too. Only $70 for the pair from Harper so if I end up with spares it's fine.
Also, I had the part number for guides. I think it was valve seats that are not available separately. 
From: guzzi-...@googlegroups.com <guzzi-...@googlegroups.com> on behalf of RICHARD YAMANE <richa...@comcast.net>
Sent: Friday, May 17, 2024 9:43 AM
To: guzzi-...@googlegroups.com <guzzi-...@googlegroups.com>
Subject: Re: [guzzi-singles] Stornello rebuild
 

Don West

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May 17, 2024, 1:30:23 PMMay 17
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Watch out when ordering valves, the Turismo ones have a smaller stem siameter diameter. 
You would need 55036025 inlet and 55036125 for the exhaust. 
Do you have the parts book?  There is also a very useful service sheet that is printed in English and gives some reasonable technical details.  You can download a copy from here if you need it. 

Don 

RICHARD YAMANE

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May 17, 2024, 1:55:24 PMMay 17
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Yep, those are the numbers. I have a copy of the parts book, probably downloaded from either Guzzi Retro or Valenti on a previous order.There is also a website with a lot of Italian manuals that I pull stuff from as well.
I don't think I have the service sheet so I'll check it out.
Thanks again!

Rick Yamane
Importer of Vape/Powerdynamo ignition systems and Polisher of bikes at Motion Pro

RICHARD YAMANE

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May 17, 2024, 2:00:41 PMMay 17
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The service sheets are from the Intertec Vintage Collection manual for four strokes. We have both the four and two stroke books on the shelf. They've been very helpful for me since I work on such a wide array of bikes.

Rick Yamane
Importer of Vape/Powerdynamo ignition systems and Polisher of bikes at Motion Pro

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