What did you do to or for or with your Laverda today?

I tried one of those helmets with the built in mirror about 10 years ago. It seemed like a good idea to me. It had a reasonable field of view, but I found the optics to be pretty crap, with a distorted and blurry image. I didn't buy it. Maybe they've improved the optics since then.

Anyway, I doubt that having a rear-view helmet would relieve you of the requirement to have mirrors fitted to the bike.
 
Dellortoman said:
Neat job Quentin. You've put some work into that little gadget. It's a bit more complicated than the ones I've made. But all I've ever tried to achieve with fairing supports going to the steering centre is to stop the fairing wobbling about. Never had the additional problem of mirrors hanging off the end.

Your fairing actually has a frame in that area, but you need a pretty rigid support for mirrors.
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Yeah, more hours whiled away when I should have been varnishing in the extension :eek: The ZXR fairing bracket was originally very different and the rear-facing 'wings' actually faced the other way and were fixed to the frame between tank and head tube - good design - but no room on the Lav for that. A test ride will tell but it's not the most rigid of fairing brackets. The one I made for my previous GSX-R fairing was strong - all triangles!
My prob here was getting the drop past the clip ons/fork caps down to the central fixing nut. I glued a threaded alloy insert into the underside of the top nut and machined a press-fit for a small 19x6mm (ID) sealed ball bearing in the top plate (no friction, Vince). Then had to machine the inserts that fit at an angle into the top plate - getting that angle even close was bloody tricky, and then it was the makeshift milling attachment in the lathe to get square flats at the bottom of the holes top and bottom for the bolts under and inserts over - then Loctite epoxy to set the alu rods in exactly the right place. Of course, the first time I drop it they might bend out of shape!! 'Next time' I'll have 10mm rod all the way from fairing to top plate.
 
Dellortoman said:
I tried one of those helmets with the built in mirror about 10 years ago. It seemed like a good idea to me. It had a reasonable field of view, but I found the optics to be pretty crap, with a distorted and blurry image. I didn't buy it. Maybe they've improved the optics since then.

Anyway, I doubt that having a rear-view helmet would relieve you of the requirement to have mirrors fitted to the bike.
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A 120 Jota owner friend of mine, Dave Blower (sadly now deceased) patented a rear view mirror for a m/c helmet, and I still have a couple of his prototypes which were attached to a full face helmet’s chin guard. I think it worked well but he never managed to persuade a helmet manufacturer to further develop the design, which I think was a missed opportunity. I tried giving it some additional publicity by turning up with one fitted to my helmet at the TT in, I think 1985, but it didn’t go down too well with the ACU.
By coincidence, I came across some of Dave’s patent papers, in the last few days, in a box of stuff from my racing archive.
 
Some may remember that I was knocked off my 3C on March 17th last. I suffered a dislocated thumb and a broken heel which are still giving me trouble. The bike with a full tank of petrol caught fire and burnt.
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The car driver having admitted his entire responsibility in the accident, my insurer paid out the agreed value of the machine which should cover a rebuild. I could have bought another nice one with that money, but this 3C was mine and I had the sweet taste of revenge in my mouth. I'd also had the engine extensively rebuilt by Keith Nairn with 78mm pistons needing new liners and the cases opened out, a rebuilt crank with Arrow rods and dynamic balancing.
I took bits off the bike over the last couple of months, all the while buying parts to rebuild it, convinced that it was rebuildable. Call it faith.
I had a couple of down moments. First, when taking the oil cooler fittings from the crankcase, a bit of water came out. There was also some water under the starter freewheel and in the primary case. The fire was doused by the firemen when they arrived and the bike was stood a week outdoors waiting for the insurance expert to come, before we could bring it home. No rust to be seen on the steel bits, notably the bearings. The synthetic cage on the left hand layshaft bearing has suffered from the heat. The engine can be turned over by hand, albeit with a bit of initial difficulty.
The clutch discs were well and truly stuck together. It was whilst trying the bike after having taken off the DAM kit because of a sticking clutch, suspecting insufficient lift, that I was hit.
I've been going from a half full to a half empty morale situation regularly with this project.
The more exposed and thin alloy parts have suffered, cam cover and sprocket cover, but not the main castings.
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The final decision on whether to rebuild it or move on would need opening the engine. Yesterday, a big step was taken when my son Matthieu dropped in for tea and to give a hand taking the engine out. An overhead winch in the garage is a big help with these lumps.

The mixture of burnt oil and rubber clings to everything. Some people love black engines.

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As soon as the engine was out, I whipped off the cam cover. I was relieved to find that all was okay. Just some cooked oil and molten rubber.
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I'll open this engine next week for a final diagnosis. I expect to find some water in the bores, we'll see.

Paul
 
Gerald said:
Fingers crossed that you don't find any expensive surprises when you open up the engine.

Gerald
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Thanks Gerald.
The insurance paid about what the machine cost me including purchase price, so technically, I could afford to rebuild it.
But will I have the courage and energy if extensive work is needed?
Paul
 
Took the Corsa out - as I hadnt ridden it for a few weeks - the weather was threatening but got to the garage and filled the tank up - decided to take the longish way home as I am coming into the village I see my MV mate at the pub so stopped for a pint - it was always going to rain at some point as the skies were black as coal - so slipped a pint down and it starts to piss down - jumped on the bike raced back home BUT as I entered our road she conked out - schoolboy error didn’t turn the fuel
On - it’s pissing down - so ended up pushing the last 100yds as those who have RGS bikes should know it’s takes minutes to get the fuel through / DOH soaked again !
 
Sir Sidney Ruffdiamond said:
Took the Corsa out - as I hadnt ridden it for a few weeks - the weather was threatening but got to the garage and filled the tank up - decided to take the longish way home as I am coming into the village I see my MV mate at the pub so stopped for a pint - it was always going to rain at some point as the skies were black as coal - so slipped a pint down and it starts to piss down - jumped on the bike raced back home BUT as I entered our road she conked out - schoolboy error didn’t turn the fuel
On - it’s pissing down - so ended up pushing the last 100yds as those who have RGS bikes should know it’s takes minutes to get the fuel through / DOH soaked again !
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The head is off the 3C.
The cam chain tensioner wheel has melted. I expected that, I just hope that the molten material hasn't got into the center main bearings. The tensioner blade itself is fine.
Both cam wheels were molten on my SFC when we opened that engine but that bike got a lot hotter than this one, there were a couple of bikes on top of it to keep the heat in.
The breather cover had molten partially as had of course its tube. That communicates with the primary drive and explains the little bit of water I found in there.
The billet intake stubs are fine though of course the O rings have molten.
Cooked oil is very sticky so two of the cam blocks were very tight on the cams but nothing to worry about. Two of the valve buckets are also stuck in the head but nothing that heat, lube and patience won't get around.
More worrying was that the left hand intake valve was stuck open. Water had obviously got into the intakes, the end of the guides and the valve stems are rusty.
All of the nuts, both the ones on the long studs and on the short ones on the cam blocks were undone by hand. Talk of differing expansion rates of metals.
The head came off more or less easily. The front cam chain guide has disappeared and bits of molten plastic can be seen down the cam chain tunnel.
The nuts came off easily but the studs are still solid in the head and crankcase.
Bores are fine as are the piston tops. The rust on top of the left hand piston is a deposit left by a bit of water, the piston itself is okay apparently. Liners don't appear to have moved, I didn't expect them to.
So far, so good.
I'll probably get the cylinder block off tomorrow.
For the moment, the main problem, apart from a major clean up, is the rusty valve stems but I expect the rust to be very superficial and the valves useable. Tolerances are close and it wouldn't take much to stick a valve. We'll see, on verra.
Paul
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After 10 years of ownership decided to rewire the SF1, pulled all the wiring off and then seemed like not that much more to pull everything off and get the frame repainted and all the other bits tidied up. Most things just need a clean but I think the rear shocks have had their day.

There will be a bit of engine work to sort out oil leaks and check the bores and piston.

There will most definitely be questions on the technical thread!


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The cylinder block on the 3C came off easily.
Pistons and bores check out ok, don't base an opinion on the photos. What looks like a score mark on the right hand piston is simply a bit without treacle. No score marks.
The rings are stuck in the pistons due to that treacle like burnt oil. They'll be renewed. Gudgeon pins slide nicely in the little ends.
No rust visible down below on the crank.
So far, so good.
I spent half an hour clearing the work bench which had become an "I'll put it there until I find a better place" sort of place. I now need to hoist the bottom end unto the bench without doing my back in or dropping the lump on the floor or on my feet. One is already broken.

Question time, there'll be many more:
- what is the recommended method for cleaning pistons? They're as new, only 3000 km on them. Parts of the tops are soot free.
- what about cleaning the cases? Locally, everybody says vapour blasting but Keith Nairn advised against it? Why? I need to phone him when the engine is apart. There's a company locally does aqua blasting. High pressure water. They do work for the aero industry. I need to phone them as well.

Paul

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  • Wow
Reactions: Jo
Blasting cases always is a gamble- it’s the cleaning them after and the blast medium can penetrate the alloy.
Chemical cleaning might be better, just depends on what will remove the black. I have scrubbed pistons with a Scotchbrite pad, might be an idea to pre soak them in petrol/ solvent , you might try an Ultrasonic cleaner after you get the worst off. I have used a steam cleaner in The past, very effective. Best of luck .
 
Exmoor beast said:
Blasting cases always is a gamble- it’s the cleaning them after and the blast medium can penetrate the alloy.
Chemical cleaning might be better, just depends on what will remove the black. I have scrubbed pistons with a Scotchbrite pad, might be an idea to pre soak them in petrol/ solvent , you might try an Ultrasonic cleaner after you get the worst off. I have used a steam cleaner in The past, very effective. Best of luck .
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Thanks, I had thought of steam. Or very hot water and then the ultra sonic bath.
Paul
 
A little carbon residue on the piston crowns is no big deal. It'll reform in no time after the engine is put to use again anyway. Wash the pistons in solvent to remove the rust and grime, remove loose carbon, free up the rings and away you go. The rings need to stand up to a lot more heat when the engine's running than what they were subjected to while the bike burned.

If the cases need to be blasted, blast only the outsides. Rinse out the internal grime and leave it at that. I've used glass, soda and the new-fangled vapour blasting processes and have never had an issue. Case blasting is only as good as the cleansing process afterwards, this takes a lot longer than the actual blasting. Fuck that up, the engine will be fucked soon after...

piet
 
I’ve just remembered- I used a stainless steel scourer ( looks like a ball of swarf ) on my crankcases- removes staining and oxide but without marking the cases Or losing definition. I Scrubbed mine in a citrus degreasing solution- I think that would work on your smoked cases. Also used a stainless wire brush.
 
Thanks for your comments.
I did my S cases many moons ago with wire wool and acetone.

What solvent would you recommend on the pistons? I've used a rag and acetone but that treacle is really stubborn.

I forgot to ask, while I'm at it. How do you get those gudgeon pin circlips, the ones without a tang to grab them by, in and out without scouring the piston? I'm not very good at that. :)

Paul
 
Paul Marx said:
Thanks for your comments.
I did my S cases many moons ago with wire wool and acetone.

What solvent would you recommend on the pistons? I've used a rag and acetone but that treacle is really stubborn.

I forgot to ask, while I'm at it. How do you get those gudgeon pin circlips, the ones without a tang to grab them by, in and out without scouring the piston? I'm not very good at that. :)

Paul
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have a look at the 'Ardrox' range of chemical baths (used extensively in the aircraft trade). Quite often termed as a de-carboniser it's pretty effective on just about any grunge. It would definitely remove most of the contaminents.
 
Paul Marx said:
Thanks for your comments.
I did my S cases many moons ago with wire wool and acetone.

What solvent would you recommend on the pistons? I've used a rag and acetone but that treacle is really stubborn.

I forgot to ask, while I'm at it. How do you get those gudgeon pin circlips, the ones without a tang to grab them by, in and out without scouring the piston? I'm not very good at that. :)

Paul
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I think you may have to soak the pistons a let the solvent do its work, petrol, WD40, acetone, vinegar, brake fluid,Diesel, oven cleaner ( anything caustic avoid!) gasket softener.
Years ago my Mum cleaned my Montjuic carbs in a pressure cooker ( on a skillet) with DAZ- I’ve also used a Karcher steamer to losen stuff. Trial and error. Gudgeon pin circling I use Short series Snap-on pin nose pliers but you can roll them out with a pointed pick.
 
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