Mikuni

[sfcpiet]

what you are forgetting Lothar is that large bore carbs on a given engine of any type will leave you with low gas speed, at any given opening, the same motor at the same speed with a small bore carb will have high gas speed and that can be extremely beneficiial, too small (though) and it may strangle top end.

I was once told be a very knowledgable tuner who was doing one of multiple runs on TOG, that I bothered with a few years ago, that I might be better off with a 41mm single SU over the 3X32 Dells, he also said I realy should try 30's and even 28's.

remember the SU is a CV carb and the Dells have manual opened slides.
CLEM

A single carb on a Laverda triple may be fine for economy, but who the fuck rides one for that? It certainly wasn't built for it. Efficiency providing max performance, yes, economy, no. Top end would definitely suffer with 28mm carbs, quite OK though if you're content with tootling around at 50mph.

But yes, bigger carbs are not without issues, especially if navigating in slow, heavy traffic. That's where cv carbs come in. Big enough for max performance at WOT, but able to meter decently at small throttle openings.

piet

 

[Paul Marx]

A single carb on a Laverda triple may be fine for economy, but who the fuck rides one for that? It certainly wasn't built for it. Efficiency providing max performance, yes, economy, no. Top end would definitely suffer with 28mm carbs, quite OK though if you're content with tootling around at 50mph.

But yes, bigger carbs are not without issues, especially if navigating in slow, heavy traffic. That's where cv carbs come in. Big enough for max performance at WOT, but able to meter decently at small throttle openings.

piet

Laverda triples weren't expected to last half a century either, so why not a single carb?
Paul

 

[Laverdalothar]

what you are forgetting Lothar is that large bore carbs on a given engine of any type will leave you with low gas speed, at any given opening, the same motor at the same speed with a small bore carb will have high gas speed and that can be extremely beneficiial, too small (though) and it may strangle top end.

I was once told be a very knowledgable tuner who was doing one of multiple runs on TOG, that I bothered with a few years ago, that I might be better off with a 41mm single SU over the 3X32 Dells, he also said I realy should try 30's and even 28's.

remember the SU is a CV carb and the Dells have manual opened slides.
CLEM

Hi Clem, as Piet already mentioned, I was talking about max. performance not about low end throttle reaction (or economic efficiency). When I started my journey to improve the performance of my Jota, the focus was performance, if possible without sacrificing low end torque. My bike puts out 83Nm at the rear wheel at 3.500 revs, 110Nm (engine, 100 at rear wheel) max and 110 HP (engine, 100HP at rear wheel) at Top. Mission completed for a street bike, I'd say. The 1000 SFC (with an unmodified engine...) produced 105 HP (10 more than with the 32mm carbs it came with), had a widely improved torque curve and max torque was about 100Nm (roughly also 10 more than factory). Meanwhile the engine has been upgraded a bit but I haven't had it on the dyno ever since.

Further to that, be sure, I spent an awful lot of time to get the bigger carbs right. There are tons of material and additional stuff to get the Keihins to work better, like other accerlation pumps, PowerBlades and other stuff. I followed that route f.e. and separated the inlet channel in two parts to improve the throttle reaction in low speed. Works quite well...

Then, if you look into the difference between a Keihin or Mikuni flat-slide carb against a round slide Dell'Orto, there are SO many improvements over the Dell'Orto, you wouldn't imagine... beginning with the 32mm Dell'Ortos getting wider (38mm) where the gas gets vaporised, which in itself is clear nonsense: lowest speed at the point where the highest speed should be. Then the higher friction of the round slide compared to - partly - roller guided flat slides. The number of edges and corners inside a Dell'Orto are so much higher and causes inefficiency (in terms of power output compared to gas consumption) and so on and so on. Not to talk about gimmicks like "HyperSnoozle" on the Mikunis...

Just putting 36mm Carbs on a 32 mm head or - in my case - 39-40mm Carbs on a 36mm head makes less sense, I agree. But if you tapper the inlet from the carb size to the 36mm, use 1200ccm high compression pistons, an exhaust system that actually supports the breathing of the engine and many, many more modification, all of a sudden a bike that had roughly 70 HP and consumed 9 Liters/100km produces 110HP and consumes only about 6 Liters. That is my measurement of efficiency: not only reducing the consumption but at the same time increasing the Power output and torque while maintaining/controlling the heat of the engine.

Each to their own, please. If someone wants to put a single carb on a triple - hey - why not? Will it be the most performing Laverda ever built? For sure not. But if that is not the focus but low gas consumption (while giving up on some Power and torque) - why not?

That's all said for engines that are not charged. On a charged engine, that is a totally different story. But who (besides Malcome) turbo-charges Laverdas?

 

[Paul Marx]

To each his own.
For some, what matters is the yearly distance travelled which has little to do with performance and a lot do do with motorcycling.
Paul

 

[CLEMTOG]

a few years ago I was organsising a day at Bruntingthorpe proving ground, this would have taken the form of several "top speed runs" using two way calculations and a mobile dyno, none of the reprobates that talk about power ,torque and top speed were prepared to put there bikes where there big mouths are and so the day floundered, IIRC, there was a need for 40 or so attendees on the day to break even, I didnt even get 8! and that included me.
CLEM

 

[piranha-bro2]

Laverda triples weren't expected to last half a century either, so why not a single carb?
Paul

Says who? I don't recall ever reading anything from Moto Laverda stating that 'the life expectancy of this motorcycle is x number of years'. They just built them and people rode and repaired them.

Absurd hypothesis Paul.

 

[piranha-bro2]

To each his own.
For some, what matters is the yearly distance travelled which has little to do with performance and a lot do do with motorcycling.
Paul

Funny 'bout that - what you're saying is there's no hard and fast rule for what people should or shouldn't do to or with their motorcycles. So things like discussing the pros of points and numbers of carburettors is fine, as long as it's analytical and not proscriptive (ie I'm right and you're wrong).

 

[sfcpiet]

Laverda triples weren't expected to last half a century either, so why not a single carb?
Paul

No modern-day product is expected to last half a century any more.

I don't see any connection between life expectancy and the number of carbs a bike has though... Laverdas have largely survived for a number of reasons.

The main reason is, the Laverda clientele has always been pretty nuts about their bikes and many of them quickly became very loyal to the marque.

The Laverda triples were designed to compete on a certain market, which they did fairly sucessfully for such a small manufacturer. Of course Massimo wanted us to buy a new bike every few years, he wasn't building them just for fun. But he also didn't build automatic obsoleteness into his products, as many other manufacturers did (either knowingly or un-knowingly?). Most components that Laverda actually manufactured can be almost indefinitely re-built in the event of failure. Even the high-quality stuff that was sourced elsewhere can often be salvaged after a mishap, unlike much modern stuff that can only be trashed. Then there is the extremely long period that spares were kept in stock. Finding certain odds and sods for a Honda 750/4 was already a nightmare in the 1980s! eg, I can't remember OE master cylinder repair kits ever being offered from the major japanese makers back in the day, it was later up to the aftermarket to cater for that sort of stuff. Dealers for the Big 4 were ever reluctant to order carb parts, the procedure was time-consuming to order, recieve the parts and inform the customer. The small number of different models and the large number of shared components made it a lot easier for Laverda dealers to keep a far more comprehensive stock of spares. Of course, this was all pre-eMail/computer days, something we have by now taken for granted and which makes so many things so much easier.

Then there is the uniqueness of these bikes that has kept them alive for so long. Personally, I can't really find much difference between riding a Honda, Suzuki, Yamaha or Kawasaki large capacity 4-cylinder bike of any given era. They were all created to compete in the same market segment, they behave alike and offer much the same in performance, handling etc. It is there that marques such as Laverda, Ducati, Guzzi etc stand out and offer a truely different and unique riding experience (we're still in the '70-'80s here). Things changed dramatically later, with even the most exotic marques going bland in order to compete in the sales battle.

To each his own.
For some, what matters is the yearly distance travelled which has little to do with performance and a lot do do with motorcycling.
Paul

Motorcycling has always been closely connected with performance. Competition arose the moment when 2 bikers first met on some dusty rural road at the end of the 19th century... Performance has always been a defining characteristic for marketing, save maybe for purely commuter vehicles. But even then, an additional pony or 2 can be the deciding factor if you need to haul half a ton of bricks through the vietnamese jungle on a step-thru.

Paul, you could probaby spool off your annual mileage on a Mobylette, just as on your Laverdas. But I don't think even you could be attracted to one of those contraptions.

piet

 

[Paul Marx]

No modern-day product is expected to last half a century any more.

I don't see any connection between life expectancy and the number of carbs a bike has though... Laverdas have largely survived for a number of reasons.

The main reason is, the Laverda clientele has always been pretty nuts about their bikes and many of them quickly became very loyal to the marque.

The Laverda triples were designed to compete on a certain market, which they did fairly sucessfully for such a small manufacturer. Of course Massimo wanted us to buy a new bike every few years, he wasn't building them just for fun. But he also didn't build automatic obsoleteness into his products, as many other manufacturers did (either knowingly or un-knowingly?). Most components that Laverda actually manufactured can be almost indefinitely re-built in the event of failure. Even the high-quality stuff that was sourced elsewhere can often be salvaged after a mishap, unlike much modern stuff that can only be trashed. Then there is the extremely long period that spares were kept in stock. Finding certain odds and sods for a Honda 750/4 was already a nightmare in the 1980s! eg, I can't remember OE master cylinder repair kits ever being offered from the major japanese makers back in the day, it was later up to the aftermarket to cater for that sort of stuff. Dealers for the Big 4 were ever reluctant to order carb parts, the procedure was time-consuming to order, recieve the parts and inform the customer. The small number of different models and the large number of shared components made it a lot easier for Laverda dealers to keep a far more comprehensive stock of spares. Of course, this was all pre-eMail/computer days, something we have by now taken for granted and which makes so many things so much easier.

Then there is the uniqueness of these bikes that has kept them alive for so long. Personally, I can't really find much difference between riding a Honda, Suzuki, Yamaha or Kawasaki large capacity 4-cylinder bike of any given era. They were all created to compete in the same market segment, they behave alike and offer much the same in performance, handling etc. It is there that marques such as Laverda, Ducati, Guzzi etc stand out and offer a truely different and unique riding experience (we're still in the '70-'80s here). Things changed dramatically later, with even the most exotic marques going bland in order to compete in the sales battle.


Motorcycling has always been closely connected with performance. Competition arose the moment when 2 bikers first met on some dusty rural road at the end of the 19th century... Performance has always been a defining characteristic for marketing, save maybe for purely commuter vehicles. But even then, an additional pony or 2 can be the deciding factor if you need to haul half a ton of bricks through the vietnamese jungle on a step-thru.

Paul, you could probaby spool off your annual mileage on a Mobylette, just as on your Laverdas. But I don't think even you could be attracted to one of those contraptions.

piet

My first personal motorised two wheeler was a mobylette. A simple contraption quite capable of going around the world. Who knows how I might finish?
Racing improves and sells the breed, which is why I bought a Laverda triple when I was 26. Now I'm nearly 70, I don't relate to performance but rideability.
On today's roads, performance isn't a criteria for selling the vast majority of motorcycles. Harleys, BMW, Guzzis to name but a few. And tomorrow is electric.
Paul

 

[Paul Marx]

Says who? I don't recall ever reading anything from Moto Laverda stating that 'the life expectancy of this motorcycle is x number of years'. They just built them and people rode and repaired them.

Absurd hypothesis Paul.

Laverda disappeared before going any further in the development of a large scale industrial product, which was the way the company was going.
V6, V4, V2 anybody?
So yes, some people rode them and repaired them. Some still do.
Paul

 

[sfcpiet]

My first personal motorised two wheeler was a mobylette. A simple contraption quite capable of going around the world. Who knows how I might finish?
Racing improves and sells the breed, which is why I bought a Laverda triple when I was 26. Now I'm nearly 70, I don't relate to performance but rideability.
On today's roads, performance isn't a criteria for selling the vast majority of motorcycles. Harleys, BMW, Guzzis to name but a few. And tomorrow is electric.
Paul

Not really, Paul

The Beemer GS, in itself a quite capable bike in its' original form (if you're into that sort of thing...) went from 50hp to 149hp in its current form. And a major part of their clientele today are grey-haired old farts with excessive cash, much like ourselves.

150 ponies in a chook chaser? WTF? Of course, the current edition has totally eclipsed the original, defeating the original concept of a light, easily manouverable road bike that could safely tackle a gravel road now and then. The buggers are so big and heavy (and expensive in the event of a topple) that they rarely see an un-paved road, let alone the Via del Sale... google it if you haven't heard of it! Instead they're outfitted with 300 litre hard baggage, crash bars and lighting equipment fit for a trans-globe expedition, just for a tootle down to the local ice cream parlor.

The biking world has certainly changed from what you and I grew up in. Just as in many sectors, the bike industry has managed to dictate what we "need" and Joe Public has willingly lapped it all up, clamouring for more. Common sense and self-restrainment have been chucked overboard long ago. Pretending and showing off seem to be a major part of todays' society and bikers are no exception, see Beemer GS riders (my pet hate, cruisers come a very close 2nd. ) . Only, there are rarely any flies and bugs on their top-of-the-line €5000 expedition clothing. The whole thing has gone far further from just having fun within your means to bragging and pretending. Having cash to burn seems to help, despite all the moaning over how expensive everything has become. Fucking insane imho.

Harley and Guzzi have also taken measures to keep up in the performance stakes. They are gradually binning their air-cooled offerings because these cannot keep up under todays' stringent regulations.

Going to take quite some time before electric takes over completely, commuter cars and bikes are a different kettle of fish than recreational toys. As long as we have the means to pay for them, the industry will supply.

piet

 

[Jo]

Complety agree - we seem to have a similar enemy image. The current GS models are SUVs on two wheels, just like their fat 4-wheeled counterparts, which I consider as pus-blisters. Most embarrassing for me are the current SUV coupes - these things look to me like a 300kg person in a thong. This fatter and bigger 'evolution' is definitely a development that completely disgusts me.

 

[sfcpiet]

Complety agree - we seem to have a similar enemy image. The current GS models are SUVs on two wheels, just like their fat 4-wheeled counterparts, which I consider as pus-blisters. Most embarrassing for me are the current SUV coupes - these things look to me like a 300kg person in a thong. This fatter and bigger 'evolution' is definitely a development that completely disgusts me.

Simply stupid vehicles. Interior is too small for the arguement "we need a big car", exterior is too big for a daily driver in todays inner-city conditions. Only good for bragging rights, and possibly to one-up the Jones's down the road.

I'd propose to mandate that every owner of enormous, mostly needless SUVs must produce proof of ownership of a trailer of at least 2000kg capacity upon registration and that these stupid things have a visible, permanently attached towing hitch, their one and only valid reason for existance. Reckon about 85% of these things would disappear almost overnight, can't have snobbish Karens driving around with an ugly towing hitch, can we...

piet

 

[murphus]

You should try driving around the Midwest in the good old US of A, where suburban moms apparently believe they need a diesel-powered 4-door super-duty 4x4 truck for grocery getting. Fucking things are so huge they won't fit a standard parking spot, but they're everywhere. They're ponderous beasts and actually a drag to drive. I don't get it. At all. As to your mandate idea, Piet, I'd like to at least see weight penalty taxes. These 6,000lb-plus beasts tear up roads, but there's no penalty, so to speak, for doing so.

 

[sfcpiet]

You should try driving around the Midwest in the good old US of A, where suburban moms apparently believe they need a diesel-powered 4-door super-duty 4x4 truck for grocery getting. Fucking things are so huge they won't fit a standard parking spot, but they're everywhere. They're ponderous beasts and actually a drag to drive. I don't get it. At all. As to your mandate idea, Piet, I'd like to at least see weight penalty taxes. These 6,000lb-plus beasts tear up roads, but there's no penalty, so to speak, for doing so.

I intended to mention these, but thought that would extend my rant too far.

99% are simply status symbols... "Hey, look at how much money I can burn, and I don't give a flying fuck about anyone or anything!", which one could also interpret as "Hey, I'm one helluva dumb motherfucker!"

Weight-based taxation has found its way into various political discussions here in Europe, especially in France it seems. Many german communities are considering hiking park fees for these monsters. Imho, these can't be high enough.

piet

 

[chrisk]

"Hey, I'm one helluva dumb motherfucker!"

Oops, I resemble that remark. It’s only a ‘smallish’ 7.3litre diesel swilling motherfucker.

Although, it’s actually a healthy option for me. When I go to the shops I have to park miles away because I can’t get a parking spot nearby and have to walk.

 

[motoddrob]

I have a GS1000 BM, it's an old airhead with single disc and 21" front wheel and sees more dirt roads than bitumen. Also have a big fucken Land Cruiser and it has a tow hitch and I have a trailer. It also sees dirt roads and takes me to remote beaches.
Does that make me a dumb mother fucker but I do live in the bush between 1000s hectares of Forrest with tracks going everywhere and the south coast with remote beaches where only 4wd can access.
I see big GS Bms cruise through town complete with the tourtek catalogue and they never get off the bitumen.
But then again I wouldn't want to take the fat ugly pigs off road anyway.

 

[CDHE]

Need to refocus this thread for just a moment......Mikunis are mounted with plenty of space by removing insulators and shortening spigots by about 5mm. Not quite enough room to install the little conical K&N filters I purchased along with the carbs. It has been suggested that I consider using the stock sheet metal system. Unsure about going about finding rubber boots that would make the connection. Don't have the stock ones to check fit. Any thoughts? Thanks.

 

[chrisk]

Need to refocus this thread for just a moment......Mikunis are mounted with plenty of space by removing insulators and shortening spigots by about 5mm. Not quite enough room to install the little conical K&N filters I purchased along with the carbs. It has been suggested that I consider using the stock sheet metal system. Unsure about going about finding rubber boots that would make the connection. Don't have the stock ones to check fit. Any thoughts? Thanks.

Yep, fit trumpets.

 

[Tippie]

You will have to provide a good seal on the intake stubs, as the o-rings are in the insulators originally.
My FCR Keihins connect from their original short inlet stub things to the standard airbox via the original rubbers, very neat and effective. Standard airboxes come up fairly often second hand, and the rubbers are available. It is most likely possible.