laverda lesmo


New member
Hi any thoughts on this I believe verry rare laverda two stroke 125  looks in pretty good condition any one know much about these are there many in the uk ebay item
A great little bike when they are going,easilly as good as an Italian buuilt Yam TZR125 (not the dull thing we got here in UK)  I would hazard a guess and say that there are about six in England, I have ridden 50% of them.

The trouble is they are very fragile, I know the averda purists wont like me to say it, but they blow up a lot.A few years ago the then ILOC chairman, Ray Sheepwash, bought one from Toddy, is was very nice and ran very well for about 2,000 miles, then it stopped, the bike neded new piston and rings, plus cylinder, which Ray bought direct from the factory when he was in Breganze, duly fitted, he ran the bike for another thousand miles and then sold it on, the next owner blew it up shortly afterwards, and then bought some more one in bits) also from Phil, all three bikes are still in a shed near Castle Donnington airfield, having been sold on again to someone who never parts.none of them running.

I helped a lad in Essex with another, this was also a piston failed bike, we imported a complete LB125 engine unit (same except for an external electric driven water pump, and 5 not 6 speed) from Eduardo Dossena (former factory man, and a current member of Laverda Corse), this got the bike going well, and the lad had it sorted on a dyno, so carbuarationn was spot  on.This however did not stop the same thing happening  and that bike also was last seen in a shed in  Essex.Another was imported by my local dealer Bonanza, Big G said come and tell me what it is, so I did, it was a project and sold as such to a Surrey based person who attempted to get the bike going.A piston was needed and he found one, fitted it, and very shortly after it caught fire and melted pretty much everything.
There are a few others which I havent met.I do know where a piston and rings, plus a crank can be bought, but they wont be cheap, because there wont be any more, and no its not a dealer in Norfolk.
buyer beware.
Do you have any idea what the root cause of the piston problems was Clem? Possibly inadequate cooling?

There's not much to a two stroke, so you'd think if the bottom end was sound, then it wouldn't be too difficult to sort the business end out. Maybe a set of Yamaha (or othert Jap bike) pistons would be more robust.

Along with the Zanes, sounds like another Laverda best suited to an engine transplant from something that works. :-(
Good to know, I always fancied one, though mainly for the obscurity factor.
Steve B
The big problem with high performance '70s 2 strokes was that as the years passed tuners just cut bigger and bigger holes in the piston and cylinder walls until eventually the things were so floppy that by around '75 you had to replace a cylinder and piston for every race meet. Cylinder walls were just hardchromed alloy (no iron liner) to keep cost and weight down and improve thermal transfer, but that made the floppiness even worse.
When they started going to water cooling things slowly started to get a lot better, but even then it took a while before the top ends were still just disposable. I suspect the Laverda 125s probably went like stink because of radical port design, but wore out the piston and cylinder in no time. No big deal if spares are available and affordable, but if not, the bikes got very rare very fast...

The LB125 and the Lezmo was Laverda's own engine, but (of course) they may have "borrowed" from other makers where the design is concerned, some have said Husquvarna, but does anyone realy know? for sure they are not Zundapp engines, made by Zundapp,As in the LZ125 and LZ175, which were very rugged, long lasting reliable,and Laverda's best ever seller at something like 30,000 units! but again, maybe design parameters are within.I cant say why they fail early, it does not look like lubrication, but more like lean running, which Jody avoided by getting his dyno tuned at a two stroke specialist (BDK) with great care being taken to ensure stabilisation at constant throttle opening right across the twistgrips movement, as well as crusing and snap it wide,......but

I have seen in side the Chott (totally different motor, but still Laverda's own) and the problem with crankshaft and piston failure (in the Chott) is (IMHO) caused by the lack of a lubrication drain to one of the main bearings, one of them has the normal small puddle effect above the casting for the bearing with a drain hole to within, but the other has nothing, so it relies on mist, so there is there is only 50% of bearing fling, this (I think) is why the Chott fails.The 2TR seems to go on for a fair bit longer, and I have never seen inside one, so maybe this was changed? for the Lezmo, I would suspect the same might be the case, but I never owned one, so I never got have a realy good, in detail look.Piston failure on a two stroke can easilly be caused by a lack of lubrication, making the piston loook as if its been run too week, because the lube also does a lot of the cooling.

I would realy like a close look at an open 2TR if anyone is doing that, 2TR that is not Chott, the 2TR has only a single compression ring, whereas the Chott has two of the same, , also different ports, between the two, with the more radical ones in the more reliable engine, work that one out Steve B !!
as far as I understood it, the engine case of the LB came from Z?ndap, still, just the zylinder, piston and some other parts were Laverda's own design. no?
Other way round, Lothar.

The bottom end was Lavs' own design, they sourced the piston and barrel from Z?ndapp, hence the designation LB, Laverda Breganze, as opposed to LZ, Laverda Z?ndapp.

I knew there was something that was still from Z?ndap, just not what it was. Thanks, Piet  ;)

But this way, it should be fairly easy to source parts, as Z?ndapp - at least in Germany - KS125 zylinders and pistons schould be available - no?
well all the ones I have come across did, and if they were interchangeable with Zundapp then why has this shortage persisted.
'cos the Chinese are no longer producing them?

The entire Z?ndapp factory in Munich was disassembled, transported to China and re-built....

yeah, but there is a broad aftermarket supply chain for those things...

Mahle and Vertex are doing pistons for them:

so - no excuse to leave it in the shed ...  :D
I have noticed while looking like the same engines some of the engines on the lb 125s and custom lb 125s appear slightly diferent  to  the gs 125 lesmo being that they have one less cooling fin on the barrells only on close inspection do you notice this I wonder if this was a modification to help with overheating and seizing engines but as they were also water cooled would it make much difference.
Water cooled plus cooling fins on head and barrell like on an air cooled two stroke so why the problem with seizing engines if the oil ratio is set up right ???
Sorry lads, but the zylinder and piston of the Lesmo are not of z?ndapp. They were delivered by Gilardoni.
I owned one and I took it with me to the raduno in 2019 to Breganze. I booked a track session at the Adria raceway and had some fun with the bike. I over took two 750 (hard to believe but I did so) but I went out after five laps because it drove me crazy because of rough contact to the tarmac with the big exhaust in every right hand bend.
On the way back to Breganze the engine blow up and I came back by the automobile club.
I sold the bike as it was and the buyer diagnosed a broken water pump.
Now I own a LB Uno with the engine of the Lesmo (what is the most powerful 125 engine built by Laverda) which was started to build a Trofeo replica by the seller. When its finished I look forward to use it on the norrow roads of the Eifel and the Ardennes to hunt some big bikes 👹
The next 125 evolution by Laverda was the Navarro with the engine of the Aprilia 125 o_O Guess why? :unsure:

Clem, the TR and Chott not only have different pistons and ports, the cranks are different as well.
put some pictures on here, that would be nice :) There is a small pump for the oil. I disconnected this and mix it my self. This is much more safe. I have an Uno to and it has 8000 on the teller. It still runs good. I just bought it this year so not that much experience.. yet.. :)