I have heard that the first white ones they produced even splitted in half at the seams if ethanol was present.
Problems with the seams is a known problem. I guess even if they got their glueing process sorted at some stage, and if people avoid these like illness, there may be old stocks of faulty ones available for long time, and even longer if first-in-first-out is not working for the stocks that is often the case. I don't know if there is any batch identifiers on them. I don't know what would be the results for durability if all of the stocks would be somehow properly tested against leaks, at least I have checked mine not to leak, at least when new and again shortly after, still ok after several years and fingers crossed.
These white ones have thin walls with glued seams, the earlier black ones have thick walls and mold in place. Now I don't remember if one black I sawed open was hollow or solid inside, but at least very thick walls.
I think in the US alcohol fuels may have higher content of methanol than usually in the Europe. In Finland petrols available everywhere are 98E5 (5% ethanol max.) and 95E10 (10% ethanol max.), this is defined in fuel standard EN228, the value is maximum, not minimum. I think the stuff should be according to DIN EN 228 in Germany.
The Finnish fuels are poison for carburettors. Then we have a so called distribution obligation that means some percent of the sold fuels must be renewable, 19,5% at the moment, but this does not violate the maximum limits in fuel grades, most of the renewable stuff goes to Diesel and other fuels. I think similar should apply in EU. I don't know if in Germany they add some protective additives to their fuel or if there is some other differences. I open the bowls once a year for used bikes and there is grey dust at the bottom of the float bowls, and at least some of this originates from the Aluminium. Gumming of the fuel is also a notable problem, I find often, green, yellow, or white gum inside carburettors, sometimes even solid as plastic. Very notable precautions are a must. Carburettors in cars may work a couple of years without bigger maintenance. Finnish fuels used to achieve very low levels of Sulphur. Suplhur is known to cause corrosion and was a notable issue in many places especially some decades ago. I have thought about going to the later anodized Dell'Orto carb bodies (darker grey colour) and black plastic bowls on some bikes.
I have not got any issues with the mixtures, and I did not noticed any difference on the AFR meter when the floats changed from black to white. I guess that the white floats probably have smaller volume achieving similar density, for example, they don't have the wings on the button shaped floats. The part number was not changed, which to my understanding should mean a replacement on Dell'Orto, but this does not itself prove anything. I'm not stating for sure they are like this without studying them further, but I suggest some people should check again the laws of the physics.
In Finland we generally use 98E5 with valve guard on these Laverdas, except some rare ones confirmed not to need the valve guard. If some rare engines need over 100 RON fuel, then we lower the compression and use again 98E5. In Finland the standard pistons last normally around 300 000 kilometers in these big Massimo era twins and triples, not necessary in SFC spec engines, and I don't necessary suggest this result for all aftermarket pistons e.g. short skirt racing pistons. Valve train components also normally use to last n x 100 000 kilometres. This is how it has been normally last several decades.
People read such, strange answers, when reading this site such pistons need to be replaced after every 50 000 kilometres and valve seats are sink out of the adjustment range after every 80 000 kilometers.
We don't have many of the strange piston, combustion chamber, and valve train problems reported then and then on this forum.
Using lower octane rating fuel than designed is generally known to sensitize engines to these failure modes especially if something else fails.
As a general rule of thumb, in engines there should be safety margin designed-in for one fault at once, not for all of them, and not for two at once. Lower octane rating fuel also causes lower engine output.
Retarding ignition is generally known to increase heat load for exhaust valves, sensitizing them for heat problems especially if paired with other faults.
I suggest to read engine building books, one good one in English and well available is A. Graham Bell's Four-Stroke Performance tuning. Much of the content in the book is based on scientifically or other way well verified information. I seriously suggest to have a second thought for this "out of the box" thinking.
If some day there will not be 98 RON available anymore in Finland, I think we will lower the compressions mostly by changing pistons, and then we do the same again with somewhat lower engine output.
Well, I can say that I genuinely think that there very likely will be even more strange answers especially for this one, and I already know the formats of them - take popcorn and more beer for reading further replies.
And what, no proper output on a Laverda engine...
-Jouni
