yianne:
i missed your question
a 6/1 listeroid is a very simple piece of equipment, however there are those that are good, some that are garbage
and the majority fit somewhere between.
no manufacture is better than any other at this time, they all have issues which range from just irritating to down right
horrible to contend with.
the problem lies with who to believe, and who not to believe
a warning is warranted in this area, do not ever believe that these engine's are 100k hour engine's anyone telling you they
are is lieing or horribly uninformed, even though the original listers were said to be 100k hour engine's none of them made it anywhere that far without frequent minor and at least a few major overhauls. a good well prepared listeroid is good for maybe
7-10k hour running on veggie oils, that with frequent services, head removals to clear carbon and valve reseating.
they turn slow and have a pleasant rythimic thump, thump while running and look cool, old school with open spoked flywheels
which can be a liability too. expect to get about 1 kwatt/hr for each 1/8th gallon of fuel consumed running near full load
with much higher consumption at part and very low load.
a good 6/1 will make about 3kw electrical output in most area's, less if you are at high altitudes.
running the engine at or near full load will allow for best economy and the engine will likely run longer between decarbon and/or rebuilds.
as for the bits and pieces, the casting are rough, as cast in a back yard sand pit where they are born
the steel fuel lines fail as do the fuel tanks leak, valve guide geometry can be anything from barely adequate to horrible
which rapidly wears out valve guides, and they have rich history of idler gear failure due to poorly placed idler gear bolt
and their use of a poor quality cast iron that is wholey unsuitable for a cam idler gear,, bronze gears can help but there
is still the positioning issues to deal with. that issue has been resolved by the diy'er community with the use of offset idler
bolts or the use of a special offset bushing that repositions the idler gear between the crank drive gear and the cam gear.
i can go on and on, if you like
the reality is this, these engine's when they were available for between 699 and 999 bucks were a good buy, because at that price level one could spend some time and money to make them right, correcting the faults and getting them up to snuff.
however now that they are hard to find and the price is between 1500 and 2000 dollars, in my opinion that is just rediculous
because you will have much more invested before you get it right,,, there are far better options in my opinion.
a chinese engine, while noisier, runs faster, will compete very well in fuel economy if ran at or near full load will actually do better
than a lister/listeroid, will be more reliable, and is just a much better engine in design/fit and finish.
sadly they too have been banned, but the do come up on ebay and craigslist, and while their prices have appreciated they haven't gone up as much as the listeroids.
you can find a s195 watercooled changfa with electric start that will make an easy 12hp all day long at 2000rpm, can run direct drive at 1500 or 1800, and also can be turned down to around 1000rpm with reduced hp. these engines come up for around 750 bucks average. they are in everyway superior to any listeroid except for decible levels, the listeroid is fairly quiet the changfa is quite loud. the life expectancy is quite good with the changfa, i would expect at least 10k hour from one out of the crate, with only a cursory inspection done before the engine has been put in service.
i know of one such 195 that has been fitted with additional flywheel weight (about another 80lbs if i recall) that is running in the
650rpm range and it is a joy to be around,, much quieter in operation than it is at 1800 or 2000rpm
bob g