Chez Has had a few mods done to soften his YZ off He has had us fit a heavier enduro type flywheel so its not as fierce and should vibrate less . The key to reliability and smoothness is a balance shaft but there are only two 2 stroke engines which have them fitted the Honda CRM 250 (as used in stickys black scoot) or in the Aprilia RS 125 (which is actualy a rotax manufactured engine)
The other thing with lambrettas with motorcycle engines fitted is that if you fit a motor that has 40 +HP you are never going to be able to utilise all the power , which is why if yopu have ever been on a ride with sticky you will not be able to keep up ! his engine the CRM has less than 40 hp as std I believe which allows him to give it some and utilise its full performance potential. This is also the case with the 125 Aprilia / Rotax motor this has around 32 hp deristricted and 35 ish when fitted witha Polini 155 kit we have one in one of our shop bikes and its absolutley perfect for the job. Have a look on website
http://www.lambrettainnovation.co.uk/vi ... d=197where you can see it finished .Is this a good spec or what 35 hp, 6 gears,and electric start and reliable thats what everybody would love in a lamby engine and its for sale !