by Guest » Mon Mar 07, 2005 3:32 pm
Hi Tyler, I think you understand what I meant. If not then here's a long winded explanation of my opinion. The JPX is a great engine and performance with them on the single seater is super. They are smooth running reliable engines. My point however was the JPX was just a bit heavier than what many (Americans) considered to be "ideal". Ultraflight thought they had a winner in the WAM-342 as it had a HP close to the JPX while weighing nearly the same as the Rotax 185. As a consequence of the problems experienced with the 342 Ultraflight resorted to the JPX and KFM for the Lazair II and emerging "Elite" prototype model.
As a consequence of the added weight, power, and performance of the JPX and KFM engines the airframe of the Series 3 was subsequently upgraded. The "Elite" was born. These modifications pushed the Elite up to a weight close to, or in excess of, the 254lb FAA 103 weight limit. Ultraflight, unlike its major competitors tried to keep the Lazair (single) a truely Part 103 compliant Ultralight (for American sales). Usage of the JPX engines (in America) along with necessary airframe upgrades limited the amount of accessories (like the full enclosure) one could use and remain truely legal. The Series 3EC even with Rotax 185s was "danger close" in exceeding the 254lbs limitation.
As you mentioned the Lazair II has marginal performance with JPX's and we know the KFM's have outrageous fuel consumption. Were either of these engines "Perfect" all things considered... I'd say no but I guess Ultraflight did the best they could at that time.