Airborne Magazine - Issue #249 | Page 55

The mount works by sandwiching a front and rear rubber disc on either side of the rear mounting frame with a washer on the back and the engine stand-off at the front. These rubbers act as mini shock absorbers and dampen the vibrations produced by the engine. In operation the mount works very well. The vibration levels transmitted into the airframe are very low. Initially at certain low to midrange RPM the engine shook a little but it was nothing to be concerned about and after running in and proper adjustment of the needles, the low-end vibration was all but eliminated. The engine is a single ring design and peering into the exhaust port the cross hatching on the cylinder wall looked good and the edge of the transfer ports looked clean and well machined. The cylinder head is a single cast unit with larger fins on the lower exhaust side of the head to help draw away heat from around the exhaust port. The casting of both the head and body is well made and follows in the fashion of DLE’s 55 designs. The carburettor is a Walbro look alike made by DLE and features a throttle linkage arm made for an easy servo linkage setup (finally!) while the choke arm is still the small Walbro original type. Tuning of the needles from factory was slightly rich but acceptable for initial break in and they weren’t overly sensitive in adjustment, which was good. One point to note with the new throttle arm design is that at higher than idle throttle position, the arm starts to cover the high and low mixture adjustment needles. Even at idle the linkage to the throttle arm is still slightly in the way and I see this as a good thing in the way that it forces the user to make adjustments to the engine with the engine off. Great as far as I’m concerned because if you read the minutes of the MAAA monthly meetings you’ll notice so many modellers being injured by rotating props. And a 26-inch prop swinging around is a big hazard. The supplied muffler is a little on the noisy side (sorry I don’t own a db. meter) and DLE have tried to keep the volume large whilst still trying to keep the muffler practical, so they opted for a slanted front to help keep it in various cowl shapes. The exhaust stub is short and a Teflon extension tube is supplied with a clip to get the hot gases outside the cowl. On the top of the muffler is a welded in nipple for those that wish to add smoke to their models. The ignition supplied looks identical to other DLE ignitions, but is marked on the rear that it is specifically for the DLE-85. A nice feature of the ignition is that it can operate on any voltage between 4.8v and 8.4v, so a small two cell LiPo can be used if preferred. The wiring harness also includes a lead for connecting an optional tachometer if you want to. The DLE manual says to run the engine on 30:1 fuel/oil mix and I ran this engine at that ratio using BP Ultimate unleaded fuel and Mobile 2T fully synthetic two stroke oil. After burning three litres of fuel the needles have been leaned from the factory set- Airborne 55