---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Tue 03/07/06: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:06 AM - Re: RotaxEngines-List Digest: Hard Starting (Martin Hone) 2. 07:30 AM - Re: 912uls battery? (John & Paddy Wigney) 3. 09:58 AM - 914 operations with wastegate closed () ________________________________ Message 1 _____________________________________ Time: 01:06:29 AM PST US From: "Martin Hone" Subject: RotaxEngines-List: RE: RotaxEngines-List Digest: Hard Starting --> RotaxEngines-List message posted by: "Martin Hone" Re Hard Starting - Over the 11 years and 500 hours I had my Rotax 912, the most I ever got out of a battery was 2 years. I was using Harley 19 ah mostly, even tried a 30 ah out of the Big Twin model but the 912 just seemed to have an appetite for batteries. In contrast, the Odyssey 680 in my Lycoming -powered RV has been flawless for the past 2 years and 200 hours. In starting the 912 from cold, it is imperative that the throttle is fully closed and the 'choke' ( actually a separate starting circuit ) is activated. This is typical of CV or Constant Velocity-type carbs that don't have an accelerator pump. Because the 912 is a fairly cold-blooded beast and runs quite lean, I sometimes found that it was helpful for starting to unhook the float bowls with the fuel selector 'on' and let them fill up a bit higher before clipping them back together. Those that have any experience with the 2-strokes may recall that this, or blowing in the overflow tube to achieve the same thing, would make a big difference to ease of starting. Definitely don't do it if the engine is already warm.... Another bit of advise is to make sure that the spark plug gaps are set to the factory specs. and not a fraction more. Regarding oils - Mobil One motorcycle oil can be had in both 15W-50 and 20W-50 grades, while the automotive series is much thinner - 5W-30 etc - definitely not suitable for the 912's gearbox. FWIW, Martin in Oz ________________________________ Message 2 _____________________________________ Time: 07:30:29 AM PST US From: John & Paddy Wigney Subject: RotaxEngines-List: Re: 912uls battery? FWIW, I have used an Odyssey PC545 12AH battery from day 1. It has always cranked the engine in cold conditions and the engine almost always fires within 2 or 3 blades. "Cold" for me in North Carolina usually means somewhere between 35-45 degF. I now have 1 year on my second battery and I changed the first battery after 385 hours and 4 years when the starts were becoming only a little sluggish. The battery is mounted on the firewall so that the voltage drop is low. Cold cranking amps = 545 amps for 5 seconds, weight = 11 lbs. Also note that my fuel is 100LL, my oil is Valvoline Durablend 10W-40 and I have a Whirlwind Series 100 constant speed prop which weighs ~ 9 lbs. I change my plugs at 100 hours and check/reset the gaps at 50 hours. My cold start routine is :- 1. Close throttle and choke. 2. Crank engine. 3. Pull choke knob. 4. Adjust choke when engine fires to obtain 2,000 to 2,500 rpm. 5. As engine warms up, bleed off the choke and add throttle to maintain 2,500 rpm. Cheers, John Wigney N262WF, Europa monowheel XS, 912ULS with original starter ________________________________ Message 3 _____________________________________ Time: 09:58:01 AM PST US Subject: RotaxEngines-List: 914 operations with wastegate closed From: --> RotaxEngines-List message posted by: My Rotax 914 operators manual speaks of take offs with the wastegate in the closed position and switch rendering the servo inoperative as per some designated regulation that I am unfamilar with. What are the downsides to operating a 914 with wastegate complete closed and the pilot regulating boost pressure with throttle? What are the up sides to operating a 914 with wastegate complete closed and the pilot regulating boost pressure with throttle? Is anyone out there doing this? Thx. Ron Parigoris