---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Wed 07/22/15: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:52 AM - Re: 912 ULS Fuel Pressure (david park) 2. 10:39 AM - Re: 582 grey head ignition (blumax008@aol.com) 3. 07:54 PM - Re: 912 ULS Fuel Pressure (Richard Girard) ________________________________ Message 1 _____________________________________ Time: 04:52:14 AM PST US From: david park Subject: Re: RotaxEngines-List: 912 ULS Fuel Pressure I have exactly the same experience, this was after fitting the new mechanical pump which operates at a slightly higher pressure, it didn't happen before the new pump was fitted.? The drop in pressure does not effect the engine performance but am wary of switching the electric pump back on if required. Regards Dave Park G-LDVO On 21 Jul 2015, at 22:29, Carl wrote: > HI Stan > One year ago I had the same symptoms that you had. I believe this was caused by the fact that the electric pump has a slightly higher pressure than the engine pump and this causes the engine pump to stop pumping while the electric pump is "on." This stagnation of fuel in the engine pump during TO/Climb cause that fuel to vaporize and a momentary loss of pressure when the electric pump is turned "OFF". > I've moved my gascolator, filter and boost pump to the rear compartment and firesleeved all the lines. I also ran a return line to my right wing tank. Seam to have helped some but I still see the pressure drop and the occasional warning light when I turn the boost pump "OFF". Never affected the engine but always ready to reselect to boost pump. > After shutdown on a hot day burning auto fuel, put an ear close to the engine pump; bet you will hear the fuel boiling. > Carl > > ----- Original Message ----- > From: Stan Tew > To: rotaxengines-list@matronics.com > Sent: Monday, July 13, 2015 6:47 PM > Subject: RotaxEngines-List: 912 ULS Fuel Pressure > > My 912 ULS mounted in my Rans S7-S has 438 hr. I replaced the old style mechanical pump as recommended by Rotax. I have an electric fuel pump and fuel pressure gauge. I usually take off with the electric pump running in addition to the mechanical pump. When I level off to cruise I turn off the electric pump. My pressure usually is about 4.5 psi. Last week I was flying and noticed the EIS warning light and it identified my fuel pressure to be about 0.9 psi. I quickly turned on the electric pump. The pressure went to about 3.5 psi. I flew back and landed without incident. The engine never faltered. > > Any suggestion on how to test the mechanical pump? Any suggestion on what the problem might be? I have not had opportunity to remove the cowl to make any visual checks. > > Stan Tew > N29TD > > > href="http://www.matronics.com/Navigator?RotaxEngines-List">http://www.m atronics.com/Navigator?RotaxEngines-List > href="http://forums.matronics.com">http://forums.matronics.com > href="http://www.matronics.com/contribution">http://www.matronics.com/c > > > > ________________________________ Message 2 _____________________________________ Time: 10:39:19 AM PST US From: blumax008@aol.com Subject: Re: RotaxEngines-List: 582 grey head ignition Enough to go absolutely insane.... Tell me about it Bart. I've been flying two cycle UL's since '78. I thought I knew all the mysteries of the 2-cycle engine. Right. Had a carb leaking fuel badly on my Hornet. Changed it. The replacement leaked just as bad. Changed to a 3rd. carb...same thing. All three were rather old carbs that used Ethanol back when I couldn't get E-free. Finally, I took one (Bing 54) off my Trike that I knew worked okay and fitted it. Didn't leak. I consulted two old time 2-cycle operators: Beaver Borne in Reserve, LA and Rick Davis in Naples, FL. They too were at a loss. I took all carbs apart & found eroded Viton tips we're pretty sure was due to Ethanol & causing the Viton to not seal properly - and causing fuel overflow into float bowl and engine failure. Bottom line, don't use E fuel. Photo was taken in 2010 when I couldn't get any E-free fuel. blumax008@aol.com -----Original Message----- From: Bart Rond Sent: Tue, Jul 21, 2015 5:49 pm Subject: Re: RotaxEngines-List: 582 grey head ignition Hi Richard and Guy, Thanks for the tips, you were both right! So far I was able to track it down to either the generator or the wires to ignition box 2. Sunday we switched out the ign.box for a spare one and the problem stayed the same. I also measured the coils in the generator, the kill switches and the wires that connect them, no problem there. When I interchanged the connectors of the wires to the kill switches, the problem moved to the other switch. Today I mounted new connectors in the white and green wire between the generator and the e-box, no change, the engine still stopped with ign2 ON and ign1 OFF. Not all the time tough, but after a few minutes of taxiing!! Then I was sure I had it fixed, when I cut the white and green wire close to the generator housing and connected new wires instead. The engine kept running all the time on both ignitions!! So I cut the engine to put insulation on all connections and secure all wires with tie-ripps, and then the downer occurred: the engine only ran on ign.1 and ign.2 did NOT function anymore! Enough to go absolutely insane.... To be continued! Bart Verstuurd vanaf mijn iPad Op 19 jul. 2015 om 15:42 heeft Richard Girard < aslsa.rng@gmail.com> het volgende geschreven: Bart, Don't know if you've had any luck with this issue, but here are some more things to check. Wire/Coil and Wire/Boot connection. Trim a quarter inch or so (6mm) from the each end of the wire so that the screw inside the coil and boot can get a firm connection. While you have the boots off, check them for proper resistance, they should be 5 ohms. If they are too much more consider replacing them. You can get generics that are 1/10 the price Rotax charges. Test the spark plug leads, too. They're wire core and s/b zero ohms. Test your mag switches for intermittent failure. Just use an ohm meter and flip the switch a couple of dozen times and see if the switch has a failure. Rick Girard On Sun, Jul 12, 2015 at 2:19 PM, Guy Buchanan wrote: I'm going to say broken ignition (not plug) wire. See this on the 912 all the time. Use a continuity tester with needles to poke through the insulation. Work the wires to find the break. Guy B. Sent from my iPod > On Jul 12, 2015, at 11:45 AM, Bart Rond < bartrond@hotmail.com> wrote: > > > Hi fellow 2-stroke flyers, > > I am currently working on testruns and (hopefully) testflights with my restoration project Pulsar 1, equipped with Rotax 582 grey head. > A few testflights had to be cancelled, because one of the two ignitions failed in the run-up before take-off. So far, we could not find the cause of this failure. > It does not fail constantly, sometimes it works and sometimes it doesn't! > We suspect one of the ignition coils. Does anyone recognise this problem? > > Cheers, Bart > > Verstuurd vanaf mijn iPad > > > > =========== - xEngines-List" rel="noreferrer" target="_blank"> http://www.matronics.com/Navigator?RotaxEngines-List =========== FORUMS - eferrer" target="_blank"> http://forums.matronics.com =========== b Site - -Matt Dralle, List Admin. rel="noreferrer" target="_blank"> http://www.matronics.com/contribution =========== -- Believe those who are seeking the truth, doubt those who find it. -Andre Gide D============================================= Engines-List"">http://www.matronics.com/Navigator?RotaxEngines-List D============================================= //forums.matronics.com D============================================= ot;">http://www.matronics.com/contribution D============================================= ________________________________ Message 3 _____________________________________ Time: 07:54:21 PM PST US Subject: Re: RotaxEngines-List: 912 ULS Fuel Pressure From: Richard Girard When I was growing up vapor lock was not an uncommon in the autos of the 50's and 60's. Now it's virtually unheard of. Why? The engines of the time had block mounted fuel pumps. Fuel was pulled from the tank into a hot engine compartment. Sound familiar? Now the fuel pumps are in the tank and push fuel all the way to the injector rails. To keep the fuel, which is at 40+ psi, excess fuel is sent back to the tank to cool. Rotax has had the return line in its recommended fuel system but have the manufacturer's kept up with the rest of the system? A 912 ULS consumes 7 gallons an hour at full throttle. That's 1617 cu. in. of gas (air) that has to be let in to the tank to replace the 1617 cu. in. of gas that's been pumped out. Do the simple things first and start with the basics. Check all vents to make sure they are clear. Next, raise the tail of the aircraft to flight position, disconnect the fuel line at the mechanical pump and time the fuel flow for 6 minutes. Measure how much fuel ran out and multiply X 10. That's the maximum fuel flow potential you can get to the pump. Until you know that you're just casting about in the dark. Rick Girard do not archive On Wed, Jul 22, 2015 at 6:51 AM, david park wrote: > I have exactly the same experience, this was after fitting the new > mechanical pump which operates at a slightly higher pressure, it didn't > happen before the new pump was fitted.? > The drop in pressure does not effect the engine performance but am wary of > switching the electric pump back on if required. > Regards Dave Park G-LDVO > On 21 Jul 2015, at 22:29, Carl wrote: > > HI Stan > One year ago I had the same symptoms that you had. I believe this was > caused by the fact that the electric pump has a slightly higher pressure > than the engine pump and this causes the engine pump to stop pumping while > the electric pump is "on." This stagnation of fuel in the engine pump > during TO/Climb cause that fuel to vaporize and a momentary loss of > pressure when the electric pump is turned "OFF". > I've moved my gascolator, filter and boost pump to the rear compartment > and firesleeved all the lines. I also ran a return line to my right wing > tank. Seam to have helped some but I still see the pressure drop and the > occasional warning light when I turn the boost pump "OFF". Never affected > the engine but always ready to reselect to boost pump. > After shutdown on a hot day burning auto fuel, put an ear close to the > engine pump; bet you will hear the fuel boiling. > Carl > > > ----- Original Message ----- > *From:* Stan Tew > *To:* rotaxengines-list@matronics.com > *Sent:* Monday, July 13, 2015 6:47 PM > *Subject:* RotaxEngines-List: 912 ULS Fuel Pressure > > My 912 ULS mounted in my Rans S7-S has 438 hr. I replaced the old style > mechanical pump as recommended by Rotax. I have an electric fuel pump and > fuel pressure gauge. I usually take off with the electric pump running in > addition to the mechanical pump. When I level off to cruise I turn off the > electric pump. My pressure usually is about 4.5 psi. Last week I was flying > and noticed the EIS warning light and it identified my fuel pressure to be > about 0.9 psi. I quickly turned on the electric pump. The pressure went to > about 3.5 psi. I flew back and landed without incident. The engine never > faltered. > > Any suggestion on how to test the mechanical pump? Any suggestion on what > the problem might be? I have not had opportunity to remove the cowl to make > any visual checks. > > Stan Tew > N29TD > > * > > href="http://www.matronics.com/Navigator?RotaxEngines-List ">http://www.matronics.com/Navigator?RotaxEngines-List > href="http://forums.matronics.com ">http://forums.matronics.com > href="http://www.matronics.com/contribution ">http://www.matronics.com/c > * > > * > > href="http://www.matronics.com/Navigator?RotaxEngines-List ">http://www.matronics.com/Navigator?RotaxEngines-List > href="http://forums.matronics.com/ ">http://forums.matronics.com > href="http://www.matronics.com/contribution ">http://www.matronics.com/contribution > > * > > > * > > > * > > -- Believe those who are seeking the truth, doubt those who find it. -Andre Gide ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.