---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Tue 09/12/06: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:02 PM - New 912 Engine Starting Problem (Hugh McKay III) 2. 02:05 PM - Re: Wandering RPM (Guy Buchanan) 3. 02:18 PM - Re: New 912 Engine Starting Problem (Thilo Kind) 4. 02:34 PM - Re: New 912 Engine Starting Problem (sonny) 5. 02:52 PM - Re: Wandering RPM (=?ISO-8859-1?Q?J=F3hann_Gestur?=) 6. 03:37 PM - Re: New 912 Engine Starting Problem (Jack Kuehn) 7. 08:09 PM - Re: Wandering RPM (Guy Buchanan) ________________________________ Message 1 _____________________________________ Time: 02:02:46 PM PST US From: "Hugh McKay III" Subject: RotaxEngines-List: New 912 Engine Starting Problem Gentlemen: After running my new Rotax 912UL in my Allegro 2000 for four successful trial runs, I decided to drain the main tank and refill it with new fuel. I drained the tank completely through the low point drain and refilled the tank about half full. When I tried to re-start the engine, it would not hit. It just turns over and over. Ignition is on, choke is on, and I am operating the electric fuel pump during the start sequence. I have tried three times to start the engine with the same result. I have done nothing different from the initial four runs other than draining the tank and refilling. Could I have a vapor lock or trapped air somewhere? I would think that the electric fuel pump would take care of air or a vapor lock in the lines between the pump and the carbs. Fuel bowls have stayed dry. Any suggestions how to find the problem, and correct it? Hugh McKay Allegro 2000 N661WW ________________________________ Message 2 _____________________________________ Time: 02:05:50 PM PST US From: Guy Buchanan Subject: Re: RotaxEngines-List: Wandering RPM At 04:09 PM 9/11/2006, you wrote: >REF: > >I've got a 582 that likes to wander +/- 100-200 RPM when cruising at 5800. >(Actually, pretty much anytime.) It appears to be more than just prop >loading, as I have to chase it with the throttle, and not just the >elevator. Any ideas? >---------------------------------------------- >Guy, > > How old are your crank seals? They'll do funny things when just > starting to leak. Email Green Sky or Lockwood and ask their advise. > >Frank Clyma >Jacksonville, FL > Yes. How about 14 years old? I guess it's time for a rebuild. (But Bob Robertson already told me that.) What else happens when they start leaking? Guy Buchanan K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar. Do not archive ________________________________ Message 3 _____________________________________ Time: 02:18:16 PM PST US From: "Thilo Kind" Subject: Re: RotaxEngines-List: New 912 Engine Starting Problem Hi Hugh, suggest to check the fuel lines to the carburetors with the electrical fuerl pumps running. Could be, that you are sucking fuel from the tanks to the electrical fuel pump. With the tank now half full (less pressure) you might create vapour lock in the suction line from tank to electrical pump. Good luck Thilo ----- Original Message ----- From: Hugh McKay III To: rotaxengines-list@matronics.com Sent: Tuesday, September 12, 2006 11:00 PM Subject: RotaxEngines-List: New 912 Engine Starting Problem Gentlemen: After running my new Rotax 912UL in my Allegro 2000 for four successful trial runs, I decided to drain the main tank and refill it with new fuel. I drained the tank completely through the low point drain and refilled the tank about half full. When I tried to re-start the engine, it would not hit. It just turns over and over. Ignition is on, choke is on, and I am operating the electric fuel pump during the start sequence. I have tried three times to start the engine with the same result. I have done nothing different from the initial four runs other than draining the tank and refilling. Could I have a vapor lock or trapped air somewhere? I would think that the electric fuel pump would take care of air or a vapor lock in the lines between the pump and the carbs. Fuel bowls have stayed dry. Any suggestions how to find the problem, and correct it? Hugh McKay Allegro 2000 N661WW ________________________________ Message 4 _____________________________________ Time: 02:34:54 PM PST US From: sonny Subject: Re: RotaxEngines-List: New 912 Engine Starting Problem Hi Hugh, I typically run my electric fuel pump until my 2 psi fuel pressure light goes out plus about 5 seconds. This puts fuel in the float bowls and pressurizes the fuel lines. I've never had a starting problem. My guess is that you not only drained fuel from the tanks, but the lines as well (gravity fed back to the tanks). Regards, Sonny W. ----- Original Message ---- From: Hugh McKay III Sent: Tuesday, September 12, 2006 3:00:50 PM Subject: RotaxEngines-List: New 912 Engine Starting Problem Gentlemen: After running my new Rotax 912UL in my Allegro 2000 for four successful trial runs, I decided to drain the main tank and refill it with new fuel. I drained the tank completely through the low point drain and refilled the tank about half full. When I tried to re-start the engine, it would not hit. It just turns over and over. Ignition is on, choke is on, and I am operating the electric fuel pump during the start sequence. I have tried three times to start the engine with the same result. I have done nothing different from the initial four runs other than draining the tank and refilling. Could I have a vapor lock or trapped air somewhere? I would think that the electric fuel pump would take care of air or a vapor lock in the lines between the pump and the carbs. Fuel bowls have stayed dry. Any suggestions how to find the problem, and correct it? Hugh McKay Allegro 2000 N661WW ________________________________ Message 5 _____________________________________ Time: 02:52:55 PM PST US From: =?ISO-8859-1?Q?J=F3hann_Gestur?= Subject: Re: RotaxEngines-List: Wandering RPM --> RotaxEngines-List message posted by: =?ISO-8859-1?Q?J=F3hann_Gestur?= Hello Guy. When there is excessive air entering the engine via leaky seals, your fuel mixture gets lean and the EGT will rise, which could cause seizure. Your problem is most likely air leak if the rpm is wandering. Good luck with the overhaul. Regards, Johann G. Iceland. Guy Buchanan wrote: > At 04:09 PM 9/11/2006, you wrote: > >> REF: >> >> I've got a 582 that likes to wander +/- 100-200 RPM when cruising at >> 5800. >> (Actually, pretty much anytime.) It appears to be more than just prop >> loading, as I have to chase it with the throttle, and not just the >> elevator. Any ideas? >> ---------------------------------------------- >> Guy, >> >> How old are your crank seals? They'll do funny things when just >> starting to leak. Email Green Sky or Lockwood and ask their advise. >> >> Frank Clyma >> Jacksonville, FL >> > > > Yes. How about 14 years old? I guess it's time for a rebuild. (But Bob > Robertson already told me that.) What else happens when they start > leaking? > > Guy Buchanan > K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar. > > Do not archive > >* > > >* > ________________________________ Message 6 _____________________________________ Time: 03:37:37 PM PST US From: Jack Kuehn Subject: Re: RotaxEngines-List: New 912 Engine Starting Problem --> RotaxEngines-List message posted by: Jack Kuehn Try disconnecting the fuel lines at the carburetors, one at a time, and turning on the electric pump briefly to clear the line. Make sure fuel is flowing. I have had slow starting after draining things out, and I do not think you have a real problem here, just no fuel getting to the engine. Jack Hugh McKay III wrote: > Gentlemen: > > > > After running my new Rotax 912UL in my Allegro 2000 for four > successful trial runs, I decided to drain the main tank and refill it > with new fuel. I drained the tank completely through the low point > drain and refilled the tank about half full. When I tried to re-start > the engine, it would not hit. It just turns over and over. Ignition is > on, choke is on, and I am operating the electric fuel pump during the > start sequence. I have tried three times to start the engine with the > same result. I have done nothing different from the initial four runs > other than draining the tank and refilling. Could I have a vapor lock > or trapped air somewhere? I would think that the electric fuel pump > would take care of air or a vapor lock in the lines between the pump > and the carbs. Fuel bowls have stayed dry. Any suggestions how to find > the problem, and correct it? > > > > Hugh McKay > > Allegro 2000 > > N661WW > >* > > >* > ________________________________ Message 7 _____________________________________ Time: 08:09:34 PM PST US From: Guy Buchanan Subject: Re: RotaxEngines-List: Wandering RPM --> RotaxEngines-List message posted by: Guy Buchanan At 02:53 PM 9/12/2006, you wrote: >When there is excessive air entering the engine via leaky seals, your >fuel mixture gets lean and the EGT will rise, which could cause seizure. >Your problem is most likely air leak if the rpm is wandering. How much do you think the EGT will vary? Guy Buchanan K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar. Do not archive