---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Thu 08/10/06: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:28 AM - 582 cold seizure (Dave G.) 2. 04:04 AM - fuel return system rotax 912s (fxcon) 3. 04:43 AM - Re: fuel return system rotax 912s (MR PAUL MITCHELL) 4. 11:33 AM - Re: fuel return system rotax 912s (Thilo Kind) ________________________________ Message 1 _____________________________________ Time: 03:28:00 AM PST US From: "Dave G." Subject: RotaxEngines-List: 582 cold seizure ----- Original Message ----- From: "Ray" Newsgroups: rec.aviation.ultralight Sent: Thursday, August 10, 2006 4:18 AM Subject: Rotax 582 cold seizure > maybe someone can help me out with this one a friend of mine was going > to a farm strip early ish one morning tempreture was cool about 8 deg c > he did a good warm up taxied out ,took of and promptly seized at the > top of the climb out no big problem at a 1000 ft above the airfield > ,anyway I stripped the top end of the motor and sure enough one piston > had seized giving the classic four corner marks of a cold seizure and > we put it down to not warming up enough, the engine had done just over > 200 hrs and was well maintained and the other piston was not marked at > all > So the motor was rebuilt with new parts I ground run it for approx 20 > mins at vairying loads but not full power and handed it over to my > friend who started the rotax run in procedure with the trike tied to > the hanger at 59 mins at the full power run it seized again, on > stripping it was exactly the same as before with the four corner marks > of a cold seizure ,he assures me he had the right fuel mix 50 to one > the jetting is correct piston bore clearances are correct and again the > other piston looks perfect > the engine is in an Airborne outback trike it is a blue head motor and > it has a new thermostat > he tells me all temps were correct > I know the rotax run in may be a bit aggressive maybe he should have > gone a little easyer > any help would be most appriciated > thanks > Ray > ________________________________ Message 2 _____________________________________ Time: 04:04:45 AM PST US From: "fxcon" Subject: RotaxEngines-List: fuel return system rotax 912s Some advice please re rotax fuel return system. Is this always necessary? Do some installations run succesfully without it,say, with adequate fuel line insulation & perhaps with dedicated air vent.to the fuel system What is its main purpose-to cool the fuel by recirculating warm fuel back into the tank,or perhaps to allow any fuel vapour to be purged from the system? All advice welcome. Frank Connell Australia. ----- Original Message ----- From: Dave G. To: rotaxengines-list@matronics.com Sent: Thursday, August 10, 2006 8:27 PM Subject: RotaxEngines-List: 582 cold seizure ----- Original Message ----- From: "Ray" Newsgroups: rec.aviation.ultralight Sent: Thursday, August 10, 2006 4:18 AM Subject: Rotax 582 cold seizure > maybe someone can help me out with this one a friend of mine was going > to a farm strip early ish one morning tempreture was cool about 8 deg c > he did a good warm up taxied out ,took of and promptly seized at the > top of the climb out no big problem at a 1000 ft above the airfield > ,anyway I stripped the top end of the motor and sure enough one piston > had seized giving the classic four corner marks of a cold seizure and > we put it down to not warming up enough, the engine had done just over > 200 hrs and was well maintained and the other piston was not marked at > all > So the motor was rebuilt with new parts I ground run it for approx 20 > mins at vairying loads but not full power and handed it over to my > friend who started the rotax run in procedure with the trike tied to > the hanger at 59 mins at the full power run it seized again, on > stripping it was exactly the same as before with the four corner marks > of a cold seizure ,he assures me he had the right fuel mix 50 to one > the jetting is correct piston bore clearances are correct and again the > other piston looks perfect > the engine is in an Airborne outback trike it is a blue head motor and > it has a new thermostat > he tells me all temps were correct > I know the rotax run in may be a bit aggressive maybe he should have > gone a little easyer > any help would be most appriciated > thanks > Ray > ________________________________ Message 3 _____________________________________ Time: 04:43:09 AM PST US From: "MR PAUL MITCHELL" Subject: Re: RotaxEngines-List: fuel return system rotax 912s Frank, I live in the Uk and we do have some warm days. I would say the return line is a must. It's purpose is to return any vapour lock or air bubbles back to the tank. I can see mine while I am flying and there are bubbles going back to the tank in a steady stream. Not a lot but they are there. Paul Mitchell ----- Original Message ----- From: fxcon To: rotaxengines-list@matronics.com Sent: Thursday, August 10, 2006 12:03 PM Subject: RotaxEngines-List: fuel return system rotax 912s Some advice please re rotax fuel return system. Is this always necessary? Do some installations run succesfully without it,say, with adequate fuel line insulation & perhaps with dedicated air vent.to the fuel system What is its main purpose-to cool the fuel by recirculating warm fuel back into the tank,or perhaps to allow any fuel vapour to be purged from the system? All advice welcome. Frank Connell Australia. ----- Original Message ----- From: Dave G. To: rotaxengines-list@matronics.com Sent: Thursday, August 10, 2006 8:27 PM Subject: RotaxEngines-List: 582 cold seizure ----- Original Message ----- From: "Ray" Newsgroups: rec.aviation.ultralight Sent: Thursday, August 10, 2006 4:18 AM Subject: Rotax 582 cold seizure > maybe someone can help me out with this one a friend of mine was going > to a farm strip early ish one morning tempreture was cool about 8 deg c > he did a good warm up taxied out ,took of and promptly seized at the > top of the climb out no big problem at a 1000 ft above the airfield > ,anyway I stripped the top end of the motor and sure enough one piston > had seized giving the classic four corner marks of a cold seizure and > we put it down to not warming up enough, the engine had done just over > 200 hrs and was well maintained and the other piston was not marked at > all > So the motor was rebuilt with new parts I ground run it for approx 20 > mins at vairying loads but not full power and handed it over to my > friend who started the rotax run in procedure with the trike tied to > the hanger at 59 mins at the full power run it seized again, on > stripping it was exactly the same as before with the four corner marks > of a cold seizure ,he assures me he had the right fuel mix 50 to one > the jetting is correct piston bore clearances are correct and again the > other piston looks perfect > the engine is in an Airborne outback trike it is a blue head motor and > it has a new thermostat > he tells me all temps were correct > I know the rotax run in may be a bit aggressive maybe he should have > gone a little easyer > any help would be most appriciated > thanks > Ray > ------------------------------------------------------------------------- ----- No virus found in this incoming message. 09-Aug-06 ________________________________ Message 4 _____________________________________ Time: 11:33:16 AM PST US From: "Thilo Kind" Subject: Re: RotaxEngines-List: fuel return system rotax 912s Hi Frank, most Rotax 912, that I know of, don't have the fuel return (including mine, a Zodiac CH 601 HDS). No problems with that set-up, except during re-starts on hot days. In such cases, the hot engine and the lack of air going through the cowling will create vapor lock, which will make it difficult to re-start. One way is to take the cowling off, so that the hot air can get out. Another way, we just learned from a Rotx shop is to switch on the electrical fuel pump, keep it running for 3 minutes, switch it off, push a throttle ever so slightly forward and start (without choke). Works well on the D40 in our flying club here. I haven't tried that yet on my Zodiac. Best regards Thilo Kind ----- Original Message ----- From: fxcon To: rotaxengines-list@matronics.com Sent: Thursday, August 10, 2006 1:03 PM Subject: RotaxEngines-List: fuel return system rotax 912s Some advice please re rotax fuel return system. Is this always necessary? Do some installations run succesfully without it,say, with adequate fuel line insulation & perhaps with dedicated air vent.to the fuel system What is its main purpose-to cool the fuel by recirculating warm fuel back into the tank,or perhaps to allow any fuel vapour to be purged from the system? All advice welcome. Frank Connell Australia. ----- Original Message ----- From: Dave G. To: rotaxengines-list@matronics.com Sent: Thursday, August 10, 2006 8:27 PM Subject: RotaxEngines-List: 582 cold seizure ----- Original Message ----- From: "Ray" Newsgroups: rec.aviation.ultralight Sent: Thursday, August 10, 2006 4:18 AM Subject: Rotax 582 cold seizure > maybe someone can help me out with this one a friend of mine was going > to a farm strip early ish one morning tempreture was cool about 8 deg c > he did a good warm up taxied out ,took of and promptly seized at the > top of the climb out no big problem at a 1000 ft above the airfield > ,anyway I stripped the top end of the motor and sure enough one piston > had seized giving the classic four corner marks of a cold seizure and > we put it down to not warming up enough, the engine had done just over > 200 hrs and was well maintained and the other piston was not marked at > all > So the motor was rebuilt with new parts I ground run it for approx 20 > mins at vairying loads but not full power and handed it over to my > friend who started the rotax run in procedure with the trike tied to > the hanger at 59 mins at the full power run it seized again, on > stripping it was exactly the same as before with the four corner marks > of a cold seizure ,he assures me he had the right fuel mix 50 to one > the jetting is correct piston bore clearances are correct and again the > other piston looks perfect > the engine is in an Airborne outback trike it is a blue head motor and > it has a new thermostat > he tells me all temps were correct > I know the rotax run in may be a bit aggressive maybe he should have > gone a little easyer > any help would be most appriciated > thanks > Ray >