----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
Larry, You have the explanation right. Sealing the vents should be a no no. Bob Parker Mena, AR. ----- Original Message ----- From: "Larry Wilkins" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Cc: "'Bob Saville '" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[email protected]>; <[EMAIL PROTECTED]> Sent: Monday, April 22, 2002 9:21 AM Subject: Re: [COUPERS-TECH] [COUPERS] 87 Octane Gas > ----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- > > On 93405, I found that my caps would leak only on two occasions. First, in > flight if I didn't have the wing caps on perfectly parallel with the > centerline of the airplane, they would leak. Seems that the air would cause > a vacuum while going along the side of the cap if the cap wasn't straight. > Reach out and straighten the cap, and the leaking stopped. Second, almost > anytime I was on the ground, or on final approach, with low throttle > settings, she would leak out of the header tank. At low power settings, she > would pump more fuel than the return line could handle. In flight, I never > had that problem. On the ground I would just turn off the fuel line from > the wing tanks. Once in the air, I'd turn them back on. If I forgot to > do it, I'd soon be reminded as the fuel indicator would remind me in short > order. I suspect the return line was somewhat obstructed or the header tank > wouldn't have leaked at all. I can't imagine it would do any good to have > any of the vents sealed off. If the cap seals were good enough, the > resulting vacuum would have stopped the flow of fuel. The wing tanks could > (theoretically) have enough vacuum to actually collapse inward if they > didn't leak a little air. The header tank, with the absence of a vacuum > causing pump, would simply stop flowing fuel. In all cases, I can't see the > system functioning correctly without vents. > > Larry > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Cc: "'Bob Saville '" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; > <[email protected]>; <[EMAIL PROTECTED]> > Sent: Monday, April 22, 2002 12:26 AM > Subject: Re: [COUPERS-TECH] [COUPERS] 87 Octane Gas > > > > ----[Please read http://ercoupers.com/disclaimer.htm before following any > advice in this forum.]---- > > > > Pete. > > > > "to close off the main tank cap vents." > > > > What do you mean - closing the vent hole?? Please do not do that. > > I too have all three tanks vented and even though my system has been > converted to a later one (none > > vented wing tanks) ,mysteriously it works only with vented caps. > > Leave your system as it is! > > Or am I getting something wrong here??? > > > > Hartmut > > > > Pete Thomson wrote: > > > > > ----[Please read http://ercoupers.com/disclaimer.htm before following > any advice in this forum.]---- > > > > > > Good evening evryone. I have read with some interest the comments on > vapor > > > lock. I have vented gas caps on all 3 tanks and have been advised by the > > > service memorandums, which I am slowly going through during my annual > from > > > hell,to close off the main tank cap vents. I would sure appreciate some > > > feedback from all of you, do you have vented or unvented caps on wing > tanks > > > and or the nose tank? If you have closed the vents on the wing tanks, > where > > > does the air come from to take the place of the fuel? Thanks Alaska Pete > > > > > > -----Original Message----- > > > From: Bob Saville > > > To: [EMAIL PROTECTED] > > > Cc: [email protected]; [EMAIL PROTECTED] > > > Sent: 4/20/02 7:09 PM > > > Subject: RE: [COUPERS-TECH] [COUPERS] 87 Octane Gas > > > > > > ----[Please read http://ercoupers.com/disclaimer.htm before following > > > any advice in this forum.]---- > > > > > > Hi Ken, > > > Just a guess, but I'd say that the grounding wire going from your > > > mag switch to the mags is probably > > > grounding out at the back of ths switch. Since it effects both mags in > > > order to kill the engine > > > completely I'd say either the swithch itself or right at the top end of > > > the wires where they connect. > > > Could be that the wire has a little slack there and by raising the nose > > > it makes a bare wire(s) touch > > > some metal and thereby grounds out the mags as if the switch had been > > > turned off. > > > Like I said, just a guess, but one more thing to check before you > > > fly it again. It surely wouldn't > > > hurt to check both wires all the way to their respective mags to look > > > for a bad spot in the insulation. > > > Especially where it goes through a clamp or the firewall. Or if it is > > > 'rubbing' against any metal such > > > as the engine mount for example. > > > > > > Bob Saville > > > > > > [EMAIL PROTECTED] wrote: > > > > > > > ----[Please read http://ercoupers.com/disclaimer.htm before following > > > any advice in this forum.]---- > > > > > > > > I'll add my experience(s) to the list on the subject of engine > > > stoppage. > > > > > > > > I have an Alon. I've put about 350-400 hours on it without similar > > > engine > > > > incident. I did replace two pistons about 6 months ago. (I had real > > > low > > > > compression on one cylinder and low on the other one.) It already has > > > new > > > > slick mags (2 years ago). I only use 100LL. > > > > > > > > Last Nov my engine quit at about 300 feet. Fortunately there was a > > > nice > > > > field ahead of me so I landed uneventfully. It was a perfect carb ice > > > day > > > > and I still suspect that was the problem. I flew the plane out of the > > > field > > > > later in the day. > > > > > > > > I flew the plane several times after that without incident. But a > > > month > > > > ago, after flying around for about an hour I stopped at a local > > > airport for > > > > fuel and breakfast. As I rotated on take-off the engine quit. I set > > > the > > > > nose back down and the engine ran fine. I taxied back and it happened > > > > again. I did this three times with the same results. The engine > > > didn't > > > > sputter, it just quit--like the key had been turned off. The run ups > > > and > > > > static run-ups checked ok and taking off with carb heat on didn't > > > help. I > > > > should have tried lowering the tail while tied down and running but I > > > > didn't--too frustrated at the time. > > > > > > > > My Mechanic and I discussed all the possible problems and talked to > > > several > > > > other people, including other Alon and Ercoupe owners. The comments > > > were > > > > usually: (a) Alons just do that, keep current on emergency landings > > > (b) > > > > Alons do that because the gasolator sits too low on the firewall; > > > (c)the > > > > fuel line must have a hump in it causing a vapor lock; (d)the carb is > > > > contaminated; (e)it has nothing to do with the fuel, fuel line, carb > > > or > > > > vapor locks--something is shorting-out both magnetos---maybe a bad > > > ignition > > > > switch. > > > > > > > > So we checked the carb and it was clean and looked good. > > > > > > > > I re-routed the fuel line because there was just a slight hump in it. > > > The > > > > fuel line had been replaced about 2 years ago just because the old one > > > was > > > > ratty on one end. The slight hump had been there for the past 100 > > > hours + > > > > of flying. > > > > > > > > I checked the vent hole in the fuel line caps--all ok. > > > > > > > > I replaced the ignition switch although I can't imagine how the switch > > > would > > > > go bad such that raising the nose would cause it to short out. > > > > > > > > But I didn't find anything else unusual and there was no definitive > > > cause > > > > found for the engine quitting. After all of this, the plane flew just > > > fine. > > > > I flew it above the airport for a while before heading home. That was > > > last > > > > week and the weather has been bad ever since so I haven't gotten to do > > > > enough test flights to know if the problem is solved. > > > > > > > > I don't think my experiences really add anything accept more > > > confusion. > > > > Most probably our experiences are not caused by the same thing. > > > > > > > > Ken Doyle > > > > Alon N5477E > > > > Springfield, Mo > > > > > > > > > > > > > > > > > ==^================================================================ This email was sent to: [EMAIL PROTECTED] EASY UNSUBSCRIBE click here: http://topica.com/u/?aVxiLm.aVzvvT Or send an email to: [EMAIL PROTECTED] T O P I C A -- Register now to manage your mail! http://www.topica.com/partner/tag02/register ==^================================================================
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