Original Posted By: "DJ Vegh"
Hey Gang,I need to call upon your expertise regarding a carburetor that is not justleaking gas, but pouring out. The carburetor is on an Cont. A-80 engine attached to a GN-1. Here is the rest of the story. The plane was last flown two years ago andhas been sitting idle in a hanger. (don=92t ask why it has not been flown=85..=85=85that is another story) It had a =BC tank of auto gas and the gas tankswitched to the on-position. (another story)Last weekend, the mechanic came out to do an annual. The compressionon all four cylinders was between 73-78 over 80. He then tried to start it.After ten tries, the engine fired up and then died. The fuel switch was intheOff position. He tried to start it again but it would not. He then drainedallof the old gas and put in $10.00 of Avgas. Again he tried and tried tostartit but could not. He pushed it back into the hanger and came out againthe next morning. He found the carburetor leaked most of the gas but therewas enough to try to start it again. After a few turns of the prop, gasjustpoured out of the carburetor. He feels the carburetor should be overhauledand bench tested.I went through my paperwork and found the original receipt of the carburetorand saw where the plane builder bought an overhauled and bench checkedStromberg carburetor in 1983 from El Reno Aviation of Oklahoma for $259.00(includes postage and insurance)I called them this morning and found out they no longer do that kind of workand recommended nearby Martin Inductions Systems. I talked to a GeneMartin who said the car gas probably gummed up the inside works.He said an overhaul would run $350.00. A needle and seat another$200 and a float could run the bill up to $650.00. It would take about aweek to ten days for turnaround.I called the previous owner of the plane and he said that being anExperimental, I could carefully take the carburetor apart and cleanit. He felt 95% sure it was just gummed up from the car gas and prolongedinactivity. He said carburetor cleaner, Q-tips and a clean cloth should clean it up to working condition.I feel his advice is worth taking however, I do not have a manual for thecarburetor as how to do the overhaul. Does anybody in this group have amanual or can scan the procedure to me? Or do you know of a place onlinewhere I could go and get this information?Here are the particulars: Stromberg NAS3A1 A18033B-4I do not know if it has the Neoprene tip, steel or Delrin needle.If I have to fix or replace the carburetor, where is the best place to sendit tofor repair or to shop for a replacement carburetor.I live in Dallas but will drive anywhere within reason to get thiscarburetor fixed.Thanks guys for any insight or help you can provide.Mike KingGN-1Dallas________________________________________________________________________________
Pietenpol-List: Stromberg Carburetor
Re: Pietenpol-List: Stromberg Carburetor
Original Posted By: Mike King
Mogas is the worst thing you can put through a Stromberg. If you don't have thestainless needle you'll most certainly have problems with Mogas. I have an NAS-3A1 on my Corvair/GN-1. I plan to only use 100LL.Also remember that the NAS-3A1 does not have mixture cut-off and the needles arenotorius for not sealing completely which will cause you to drain your entirefuel tank unless you shut the fuel off before it gets to the carb.I think the place that overhauls Strombergs is called Precision Aero or somethinglike that. Expect to pay big time though. You'd be better off buying themanual from AS&S and doing the work yourself. DJ----- Original Message -----
Mogas is the worst thing you can put through a Stromberg. If you don't have thestainless needle you'll most certainly have problems with Mogas. I have an NAS-3A1 on my Corvair/GN-1. I plan to only use 100LL.Also remember that the NAS-3A1 does not have mixture cut-off and the needles arenotorius for not sealing completely which will cause you to drain your entirefuel tank unless you shut the fuel off before it gets to the carb.I think the place that overhauls Strombergs is called Precision Aero or somethinglike that. Expect to pay big time though. You'd be better off buying themanual from AS&S and doing the work yourself. DJ----- Original Message -----
RE: Pietenpol-List: Stromberg Carburetor
Original Posted By: owner-pietenpol-list-server(at)matronics.com
DJ,I appreciate the comments. Yes, I took some advice from someone about fuelfor a 1940 aviation engine. Anyway,I tried Precision Aero and found it to be an R/C web site. Could theStromberg overhaul shop be under a different name?Thanks again.Mike-----Original Message-----
DJ,I appreciate the comments. Yes, I took some advice from someone about fuelfor a 1940 aviation engine. Anyway,I tried Precision Aero and found it to be an R/C web site. Could theStromberg overhaul shop be under a different name?Thanks again.Mike-----Original Message-----
Re: Pietenpol-List: Stromberg Carburetor
Original Posted By: Mike King
Mike,What DJ said about auto gas is on the money. After a few monthes my gascolatorgasket AND the gasket on the fuel cap, both started to distort. So I suspectyou have the neoprene needle in your carb like I did/do. Get the parts and do it yourself. Only critical points are to document how farany needles are in(count in half turns to fully closed) And you have to shimthe float needle seat to get a certain height of fuel in the bowl with a measuredcolumn of fuel on the intake. Not hard to do,,,just fasten a piece of cleartubibg to the wall and measure the height of gas in the bowl. If it's toolow/high dump it all out, reshim, and try again. Reassemble, replace the zillionsafety wires, and you're good to go.If you're not comfortable with it, get the parts and the manual and get a friendwhose mechanically inclined. The manual is literally step by step.I did my own and nothing flew off yet :)My biggest headache with the carb was to set the idle mixture screw. Once on anapproach, went to give it fuel from idle, and it coughed, sputtered, and startedpuking black smoke. Finally got it right. So check what the screw is before taking it apartwalt evansNX140DL ----- Original Message -----
Mike,What DJ said about auto gas is on the money. After a few monthes my gascolatorgasket AND the gasket on the fuel cap, both started to distort. So I suspectyou have the neoprene needle in your carb like I did/do. Get the parts and do it yourself. Only critical points are to document how farany needles are in(count in half turns to fully closed) And you have to shimthe float needle seat to get a certain height of fuel in the bowl with a measuredcolumn of fuel on the intake. Not hard to do,,,just fasten a piece of cleartubibg to the wall and measure the height of gas in the bowl. If it's toolow/high dump it all out, reshim, and try again. Reassemble, replace the zillionsafety wires, and you're good to go.If you're not comfortable with it, get the parts and the manual and get a friendwhose mechanically inclined. The manual is literally step by step.I did my own and nothing flew off yet :)My biggest headache with the carb was to set the idle mixture screw. Once on anapproach, went to give it fuel from idle, and it coughed, sputtered, and startedpuking black smoke. Finally got it right. So check what the screw is before taking it apartwalt evansNX140DL ----- Original Message -----
RE: Pietenpol-List: Stromberg Carburetor
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Walt,Great information. I really appreciate everyone=92s input. I will not again put auto gas in my engine. Now that my health is better,I will be flying my plane more often and will not go through this experienceagain.I do have a friend who is mechanically inclined. Now I need to get a manualandget started. I tried to find one online but will probably have to order onefrom asupply shop.Thanks again for all the useful information.Mike-----Original Message-----
Walt,Great information. I really appreciate everyone=92s input. I will not again put auto gas in my engine. Now that my health is better,I will be flying my plane more often and will not go through this experienceagain.I do have a friend who is mechanically inclined. Now I need to get a manualandget started. I tried to find one online but will probably have to order onefrom asupply shop.Thanks again for all the useful information.Mike-----Original Message-----
Pietenpol-List: Stromberg Carburetor
Original Posted By: BARNSTMR(at)aol.com
Re: Pietenpol-List: Stromberg Carburetor
Original Posted By: Mike King
Mike,Just keep one great tool in mind. The digital camera. Even the pictures are free,no film to buy. Just take a pic before every piece it taken off , if youwant to. You can't go wrong. It all looks easy when it's all together, but lookat a basket of parts, and it's a different ballgame!walt evansNX140DL ----- Original Message -----
Mike,Just keep one great tool in mind. The digital camera. Even the pictures are free,no film to buy. Just take a pic before every piece it taken off , if youwant to. You can't go wrong. It all looks easy when it's all together, but lookat a basket of parts, and it's a different ballgame!walt evansNX140DL ----- Original Message -----
Re: Re: Pietenpol-List: Stromberg Carburetor
Original Posted By:> "walt evans"
Hi Mike,One other tip, when you are overhauling your carburetor.I bought the Stromberg overhaul kit from Fresno Airparts (inside front cover ofTrade-a-Plane) with the stainless steel needle valve. I assembled the carb andthen tested it and found that it leaked around the needle valve slightly (notas bad as my J-3 Cub did years ago when I ran car gas in it). In order tostop the leak, the needle valve and seat need to be "lapped" to get a good seal.I found the easiest way to do this was to chuck the needle in my drill presswith it set to its slowest speed and then I applied regular Crest toothpasteto the valve seat and pressed it up against the spinning needle. Crest toothpasteis a very mild abrasive and makes a decent lapping compound. Once I didthis and reassembled the carb (after cleaning everything thoroughly, it wastotally leak free and worked like a champ. Mind you, I have not yet flown thisengine, so there might be other unforeseen problems.Jack PhillipsRaleigh, NCSpraying color coats now on NX899JP
Hi Mike,One other tip, when you are overhauling your carburetor.I bought the Stromberg overhaul kit from Fresno Airparts (inside front cover ofTrade-a-Plane) with the stainless steel needle valve. I assembled the carb andthen tested it and found that it leaked around the needle valve slightly (notas bad as my J-3 Cub did years ago when I ran car gas in it). In order tostop the leak, the needle valve and seat need to be "lapped" to get a good seal.I found the easiest way to do this was to chuck the needle in my drill presswith it set to its slowest speed and then I applied regular Crest toothpasteto the valve seat and pressed it up against the spinning needle. Crest toothpasteis a very mild abrasive and makes a decent lapping compound. Once I didthis and reassembled the carb (after cleaning everything thoroughly, it wastotally leak free and worked like a champ. Mind you, I have not yet flown thisengine, so there might be other unforeseen problems.Jack PhillipsRaleigh, NCSpraying color coats now on NX899JP
RE: Pietenpol-List: Stromberg Carburetor
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Hey Guys,Just want to let you know your input and advice were greatlyappreciated in resolving my malfunctioning Stromberg carburetor.A special thanks to Alex Sloan, Delton Perry, Oscar Zuniga, JackPhillips, Walt Evans and other knowledgeable Piet and GN-1enthusiasts for your insight.I just ordered a Stromberg carburetor overhaul kit from FresnoAirparts along with a manual to keep me honest and out oftrouble.The old girl should be back in the air in just a fewdays=85..thanks again to many of you.Have a good day.Mike KingGN-177MKDallasP.S. My 1940 Continental A-80 engine will not see auto gasagain.-----Original Message-----
Hey Guys,Just want to let you know your input and advice were greatlyappreciated in resolving my malfunctioning Stromberg carburetor.A special thanks to Alex Sloan, Delton Perry, Oscar Zuniga, JackPhillips, Walt Evans and other knowledgeable Piet and GN-1enthusiasts for your insight.I just ordered a Stromberg carburetor overhaul kit from FresnoAirparts along with a manual to keep me honest and out oftrouble.The old girl should be back in the air in just a fewdays=85..thanks again to many of you.Have a good day.Mike KingGN-177MKDallasP.S. My 1940 Continental A-80 engine will not see auto gasagain.-----Original Message-----
Re: Pietenpol-List: Stromberg Carburetor
Original Posted By: Mike King
Mike,Many carburetor leak becuase a particular service bulletin has not been compliedwith, causing the fuel to siphon out of the bowl through one of the jets. Youmay want to look this one up with precision airmotive as I don't have it offhand.Chris ----- Original Message -----
Mike,Many carburetor leak becuase a particular service bulletin has not been compliedwith, causing the fuel to siphon out of the bowl through one of the jets. Youmay want to look this one up with precision airmotive as I don't have it offhand.Chris ----- Original Message -----
Re: Pietenpol-List: Cont. 85 hp low oil pressure question
Original Posted By: "Bert Conoly"
Mike,The scenario you describe doesn't sound good. The fact that the oil pressuredrops significantly when the engine has warmed up indicates excessiveclearances within the engine causing an "internal hemorrhage" when the oilviscosity is reduced by high temperatures. And an elevated oil temperatureis a bad sign, as well.Chris Bobka probably has the correct diagnosis of the problem, and it seemsan engine overhaul is in the cards. However there is a possibility that theoil pump is badly worn and it is relatively easy to check it out first. But,unless their luck is a lot better than mine, the oil pump may be only partof the problem with excessive clearances existing throughout the engine. Ifthis is the case, it is best to dismantle the engine and overhaul it NOW!Shimming the oil pressure relief valve spring is NOT a cure because, asChris observed, it involves treating the symptom rather than the cause.Ideally, when all internal clearances are within the manufacturer'sspecified limits, the oil pressure should hold a fairly steady value, hotengine or cold engine.Sometimes the oil pressure relief valve seating is poor, and this can causelow oil pressure. But it is unlikely the cause of the problem you describe.Typically, the minimum hot idle oil pressure for the small Continentals is10 psi (stated in their overhaul manuals). Really, this seems to be awfullylow because in my experience it indicates a well-worn engine. I taught ahigh school aircraft maintenance course for 17 years and we used fivevenerable (and very tired) Continental A65 "practice" engines. They all hadlarge clearances and displayed the same oil pressure problem you describe.But, amazingly, they did run pretty well thus demonstrating what toughlittle engines they are.We didn't run them too much, or too hard, and theycertainly were not fit to fly!Increasing oil temperature accompanied by decreasing oil pressure are clearsigns of impending doom! In my opinion, the C85 you are describing is likelydue for a complete overhaul.Cheers,Graham Hansen (Pietenpol CF-AUN)________________________________________________________________________________
Mike,The scenario you describe doesn't sound good. The fact that the oil pressuredrops significantly when the engine has warmed up indicates excessiveclearances within the engine causing an "internal hemorrhage" when the oilviscosity is reduced by high temperatures. And an elevated oil temperatureis a bad sign, as well.Chris Bobka probably has the correct diagnosis of the problem, and it seemsan engine overhaul is in the cards. However there is a possibility that theoil pump is badly worn and it is relatively easy to check it out first. But,unless their luck is a lot better than mine, the oil pump may be only partof the problem with excessive clearances existing throughout the engine. Ifthis is the case, it is best to dismantle the engine and overhaul it NOW!Shimming the oil pressure relief valve spring is NOT a cure because, asChris observed, it involves treating the symptom rather than the cause.Ideally, when all internal clearances are within the manufacturer'sspecified limits, the oil pressure should hold a fairly steady value, hotengine or cold engine.Sometimes the oil pressure relief valve seating is poor, and this can causelow oil pressure. But it is unlikely the cause of the problem you describe.Typically, the minimum hot idle oil pressure for the small Continentals is10 psi (stated in their overhaul manuals). Really, this seems to be awfullylow because in my experience it indicates a well-worn engine. I taught ahigh school aircraft maintenance course for 17 years and we used fivevenerable (and very tired) Continental A65 "practice" engines. They all hadlarge clearances and displayed the same oil pressure problem you describe.But, amazingly, they did run pretty well thus demonstrating what toughlittle engines they are.We didn't run them too much, or too hard, and theycertainly were not fit to fly!Increasing oil temperature accompanied by decreasing oil pressure are clearsigns of impending doom! In my opinion, the C85 you are describing is likelydue for a complete overhaul.Cheers,Graham Hansen (Pietenpol CF-AUN)________________________________________________________________________________
> Re: Pietenpol-List: Stromberg Carburetor
Original Posted By:> Mike King
> To: > Subject: Re: Pietenpol-List: Stromberg Carburetor> > Mike,> What DJ said about auto gas is on the money. After a few monthes my gascolatorgasket AND the gasket on the fuel cap, both started to distort. So I suspectyou have the neoprene needle in your carb like I did/do. > Get the parts and do it yourself. Only critical points are to document how farany needles are in(count in half turns to fully closed) And you have to shimthe float needle seat to get a certain height of fuel in the bowl with a measuredcolumn of fuel on the intake. Not hard to do,,,just fasten a piece of cleartubibg to the wall and measure the height of gas in the bowl. If it's toolow/high dump it all out, reshim, and try again. Reassemble, replace the zillionsafety wires, and you're good to go.> If you're not comfortable with it, get the parts and the manual and get a friendwhose mechanically inclined. The manual is literally step by step.> I did my own and nothing flew off yet
> My biggest headache with the carb was to set the idle mixture screw. Once onan approach, went to give it fuel from idle, and it coughed, sputtered, and startedpuking black smoke. Finally got it right.> So check what the screw is before taking it apart> walt evans> NX140DL> ----- Original Message -----
> To: > Subject: Re: Pietenpol-List: Stromberg Carburetor> > Mike,> What DJ said about auto gas is on the money. After a few monthes my gascolatorgasket AND the gasket on the fuel cap, both started to distort. So I suspectyou have the neoprene needle in your carb like I did/do. > Get the parts and do it yourself. Only critical points are to document how farany needles are in(count in half turns to fully closed) And you have to shimthe float needle seat to get a certain height of fuel in the bowl with a measuredcolumn of fuel on the intake. Not hard to do,,,just fasten a piece of cleartubibg to the wall and measure the height of gas in the bowl. If it's toolow/high dump it all out, reshim, and try again. Reassemble, replace the zillionsafety wires, and you're good to go.> If you're not comfortable with it, get the parts and the manual and get a friendwhose mechanically inclined. The manual is literally step by step.> I did my own and nothing flew off yet
> My biggest headache with the carb was to set the idle mixture screw. Once onan approach, went to give it fuel from idle, and it coughed, sputtered, and startedpuking black smoke. Finally got it right.> So check what the screw is before taking it apart> walt evans> NX140DL> ----- Original Message -----