Carburetor recommendations
-
PB Schafer
- Posts: 36
- Joined: Tue Apr 13, 2010 23:46
- Contact:
Carburetor recommendations
As a newcomer to the Aeronca community, I have received lots of advice and comments on the rebuild of a 7AC. I am now seeking input on the best (and naturally the least inexpensive) path to solving the carburetor issue. I have an A-65 with a Stromberg. I have been told it is not the best, and it is slowing becoming harder to repair and rebuild. I would like to upgrade to a Marvel/Tempest, but have no core, and a fixed income. I want a reliable system (having survived 1 off-airport already) and something to help prolong the life of the engine. Thanks for your support.
PB Schafer
" Those who say it cannot be done, should not bother the one doing it "
" Those who say it cannot be done, should not bother the one doing it "
-
David Johnson
- Posts: 584
- Joined: Sat Nov 20, 2004 08:28
- Location: Jasper, Georgia
- Contact:
Re: Carburetor recommendations
The Stromberg carb is perfect for the A-65. The only thing you will miss is no accelerator pump. Got to be careful of shoving the throttle in fast, especially when the engine is cold or has cooled a little. These carbs only have a few moving parts and run great. When set up correctly they seldom cause trouble. The Marvel carbs have lots more parts in them. I would not attempt to upgrade. Use the money somewhere else. As always, just my opinion. David J.
Re: Carburetor recommendations
I have to agree with David. These Stromberg NAS3-A1 carburetors are bullet-proof and have NO AD's is over 70 year of service. Not too many accessories can match that.
However....There are some "cautions" a pilot should know about them.
1. There is no accelerator pump on these small carbs so don't "firewall" the power on take-off or go-around. Just smoothly apply power to allow the venturi to pick up the fuel.
2. If you run car gas in your Champ.....you better have a stainless steel needle and SEAT. There have been crashes caused but the older neoprene tip needles that have swelled due to the ethenol in the fuel. If in doubt don't use car gas....
3. Have a good mechanic (or someone who knows about these carbs) to set up the float level correctly with adjusting the seat height. No diffiicult to do but it does take a little time. Many of these carbs are running (or dripping) due to an improperly set fuel bowl height.
4. Parts are in great supply since there is very little wear in operation. Basically gaskets are required in overhaul....maybe throttle shaft bushings.
These are great little carburetors for the Champ.
DC Krog
However....There are some "cautions" a pilot should know about them.
1. There is no accelerator pump on these small carbs so don't "firewall" the power on take-off or go-around. Just smoothly apply power to allow the venturi to pick up the fuel.
2. If you run car gas in your Champ.....you better have a stainless steel needle and SEAT. There have been crashes caused but the older neoprene tip needles that have swelled due to the ethenol in the fuel. If in doubt don't use car gas....
3. Have a good mechanic (or someone who knows about these carbs) to set up the float level correctly with adjusting the seat height. No diffiicult to do but it does take a little time. Many of these carbs are running (or dripping) due to an improperly set fuel bowl height.
4. Parts are in great supply since there is very little wear in operation. Basically gaskets are required in overhaul....maybe throttle shaft bushings.
These are great little carburetors for the Champ.
DC Krog
Re: Carburetor recommendations
I agree with both of the posters above. All three of the Champs on our field have Strombergs. They're a good carburetor for a simple engine like the A65's. Regarding the lack of an accelerator pump requires a bit more careful use of carb heat to prevent a lean out condition especially up here in the north country during the winter and as others have stated, don't bang the throttle in or it's: 'cough' - 'spit'-'Oh ####' 
. But then, I always felt the throttle should be brought in smoothly anyway.
MikeB
. But then, I always felt the throttle should be brought in smoothly anyway. MikeB
-
PB Schafer
- Posts: 36
- Joined: Tue Apr 13, 2010 23:46
- Contact:
Re: Carburetor recommendations
Hey, I really appreciate all the good info on the Stromberg. One other thing. I have a NAS3A1, but it does not have the mixture control installed. Would this be worthwhile to do, even though I understand it does not give you an idle cut-off?
PB Schafer
" Those who say it cannot be done, should not bother the one doing it "
" Those who say it cannot be done, should not bother the one doing it "
Re: Carburetor recommendations
PB,
Most of the mixtures are wired open anyway. Really can't see any advantage unless you're going to be going up to altitude. I've never used mine so I can't speak to that other than I've heard it's a sort of 'feast or famine' type mixture control. If the carburetor is working well, I'd leave it alone. My opinion-- others may have a different one.
MikeB
Most of the mixtures are wired open anyway. Really can't see any advantage unless you're going to be going up to altitude. I've never used mine so I can't speak to that other than I've heard it's a sort of 'feast or famine' type mixture control. If the carburetor is working well, I'd leave it alone. My opinion-- others may have a different one.
MikeB
Re: Carburetor recommendations
Depends a lot on where you live or are going to fly. Out here in the West we could not get along without a mixture control.
When I sold my Chief the new owner decided to disregard my recommendations and took off in July at 1 pm in the afternoon, heading direct home through the middle of New Mexico. It was about 107 degrees. He returned about 45 minutes later and almost ground-looped the airplane on landing, and catching the wingtip on the runway. He as well got a very graphic lesson on density altitude!
Called me once he was back in the chocks saying "something is wrong with the airplane" upon which I came out, looked at the plane and belly. Pulled the spark plugs, cleaned them and put them back in the engine then did a run-up. It ran fine now.
I then took him back along the belly and showed him the dark streaks where the rich fuel mixture had covered the plane. Turns out that he was a "lowlands pilot" and was told to never touch the mixture. Well that does not work here and he tried to take the plane up to 9500 without leaning and almost lost the plane as the engine was as he said "sputtering like all get out." All he needed to do was to lean the engine and it would have done fine. At takeoff his DA was around 4800 feet, so he really needed to lean for takeoff but was not interested in my advise.
He flew home on the airline the next morning and Tom Holmes came out a couple of weeks later to ferry the plane East. Funny thing is that he took the South route through El Paso that I tried to talk the new owner into and 2.5 days later the Chief was safe and sound, home in Alabama. Tom knows Aeronca's and as well knows very well how to lean the engine.
If you are flying over 3000 or so you could really use the mixture. Just depends on how and where you are flying.
When I sold my Chief the new owner decided to disregard my recommendations and took off in July at 1 pm in the afternoon, heading direct home through the middle of New Mexico. It was about 107 degrees. He returned about 45 minutes later and almost ground-looped the airplane on landing, and catching the wingtip on the runway. He as well got a very graphic lesson on density altitude!
Called me once he was back in the chocks saying "something is wrong with the airplane" upon which I came out, looked at the plane and belly. Pulled the spark plugs, cleaned them and put them back in the engine then did a run-up. It ran fine now.
I then took him back along the belly and showed him the dark streaks where the rich fuel mixture had covered the plane. Turns out that he was a "lowlands pilot" and was told to never touch the mixture. Well that does not work here and he tried to take the plane up to 9500 without leaning and almost lost the plane as the engine was as he said "sputtering like all get out." All he needed to do was to lean the engine and it would have done fine. At takeoff his DA was around 4800 feet, so he really needed to lean for takeoff but was not interested in my advise.
He flew home on the airline the next morning and Tom Holmes came out a couple of weeks later to ferry the plane East. Funny thing is that he took the South route through El Paso that I tried to talk the new owner into and 2.5 days later the Chief was safe and sound, home in Alabama. Tom knows Aeronca's and as well knows very well how to lean the engine.
If you are flying over 3000 or so you could really use the mixture. Just depends on how and where you are flying.
-
PB Schafer
- Posts: 36
- Joined: Tue Apr 13, 2010 23:46
- Contact:
Re: Carburetor recommendations
Well, I guess that any aircraft control item is no substitute for good judgement. (or poor)
Point well taken about the D/A. We fly out of a 500' elevation, and spend most of our time below 3000. In the summer sometimes we see 3K D/A at our field. Appreciate your input.
Point well taken about the D/A. We fly out of a 500' elevation, and spend most of our time below 3000. In the summer sometimes we see 3K D/A at our field. Appreciate your input.
PB Schafer
" Those who say it cannot be done, should not bother the one doing it "
" Those who say it cannot be done, should not bother the one doing it "
Re: Carburetor recommendations
Be careful if you have an A-65..........Per the TCDS for the engine, all models using Marvel-Schebler MA-3PA carburetor are limited to use of 80/87 octane fuel. When in doubt ask the guy putting his name in the logbook!
Re: Carburetor recommendations
JoeA's story remines me of the time I was flying a friend in his 182RG to Tucson. We were at altitude in the summer and was descending into Las Cruces, NM for fuel. I started moving the mixture to rich. At about 2 or 3000 ft above the ground, the engine started missing.....what the heck? Oh crap! Wait a minute, lets try to lean. Bingo, the engine started to run smooth again. Las Cruces is almost 4000 ft. msl.
So this flat lander learned by experience.....which is a good teacher, if you survive.
Dennis
So this flat lander learned by experience.....which is a good teacher, if you survive.
Dennis
-
Champ Dreamer
- Posts: 185
- Joined: Thu Mar 20, 2008 00:14
- Location: Colorado Springs
- Contact:
Re: Carburetor recommendations
Here at kfly (Colorado Springs) our field elevation is 6,840'. When the temp is in the high 80's, the DA is 10,000. Theoretically, a 65hp Champ won't fly?! However, I've seen it done (brave soul). Rate of climb was single digits 
Brian Walker
Hanging a C-85 on my Champ.
Brian Walker
Hanging a C-85 on my Champ.
-
james gevay
- Posts: 380
- Joined: Fri Mar 09, 2007 18:39
- Location: Anoka County MN
- Contact:
Re: Carburetor recommendations
There was an excellent article about Stromberg carbs in the August issue of Vintage Airplane, the Antique Classic division of the EAA. The issue is the one with the Champ on the cover and was written by Steve Krog.
In the article he talks about rebuilding the carbs and fuel leaks and setting the float height correctly. He speaks with Bob Kachergius at Uni-Tech Air management Systems Inc. who does all this work in these carbs.
The info I have from the magazine is,
13221 Windward Trail
Orland Park, Ill. 60462
708-267-7111
uni-tech@earthlink.net
In the article he talks about rebuilding the carbs and fuel leaks and setting the float height correctly. He speaks with Bob Kachergius at Uni-Tech Air management Systems Inc. who does all this work in these carbs.
The info I have from the magazine is,
13221 Windward Trail
Orland Park, Ill. 60462
708-267-7111
uni-tech@earthlink.net
Re: Carburetor recommendations
We've had our carburetors rebuilt by Bolduc at the Anoka County airport by the Twin Cites. Pricey but good. Always seems to work well and 'no leaks'.
Mike
Mike
Re: Carburetor recommendations
MikeB,
Don't understand your post. Using carb heat enrichens the mixture, it doesn't lean it??
Don't understand your post. Using carb heat enrichens the mixture, it doesn't lean it??
Gus Causbie
Ash Flat, AR
N83564, 7AC-2235, A65-8
Ash Flat, AR
N83564, 7AC-2235, A65-8
Re: Carburetor recommendations
Gus,
If we fly on skis during the winter and the temperature is 20 degrees or so the engine will 'lean out' due to the lack of a accelerator pump. Using carb heat does increase (and warm) the mixture somewhat which helps when advancing the throttle in cold weather. Especially true just after starting until the temperature comes up some. Also, on long approaches (for example) even with full carb heat you can't bang the throttle ahead or there will be a lot of coughing and spitting
from the cold engine.
MikeB
If we fly on skis during the winter and the temperature is 20 degrees or so the engine will 'lean out' due to the lack of a accelerator pump. Using carb heat does increase (and warm) the mixture somewhat which helps when advancing the throttle in cold weather. Especially true just after starting until the temperature comes up some. Also, on long approaches (for example) even with full carb heat you can't bang the throttle ahead or there will be a lot of coughing and spitting
from the cold engine. MikeB