Stromberg Overhaul

[smokiescfi]

Anyone know of any shops currently overhauling NA-S3A1's?

[DC Krog]

Hello Greg,

Before you send out your Carburetor I see that you are an A&P. Maybe you don't feel comfortable overhaul these simple carburetors but I have to tell you it is no big deal at all. There is a ton of information online regarding the set up and special tool you can make (again no big deal making the float guage and seat removal socket). The biggest question is what kind of fuel do you want to run (regarding the type of foat needle you prefer) and to make sure that all the parts inside are the CORRECT parts for your engine. You will need to download an overhaul manual from the internet and also google Stromberg NAS3-A1 float needle differences and a web page someone wrote about float settings will appear.

Overhaul kits are available from Fresno Airparts and I perfer to keep the Neoprene tip needle but that's your call and comfort level. As an A&P you can sign off the overhaul I/A/C with the latest overhaul manaul with I believe is 8/1/65.

What make the beauty of Champs/Cubs is the simplicity of the componets that drive them. The Stromberg NAS3-A1 is no exception. Just for your reference I looked into having my Carb overhauled by a "approved" shop and was quoted over $1000.00 and I said bull++it to that. I'm a A&P and with a bit of research and time making up some tools I overhaul my carburetor and my friends carburetor. Runs great and no DRIPS!!! If you have any questions drop me an e-mail I give you some tips.

Take Care,
DC Krog

P.S. Make sure you have the right Venturi #, Metering Jet#, Discharge Nozzle # for your Engine Model. It makes a big difference.

[MikeB]

I kind of agree with the above. The carbs are dirt simple. I think the carb on my H Farmall is about as complicated and I've overhauled Carter AFB carbs, Stanadyne diesel fuel injection pumps, etc. with good success. The bad news is I'm not a A & P and my IA doesn't like to mess with carbs (liability thing, I think) so we've been sending them to Bolduc at Blaine Country airport in the Twin Cites to the tune of about $600. On the other hand, if I had a A & P license I'd tackle the job.

MikeB

[smokiescfi]

Thanks guys. I am quite familiar with the carb, all of the components, tools, shop manual, etc. I have "overhauled" them in the past, and have a couple thousand hours flying A65 Stromberg equipped Champs. This carb was purchased off of Ebay with no paperwork, and I am in need of an 8130 Tag before installing the carb in a flight school rental airplane (high liability). The Fresno kits are great, but also come with no paperwork or traceability.

[MikeB]

Greg,
If it's a carb kit you need I'm pretty sure Bolduc will sell you one. I've bought lot of parts from them over the years. Usually a little high on the price but should come with the necessary 'paperwork' if you ask.
Darrell Bolduc is very easy to talk to and willing to answer any questions I've ever had. Everything we've sent up there has be A-OK when it comes back. I don't have his phone number but I'm sure you can 'goggle it' under Bolduc Aviation.
Hope this helps some!

Mike

[DC Krog]

Hello Greg,
I understand your "liability" question however don't get to wrapped up in the paperwork. You don't need a 8130 tag or a yellow tag. You (as an A&P and even better IA) determine the airworthiness of the componet. It doesn't matter if you bought the carb on E-Bay or found it in the trash bin your judgement and experience using current manuals and procedures under the Overhaul manual will return the componet to Airworthy Status with your signature and date signed. However it's your call and of course on your comfort level. The 8130/yellow tags apply to CRS which have are governed by their local PMI's which can be brutal with paper work and oversight. That's why the FAA is slowly killing avaition by useless oversight.

Any which way good luck with the Carb. And I agree with the poster above....My Farmall Cub carburetor is about the same complexity just smaller.

DC Krog

[smokiescfi]

In this day and age of lawsuits and strict regulations, don't feel I can not "get hung up in the paperwork". This is all I do, my certificates are my livelyhood, and at 45 years old, I'm not willing to risk my future to avoid paying a repair station to do the work and issue the paper. It's no worse than the $6500 per year I pay for insurance for the airplane, and $20,000 for the shop. Heck, look at what happened to the Frascas.
If this were my personal airplane I would not think twice about doing it myself. However, when a student/renter panics because the engine coughed and stalls the airplane into the trees right after the carb has been changed, it's sure nice to have the paperwork. Paranoid, I know, but that's what this industry has is about.

[DC Krog]

I completely understand your position. With your explaination about student pilots flying with this particular make of carburetor may I suggest getting a Marvel-Shebler MA-3. For one reason is it has an acclerator pump for the real "top gun" pilots and two you can get full product support (ie paper trail) from Precision Aeromotive. Hurry up because I heard they are vacating the Carburetor industry.

I personally like the simplicity of Stromberg carbs but you must be cautious when advancing the throttle. Good luck Greg with your business I can't imagine the legal BS you must deal with everyday. It doesn't surprise me why General Avaition has been in a decline for over the past 20 years.

[seaheli]

Precision Aeromotive was purchased several years ago by North Carolina company, Aero Accessories-Tempest-Volare.

Charles

[joea]

Precision Aeromotive was purchased several years ago by North Carolina company, Aero Accessories-Tempest-Volare.

Charles

Are they still working with the carbs? Support ok?

[smokiescfi]

I have considered the MA3SPA in the past but they have their own issues (venturis, floats, nozzles, etc.). Finding the correct MA3SPA configuration for the A65 for outright purchase is virtually impossible, and hideously expensive. It's far cheaper to pay a repair station to overhaul the Stromberg and produce paperwork than to buy a properly documented and overhauled MA3SPA. I have about 4000 hours experience instructing in, and renting, Stromberg equipped Champs with no problems. The current carb has 750 hours on it since overhaul by an out of business repair station in Texas back in 2006.

Kelly Aerospace sells the MA3SPA outright for $1824, they have none in stock, and rarely ever do. Air Suppliers is the cheapest I have found at $1494, again, they have none in stock.

[smokiescfi]

Precision Airmotive no longer owns the Type Certificate for the Stromberg and does not support the carb at all.

[smokiescfi]

Found out Aircraft Accessories in Tulsa Oklahoma will overhaul the NA-3SA1 for $650, less if the throttle shaft bushings don't need replacing. Includes stripping, boiling, machining of mating surfaces, painting, new needle and seat, Delrin or Steel, repair of float leaks, set up, and bench check.

[seaheli]

Joe,

The parent companies have had to make cutbacks to carry the investment of the Precision Aeromotive purchase. They still support their product.

Charles

[RRHaldeman]

Based on comments from experienced pilots who own and operate Champs with the Stromberg carburetor, I decided to try and find a Marvel-Schebler because it has an accelerator squirt pump and a working mixture control. Had a devil of a time but finally located a Marvel-Schebler MA-3SPA overhauled by Volare in NC (the new manufacturer who bought the Marvel-Schebler rights). It was expensive and may have been the only one for sale at the time. FYI, the new part number for a C85-12 is 10-4240-1.