Stromberg maintenance question.

[VanDy]

Quick backstory.. Grandpa has owned this Tcraft since '77, I've been sole mx on her since 2012. Before that is was all grandpa and his IA.

Couple months ago when it started getting cold I had a but of a stutter at 1300-1400 rpm, above or below that it ran great. So I backed the idle mixture screw out 1/2 turn. Ran fine, even did my commercial checkride in the Tcraft. Showed back up this weekend. Gave it another 1/2 turn back to see if that would help, it didn't. So I'm suspecting a blocked bleed port in the carb. I pull it, split it and find this.... I pull the bottom drain every annual and let fuel flow for a few seconds to clear it out. Apparently that isn't enough. What is the tribe doing for this on their strombergs?

[M Towsley]

Re: Stromberg maintenance question.

As you see, the drain is higher than the 'sump'. Not sure where that design thought came from. I let if flow for more than a few seconds and then check the contents of the container to see if anything is in it.

Are you checking the gascolator, is there a good screen in it? I found my screen wasn't fitting well a few years ago which probably allowed a chunk of something to block the idle circuit.

Are you using 100LL or MOGAS? I filter all my fuel through a Mr. Funnel, (except anything I buy at an airport that goes directly into the tank, which isn't that often).

After having the engine die twice on final the same day, (above referenced idle circuit issue), I am very careful about what goes in the tank.

[VanDy]

Re: Stromberg maintenance question.

I don't think that I ever actually caught anything and looked at it, but I certainly will now. I will also let it flow long enough for at least 10 seconds through a white handkerchief or similar. My gascolator screen for the last 2 years is foe the Tcraft Supply Company, and fits really well. I honestly think the sediment may be from my cork float, so I'm going to change that out with the ford equivalent while I have it all part too.

It is possible some ethanol could have gotten in there,
But since I've been flying it, it has been 100ll with mmo added every tank.

As you see, the drain is higher than the 'sump'. Not sure where that design thought came from. I let if flow for more than a few seconds and then check the contents of the container to see if anything is in it.

Are you checking the gascolator, is there a good screen in it? I found my screen wasn't fitting well a few years ago which probably allowed a chunk of something to block the idle circuit.

Are you using 100LL or MOGAS? I filter all my fuel through a Mr. Funnel, (except anything I buy at an airport that goes directly into the tank, which isn't that often).

After having the engine die twice on final the same day, (above referenced idle circuit issue), I am very careful about what goes in the tank.

[M Towsley]

Re: Stromberg maintenance question.

I have had the synthetic cork in this and my prior BC-12. I ran across my first BC-12 last year and the synthetic had not deteriorated at all. I am unsure how old it was as it was already on the float wire when I bought it ten years prior.

Two of these: http://www.snydersantiqueauto.com/2450 Or you can salvage one from an old fuel tank. They come in different styles but these are similar in size to the cork ones.

Some discussion in the past about legalities, so be aware, but this stuff is made to be in fuel and does not break down. Same stuff in modern vehicles, even those with E-85 flex fuel.

[VanDy]

Re: Stromberg maintenance question.

I recently put one of these In a Tcraft with good results... Will most likely so the same in mine http://vb.taylorcraft.org/showthread...OAZ%2F9202%2FB

[M Towsley]

Re: Stromberg maintenance question.

I bought those too, never used them. The synthetic cork is easier to deal with, the wire runs right through them like stock.

[astjp2]

Re: Stromberg maintenance question.

Get a real gas cap for a J3 from Univair. I have tried 3 different caps, the brass ones have a tendency to split when you get them above 6K MSL. That is why the Marvel carb no longer has a brass float, they are some epoxy formulation. You have no idea what goes through your mind when the float drops, I had a cork one do it and I was in the middle of no where. For the $90 that it used to cost from Univair, its well worth the money and is a real airplane part. Tim

[VanDy]

Re: Stromberg maintenance question.

Get a real gas cap for a J3 from Univair. I have tried 3 different caps, the brass ones have a tendency to split when you get them above 6K MSL. That is why the Marvel carb no longer has a brass float, they are some epoxy formulation. You have no idea what goes through your mind when the float drops, I had a cork one do it and I was in the middle of no where. For the $90 that it used to cost from Univair, its well worth the money and is a real airplane part. Tim

That would get your attention for sure!

[fcairmotive]

Re: Stromberg maintenance question.

I own a Accessory shop and FBO in AK.

I have overhauled and repaired many Stromberg carburetor over the years. The first thing I do is an inspection of the material, dried and on a white sheet of paper.

I inspect the "stuff" with a 10 power loop and also take pics with a 16 megapixel camera for the customer to see and blow up on the computer. A very handy tool. In this way I can determine what the substance is and then correct the contamination problem. Usually it is either rust from a drum or flakes of sloshing compound from attempts at sealing up a seeping tank years ago.

In order to get the stuff out you will have to disassemble it some. The gaskets are still available from Spruce, PN 07-02200. As far as draining and flushing the carb the way you describe, it is almost impossible to get that debris out because of the way the fuel comes into the carb. If you follow the fuel it comes up out of the seat portion of the float valve and burbles over it and never "flows" to the other side of the carb and out the drain. You must do what you did and disassemble and clean it. Its pretty easy to inspect the float in the tank for missing pieces.

One of the ways I seal the indicator float is to coat it with Flamemaster CS 3204 Sealing Compound. Completely impervious to all fuels. Hope this helps some. By the way my first T-cart I bought was in 1974, N96139. I now own a F-19 on wheels, a F-21 on floats and two for BC-12D's for parts or restoration.

[Robert Lees]

Re: Stromberg maintenance question.

Hello fcairmotive, and welcome!

I hope you will not be offended, but I have added some double-paragraph spacing to your original post to make it easier to read.

Rob

[VanDy]

Re: Stromberg maintenance question.

Thanks! I was wondering what people used to seal their cork, I have a 'new' one from the antique car guys.

I own a Accessory shop and FBO in AK.

I have overhauled and repaired many Stromberg carburetor over the years. The first thing I do is an inspection of the material, dried and on a white sheet of paper.

I inspect the "stuff" with a 10 power loop and also take pics with a 16 megapixel camera for the customer to see and blow up on the computer. A very handy tool. In this way I can determine what the substance is and then correct the contamination problem. Usually it is either rust from a drum or flakes of sloshing compound from attempts at sealing up a seeping tank years ago.

In order to get the stuff out you will have to disassemble it some. The gaskets are still available from Spruce, PN 07-02200. As far as draining and flushing the carb the way you describe, it is almost impossible to get that debris out because of the way the fuel comes into the carb. If you follow the fuel it comes up out of the seat portion of the float valve and burbles over it and never "flows" to the other side of the carb and out the drain. You must do what you did and disassemble and clean it. Its pretty easy to inspect the float in the tank for missing pieces.

One of the ways I seal the indicator float is to coat it with Flamemaster CS 3204 Sealing Compound. Completely impervious to all fuels. Hope this helps some. By the way my first T-cart I bought was in 1974, N96139. I now own a F-19 on wheels, a F-21 on floats and two for BC-12D's for parts or restoration.

[astjp2]

Re: Stromberg maintenance question.

You do realize that the sealant could cost more than a new univair fuel cap for a J3? right? Dump the cork one and get the one from UNIVAIR, its worth the money. I am not shittin ya, it is absolute terrifying when a cork sinks, had 2 from wag do it. That is why I went with the univair composite one. Tim

[N96337]

Re: Stromberg maintenance question.

Welcome Fcairmotive! Your first Tcraft wasn't too far from mine in number...96337. At one time 336 was up there somewhere too. Glad to have your experience here! Good to hear about a good sealant!
John