Caruretor

[Ray]

Ok guys I need some more help, after a 2 year restotation the plane is flying and flying well with exception to the engine which is also running well however my plugs are sooting up, all of them. The current carb is a stromberg S3B with no leaning option. I have been told there is a better stromberg carburator and was wondering if anyone had an extra one for sale or the numbers needed to get a rebuilt one. Not sure what the cross reference number is so any help would be appriciated. I was told the problem is the seat on the float needle delivering a little extra fuel. I have priced this out with gaskets and its about 150.00 and with what I have been told about the problems with this carb is it worth buying a newer stromberg? Thanks

[M Towsley]

Re: Caruretor

Ray,

The problem you run into is sometimes the carb you have may not be for the 65 hp engine as someone over the years may have changed the jets and venturi. You really don't know until you take it apart. It you think it is just the float level, this can be very time consuming and aggravating to do....especially if you have never done it before. I have set the float level on four or five of these little carbs and it is super time consuming to do. Plus, you really have to have the parts and tools and bench setup to do it right. I would highly recommend sending it away and having it done professionally. You can do a search on here to find someone who does it, a buddy of mine just had his done as we found the carb was setup for a completely different Continental engine. There is a guy in the Chicago area who does it but his pricing is astronomical for the rebuild. The one my friend had done was sent out to maybe California. I will try and remember to check with him.

Oh, and a couple of other things. The mixture on these really only work above 5,000 feet. It is not like the normal mixture you would be used to on other planes. Once you get the carb setup to run, they are good little carburetors that, for me, never give me a problem again.

Update, this is the guy:

Kevin Peterson
KPS Airmotive
26524 Ruether #613
Santa Clarita, CA 91350
661 492-3234

[cvavon]

Re: Caruretor

RAY AS MARTY has said the carbs are about fool proof if you don't have fuel running out all over then the float is working my guess is some one has tried to make it a carb for a 75 hp or larger and put in a larger venturi or main jet the main jet is the first place i would look and don't trust the number stamped on the jet as they are easy to drill check it with a number drill bit that is the size that it's suppose to be the venturi is 1 1/4 in for a 65 and the jet is .49 don't mess with the float if it is working as Marty said they are a real pain if you have any more questions call me 931 306 9484 chuck

[NY86]

Re: Caruretor

The mixture on these really only work above 5,000 feet.

I hear this all the time, but it's bit misleading. The mixture works fine at any altitude, but the carb is reasonably self compensating, so there is no improvement available from the mixture control until you get to about 5000 ft density altitude.

[Ray]

Re: Caruretor

OK its not leaking any gas but why would my engine be running so rich then? When I took the engine down it was running excellent with exception to a few oil leaks now every plug is black, not oil black but soot black that tells me it is running rich. Could there be any other reason other than the seat is not woking well.

[M Towsley]

Re: Caruretor

Ray,

When you said you took the engine down, did you rebuild it or just remove it? Intake obstruction, carb heat box shutter not opening fully??? Mixture screw too far out?

John,

Exactly, I had them hooked up on two of my other T-Crafts. It works, just slowly and at altitude. It takes a steady tach and patience to use it well. Rarely does my plane get above 2,500 msl, about 1,900 agl.

[Guest]

Re: Caruretor

If I follow this (and I am not sure that I am) the carb has not been repaired or modified.

The engine operated fine before the airplane was worked on but now the engine seems to be running rich.

So then I suggest that you check your primer if you have one. Does it leak fuel into the mainfold? are the o-rings bad?

Dave

[M Towsley]

Re: Caruretor

Dave, good one. I forgot to fully close and lock the primer on my L-2 and it did the same thing as it was partially open and pulling fuel.

[cvavon]

Re: Caruretor

also if he replaced intake hoses old hoses could have been leaking causing lean mixture

[Ray]

Re: Caruretor

No, I did not do a thing to the moter but I did replace the primer but its new, strange that would cause a problem but worth looking into.

[Guest]

Re: Caruretor

Ok guys I need some more help, after a 2 year restotation the plane is flying and flying well with exception to the engine which is also running well however my plugs are sooting up, all of them. The current carb is a stromberg S3B with no leaning option. I have been told there is a better stromberg carburator and was wondering if anyone had an extra one for sale or the numbers needed to get a rebuilt one. Not sure what the cross reference number is so any help would be appriciated. I was told the problem is the seat on the float needle delivering a little extra fuel. I have priced this out with gaskets and its about 150.00 and with what I have been told about the problems with this carb is it worth buying a newer stromberg? Thanks

If the needle valve is leaking the carb will drip fuel from somewhere if you leave the gas valve open for a long time (1-20 hours).

Try leaving the fuel valve open over night and see if you discover a drip.

Dave

[M Towsley]

Re: Caruretor

Just because it has a drip doesn't necessarily mean it is going to run rich. The needles and seats in most of these have probably been switched over from the old neoprene to stainless or nylon. The stainless needles, unless carefully lapped, will cause a drip.

[Guest]

Re: Caruretor

That's a good point Marty.

But if it does not drip then the needle and seat are for sure not cuasing it to run rich.

So this test will clear the needle and seat of suspicion if the carb does not drip.

Dave

[Ray]

Re: Caruretor

I have left the fuel valve on for months without a single drip of fuel so maybe it's the primer. I do notice everytime I use it though I have to pump it several times to get fuel in it and to the engine. If it was drawing fuel through it would it not stay full of fuel and not need several stokes to even get the fuel to draw?

[3Dreaming]

Re: Caruretor

What kind of fuel are you running?