Caruretor

[barnstmr]

Re: Caruretor

Try Ted VanLandingham

Re: Caruretor

I am betting on the primer needing o-rings and/or not clsoing off the check valves.

Easy test, disconnect the primer, be sure to plug all holes.

I think if you had an 1/8" pip cap and plug you code take the primer injector out of the intake manifold and put the plug in there then put the cap on the primer injector.

Dave

[NY86]

Re: Caruretor

The primer certainly could be the issue.

If you did nothing to the carb, then maybe the air bleed passages are clogged. A leaky needle and seat won't usually make it run rich, except sometimes at idle, unless it's leaking so badly it would be dripping all over the place.

Does it puff black smoke at idle?

[Ray]

Re: Caruretor

100 low lead and a little mogas alcohol free

[M Towsley]

Re: Caruretor

Ray,

That may indicate something. If the o-ring is bad it could cause fuel to leak by, (I think). If it is not in the locked position fuel can be drawn past the primer piston and fed through the primer nozzle into the engine. From what little experience I have when I looked at a disassembled primer it it a simple piece. (Can't tell that from the prices, though)! There is an o-ring on the piston and a check valve ball that opens when you pull the primer handle out to fill it. Then, the ball closes the primer intake line allowing the primer fuel to travel down the primer line to the nozzle in the engine's intake. Normally when you pull the primer out you wait for a few seconds to allow it to fill, you can sometimes hear it. Then you push it in. If you have to pump it to get any draw the o-ring may be tired. But still, Dave, brought up a good point that it could be coming through the primer. What you described is exactly what happened to me with my L-2's primer.

[3Dreaming]

Re: Caruretor

What kind of fuel are you running?

[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?

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

[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.

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

[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.

[cvavon]

Re: Caruretor

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

[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.

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

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.