Help!
Thread Starter
Instructor
Joined: Oct 2004
Posts: 121
Likes: 0
From: Camp Hill PA
Help!
I just tried to start my 63 SWC after a couple of weeks. When I drove it last it ran great. This time it would barely start, blew smoke, barely ran, and when I shut it down and took off the air cleaner, it was leaking gas under the front end of the carburetor onto the engine. No one has touched it since the last ride. What happened and what is the next step? Thanks for any help you can offer.
Burning Brakes
Joined: Apr 1999
Posts: 1,162
Likes: 17
I know little about carbs, but you might have 1) dirt/rust that is allowing gas to continuously enter the bowl, 2) a float that is punctured, causing it to sink and allow gas to flood the bowl, or 3) a blown power valve, although I don't think that would cause the gas leak you described.
Perhaps one of the board's more knowledgeable carb guys can point you in the right direction.
Perhaps one of the board's more knowledgeable carb guys can point you in the right direction.
Burning Brakes
Joined: Feb 2003
Posts: 764
Likes: 13
From: Harvard MA
my guess it the you just have some dirt in valve controlled by the float that is preventing the float from doing its job of stopping the entry of gas into the front bowl when it is full.
Last edited by brucep; May 8, 2005 at 06:24 PM.
Thread Starter
Instructor
Joined: Oct 2004
Posts: 121
Likes: 0
From: Camp Hill PA
Thanks to both of you. I would be willing to take the float/bowl apart to clean out the valve if I knew what I was getting into. Is there a diagragm anywhere I can refer to or is this a job for someone that knows what they are doing. I do not want to mess up any adjustments because when it is not flooding it runs great.
Burning Brakes
Joined: Feb 2003
Posts: 764
Likes: 13
From: Harvard MA
I vaguely recall reading about a method for clearing dirt out of the float valve somewhere on this forum that did not involve disassembling the carb. You might search the archives or perhaps someone else will respond with it.
I think you need to run the bowl dry by disconnecting the fuel line so the float drops down and the value opens wide, then you reconnect the line and the rush of gas coming in through the open valve is suppose to clear it.
I think you need to run the bowl dry by disconnecting the fuel line so the float drops down and the value opens wide, then you reconnect the line and the rush of gas coming in through the open valve is suppose to clear it.
Le Mans Master
Joined: Feb 1999
Posts: 5,844
Likes: 376
From: Mobile AL
Originally Posted by rgwebb
As I recall, I floored the accelerator and then let up on it before trying to start it. Could I have jammed something open by doing that?
I would put a C-clamp on the rubber hose connecting the fuel line from the tank to the engine fuel pump. With this hose clamped shut, start the car and run it until the engine dies from lack of fuel. Then remove the clamp and re-start the car. The gas rushing through the wide open needle valve in the primary bowl will probably dislodge whatever has been keeping it from sealing.
Thread Starter
Instructor
Joined: Oct 2004
Posts: 121
Likes: 0
From: Camp Hill PA
Thanks to you all. I checked the engine this evening and there was no leakage going on. So I turned the key without touching the accelerator. It started and ran pretty rough but nowhere as bad as yesterday. I got out and checked again for leakage under the carb. Nothing. It continued to run rough while it heated to 180, but less and less so as time went on. I put the air cleaner back on and let it run for a while. The backfires seemed to get fewer and less severe as time went on.
I can only believe that I had a bunch of water in the tank, but have no idea where it could have come from. The tank was about 7/8 full of 100LL avgas so it doesn't seem possible that I could have gotten that much condensation in a couple of weeks of sitting idle - or am I wrong?
I shut it down and about an hour later took it out for about a 20 minute run. It ran like a champ! What a relief!!
I can only believe that I had a bunch of water in the tank, but have no idea where it could have come from. The tank was about 7/8 full of 100LL avgas so it doesn't seem possible that I could have gotten that much condensation in a couple of weeks of sitting idle - or am I wrong?
I shut it down and about an hour later took it out for about a 20 minute run. It ran like a champ! What a relief!!
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