Possible Holley Carburetor troubles

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Possible Holley Carburetor troubles

Post by garyf » Fri Jun 26, 2020 12:02 pm

Hi All

I have recently had rough running trouble with my standard Tiger Engine fitted with a replacement 350 CFM Holley carburetor which was fitted in around 2001.

The car was very reluctant to start (Not normal), ran very rough, wouldn't tick over and eventually broke down on me and wouldn't re-start :x

After investigation and finding nothing wrong apart from a strong smell of fuel in the Engine bay I assumed I had somehow flooded it.

After leaving the car for 20 minutes or so whilst I fetched a Gallon of fresh fuel it eventually started but again was running very rough and wouldn't tick over, I managed to limp the car the half a mile or so home and investigated further.

I still had a strong smell of fuel in the engine bay but couldn't see any leakage from the carb or fuel hoses/filter which I had recently changed.

Upon checking the oil level I was alarmed to find the dipstick showing the oil level way above the high mark!

I had somehow got about a Pint or so of Petrol in my engine oil. The only thing I could think that may have happened is I had got some muck or a sliver of rubber in the fuel system causing the Needle Valve to jam partially open?

When I broke down I mistakenly left the ignition on and fuel pump running for 5 or 10 minutes :? .

So I decide to remove the Needle valve to check it (Photo attached) I couldn't see anything jamming it and after a good spray of Carburetor cleaner it seemed to be shutting off correctly, the only thing that looked a bit iffy was the sealing 'O' Ring looked a bit shrunken?

After draining and changing the Engine oil and on replacement of the Needle valve the car started up 2nd turn of the key, ran on all 8 and was ticking over as smooth as ever once warmed up.

So, can anyone offer any advice what the problem may have been?

I've read that Ethanol can play havoc with old cars fuel systems and in particular any rubber components in the Fuel Pump or Carburetor, I've also read this modern fuel goes off a lot quicker than it used too, could it be with the Fuel being around 6 months old it had started to deteriorate?

I'm tempted to buy a rebuild kit for the Holley carb, which includes a new Needle valve and all the other components which may be affected by Ethanol in fuel, I have queried with the Holley carb technical department if all the rebuild components are Ethanol resistant and have been told they are.

Also Is it a straight forward job to rebuild a 2 Barrel Holley carb?

Any advice or comments welcomed.


Needle Valve.jpg
Needle Valve.jpg (175.96 KiB) Viewed 86 times

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