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Do needle and seats go bad and stick closed?

Posted By: Ramrod39

Do needle and seats go bad and stick closed? - 12/29/12 02:02 AM

Got a Rochester 2 barrel on a '68 Brand X I've had stored for a while. Car ran fine when I parked it. Went to roll it out and couldn't get any fuel into the float bowl....needle and seat not letting fuel in.

Pulled it apart, cleaned the needle and seat (they looked OK), checked the operation on the bench by blowing in the fuel inlet line and it seemed good. Put it back on the car, no start. Needle and seat stuck again. Blew a little compressed air in the fuel inlet line, re-hooked up the fuel line and it ran for maybe a a minute. Then no fuel to the bowl again. No problem with fuel pressure.

Anybody seen this before? The needle and seat and all of the carb internals look pretty good, not gummy.
Posted By: MoparforLife

Re: Do needle and seats go bad and stick closed? - 12/29/12 02:45 AM

Old gummy gas in system
Posted By: RapidRobert

Re: Do needle and seats go bad and stick closed? - 12/29/12 02:55 AM

If you're sure nothing is rubbing/hanging up mechanically on the float assy then blast the needle/seat with a shot of starting fluid to clean it. If the needle comes out seperately wipe the neoprene tip of it with your thumb to polish/clean it. Are you sure the pump is priming/gas is being delivered to the carb inlet?
Posted By: 500ciDuster

Re: Do needle and seats go bad and stick closed? - 12/29/12 02:59 AM

I second the bad gas, few years back I was junkin some of my stuff and was mixing old gas in my truck just to get rid of it anyway I hit a bump on a crappy road which jammed the needles shut and they stuck shut then the truck died
Posted By: hp383

Re: Do needle and seats go bad and stick closed? - 12/29/12 03:18 AM

You will probably find shellac or gummy gas in the bottom of the float bowl(s) as well.

A good disassemble and cleaning with carb cleaner wouldn't hurt. Or if you have the time and funds, toss in a rebuild kit too.
Posted By: Ramrod39

Re: Do needle and seats go bad and stick closed? - 12/29/12 06:13 AM

Quote:

You will probably find shellac or gummy gas in the bottom of the float bowl(s) as well.

A good disassemble and cleaning with carb cleaner wouldn't hurt. Or if you have the time and funds, toss in a rebuild kit too.




Funny thing is, none of the gas seems gummy or seems to have shellac. Bottom of the bowl looks OK. I sprayed the needle and seat with carb cleaner and figured that world take care of it. Wrong. I guess I'll buy a kit and throw the new needle and seat in.
Posted By: bobbyb

Re: Do needle and seats go bad and stick closed? - 12/31/12 03:24 PM

I had a little problem with my boat motor carbs. I removed the bowls and could see trash in the bottom from alcohol/gas. I cleaned up the carbs and a rebuild kit, but the kit didn't have needle valve. Installed carbs and still had a problem, bought a new kit with new needle valves and fixed the problem. Old needle valves didn't look that bad, but I guess they were bad enough to cause a problem.
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