Clean the carbs

**Richard2** · #1 (**permalink**) 08-20-2006, 08:28 PM

Further to the problem with #1 cylinder not firing, I replaced the plug and changed the wire to #1 with no improvement, ie: pulling the wire off #1 makeds no difference to thye rough running. When I pull 2,3,4 off one at a time it almost dies. So I want to look at the carb. Are the jets under that little cap with the wing nut holding it on? Are they easy to remove and clean? Any suggestions?

**velocedoc** · #2 (**permalink**) 08-20-2006, 08:42 PM

Yes, the jets are under the cap with the wing nut. Pull them and the jets are on the bottom. The air correctors are on top. The emulsion tubes are in the middle that hold the two parts. A good screwdriver is all you need to check the jets.
If the jets are clean, then you have a plugged idle circuit. That means something has gotten in the little passage that goes from the main bowl to the idle circuit exit behind the throttle plate. Sometimes if you unscrew the idle screw you can use carburetor cleaner to blow out the passage. Just besure to wear eye protection as the cleaner can blow back in your face when you squirt it.
Be sure you remember how many turns you made when you remove the idle screw so you can put it back at the same place.
Sometimes carbs that sit around for a while get a white gunk inside the carb bowl and it plugs things up.
If that doesn't resolve the problem you will most likely have to have the carbs rebuilt (dipped in cleaner and new gasket kit) and then have the carbs reset.

**Bill S** · #3 (**permalink**) 08-20-2006, 09:07 PM

Just to be absolutely certain that you don't have something like a crack in the distributer cap, hook your timing light to wire #1 and verify that plug is firing. If it is, proceed to the carb with Christopher's suggestions.

Bill Sinclair

**Richard2** · #4 (**permalink**) 08-20-2006, 10:30 PM

Well, I can do that again. Something might have happened, but when I put the head on, I used the timing light to set the timing. I got a signal. I pulled the #1 wire off the distrib cap and could see a spark as I slowly moved it close to #1 hole in the cap. I also bought one of those el cheapo razor looking devices from Schucks and got the light to blink when I held the end on the plug as per the directions.
I had soaked the carbs in some gas to clean the dirt off the outside and think that may have gotten some dirt in somewhere.

**Richard2** · #5 (**permalink**) 08-20-2006, 10:30 PM

I think there's an internal filter somewhere I should check also

**velocedoc** · #6 (**permalink**) 08-20-2006, 11:24 PM

There is an internal screen filter on the fuel inlet, might want to check that to see if its plugged with dirt, but that dirt would have to get by the fuel filter before the carbs. Most likely the dirt or what ever is in the bottom of the fuel bowl. The only way to check that is to remove the top of the carburetor and that can be done on the car with out removal.

**Richard2** · #7 (**permalink**) 08-21-2006, 07:40 AM

To remove the top, I should have a new gasket on hand, right?

**velocedoc** · #8 (**permalink**) 08-21-2006, 10:19 PM

Not really, unless it has been a very long time since the carb was last rebuilt. Most times you can just put the top back on and it will work just fine. Just don't over tighten the screws!

orden · #9 (**permalink**) 08-23-2006, 05:13 AM

The float chamber feeds both no 1 and 2 so the inline filter is ok. I would try to spray WD40 into no 1 intake with engine running and see if no 1 comes to life. If it does not then back to electrical side, and check compession on 1. It seems unusual that no 1 won't fire at idle and through the rev range as the fuel delivery changes path. Just my 10 cents worth.

**papajam** · #10 (**permalink**) 08-23-2006, 06:00 AM

One thought that comes to mind is that if cylinder #1 misses only at idle but seems to fire under load, would be to check the vacuum port fitting on the #1 intake runner just above the distributor. If there's a hose on the fitting, is the hose in good condition and hooked up to the proper fitting at the other end? If there's a cap on the fitting, is the cap in good condition? If the fitting is open to atmosphere, you've found the problem.

**Richard2** · #11 (**permalink**) 08-23-2006, 07:50 AM

Oooooops. There's no hose on the vacuum fitting, and I took the fitting out to plug the hole but forgot to when I was assembling it. Thanks for the reminder. I'll plug it and give it a try this evening.

Little Italian · #12 (**permalink**) 08-23-2006, 07:22 PM

Good catch Papajam!

Just a little reminder about removing the jets/emulsion tubes. When you screw out the e-tube and jets, they are held in a small cap that slides over to top of the air corrector. That cap is called the emulsion tube holder and has a couple of small slits in it. Some times these need to be bent in a tiny bit to make the holder snug in the top of the E-tube and air corrector. Before you reinstall the holder and e-tube assembly, partially (slightly) pull the E-tube out of the holder and then screw it back in to the carburetor. As the E-tube holder assembly is screwed in, it will now seat the main fuel jet on to its seat down in the bottom of the Emulsion Tube well. Otherwise, it could be too loose and allow too much fuel into the carb, thus fouling the spark plugs. Good Luck!