VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1916-1922 - Model 490 490 problems

Well I have been hesitant to drive the '21 the past few months. She was running beautifully for years, then I had a friend who touched the controls on the steering wheel and now it does not run right. It idles fine, but, the second you try and pick up speed it sputters. I tried adjusting the controls back to where they were to no avail. What is going on?!

The controls on the steering column are for throttle , and advance and retard of the ignition. I would have someone move the advance retard lever , and watch for correct movement of the distributor. The original distributor and generator end housing can deteriorate with age , causing them to swell up and crack, or bind together, which may be causing an ignition timing problem, either advanced or retarded ignition.

The right hand spark lever should be in the up position (retarded) for starting, moved to the horizontal position for idling, and then fully advanced (down position) for driving at speeds over 15 miles per hour.

When you are cruising at low speeds (parades, etc.), use the high ignition. It keeps the engine cool enough to stay without boiling. Be aware the fan belt must not be slippery, but firm gripping.

Well the distributor moves freely, I had it rebuilt a few years ago. The fan belt is fine it is only about 8 years old. It just seems like it doesnt want to do anything over 10 mph!

Wes, Does the engine rev out OK while you have the car out of gear and stationary. If it does rev up ok , Then i would check for binding brake shoes or something else than the engine.

If it doesn't rev out OK , then it might be a fuel blockage at the carburetor.

Wes,

The Zenith 04 carburetor has a fuel screen on the bottom of the carburetor where the fuel line attaches to it. It may be partially plugged up. Of course over the many years someone may have removed this screen so don't be surprised if it's gone, but I would check it first. How old is the gas in the tank?

Gary

The 1921 model 490 originally had a T4 Zenith carburetor with a cast iron body for the main riser/ throttle area and are prone to cracking vertically. I would check to see if yours has cracked if you have the cast iron T4 still fitted.

The earlier O4 Zenith carburetor was used up to 1919 and has a full bronze (brass?) body .

my 21 acted up a bit the other day. It was dirt in the Screen and since there was a small rip in the screen some dirt got into the jets. In that case pull the two half inch hex head plugs and blow out the holes up in the carb body with very low pressure air(like a computer duster can) or carb cleaner. I got lucky and just let the fuel flow and the crud came out. All is good now.

I have not had time to look at it, so, I should pull apart the carb and take a look inside? The engine seems to rev ok, it is a strange car! Very different from everything else I have!

Wes_W.

I would also look at putting the rear axle on jack stands ,put the gearbox in neutral , and spin the back wheels,and see if all is free with the brakes, drive shafts and axles, differential etc.

You don't have to pull the carb off, just unscrew the fuel line and the fitting at the bottom of the carb 5/8th hex and the 2 1/2 hex head caps. The jets are up inside the holes of the 2 hex caps. I also like Jack 39s idea also and put it in gear (not running) to see if the clutch is slipping.

Ok, I opened up the top and bottom of the carb and cleaned a bunch of junk out of the carb! I have not had time to test the car, as the battery is for some reason not good now (have to get an Optima!). Anyway, the screen is still in place and looked like new, I cleaned all of the parts and re-installed them and ran the car for a bit. The gunk was sandy and gooey...

To all having trouble with "polluted" gas: From many sources there are reports about the "new" gasoline wit addition of ethanol. Among other bad behaviours the additive loosen up f.ex. the surface of a tank sealer or other layers on the inner surface. When you fill gas use the one with as little ethanol as possible, whatever the oilcompany tries to tell you.

Since the carb had crud, now take the fuel line off the carb and let the tank drain through a filter medium like a coffee filter. then use a syphon hose to remove all the rest of the cruddy gas from the bottom of the tank. There is a short pipe sticking up from the bottom of the tank that helps catch the large stuff so be sure to get around that pipe also. Use a flashlight to see how clean the tank is. The gooey crud could be just old gas varnish or it could be failed gas tank sealer. If you can scrape out a sample then use different chemicals and see what cuts it so you can have a clean tank.These gas tanks are made of what is called "tern plate steel" which I think may be just lead plated steel and soldered together. Don't use a chemical that will damage the plating. Chlorinated Gumout carb cleaner may go far to cutting the crud. White gas, acetone, and other things like that may be a place to start. Acids will ruin the plating.

I looked inside the tank and it looks fine. I have been putting new gas in every few months for years. I have a feeling the buildup was over many years in the carb, it does not look like it had ever been opened.