My 55 Mercury now resides at 7000 feet altitude. The plugs are sooty and black after just a few miles. I am thinking I need to tune the carb for the much higher altitude and thin air. Any tips fellas?

My wife said she would divorce me if I bought another car. It scared me so bad I only bought 3 last month!

55 Monterey:

I have a copy of a service bulletin from Ford about the '55 Ford at different altitudes.  I assume Merc would be similar.  For 0 to 5000 feet, .050 primary and .086 secondary.  For 5000 to 10000 feet, .048 pri and .081 sec.  For 10000 and up, .046 pri and .073 sec.  So I would say go .002 smaller on the pri and .005 smaller on the sec. jets.  No problem on the primary, 4150 style Holley carbs jets will fit.  Secondaries are a problem, haven't been available for 20+ years.  I have soldered the holes shut and drilled them the size I need.  If you don't get in to the secondaries very often, they probably are not an issue on your car.

Now, about the black plugs.  Here in Indiana, when MTBE was banned from gasoline, the legislature quietly legalized the use of up to 10 percent alcohol in our gas.  It fouls the plugs on my low compression Model T and farm tractor in short order.  I haven't found a way to stop it yet.  Maybe you are getting a lot of alcohol in your gasoline too?

John

John - "The Hoosier Hurricane"

With clean, fresh plugs it always starts with just the slightest touch of the key. But let those plugs get boogered up with black soot and she cranks embarassing long before firing.

Actually, I have heard of many problems with tuning the carb and the potential for fires. I am thinking it be best to swap carbs using an adapter plate. Any thoughts here?

My wife said she would divorce me if I bought another car. It scared me so bad I only bought 3 last month!

55 Monterey;

I bought a spare Holly 4000 from Pony. Big $, and I had to send it back once for some fine tuning, but I am very happy with it's performance. If you still want a stock distributor/engine and can live with the extra cranking needed to prime a cold teapot (traditional flaw), you might discover that when properly set-up (tell them your situation), it does the job nicely. The Pony runs much stronger than my other carb which was rebuilt locally by a very experienced, old-time Ford mechanic.



John;

Do you live near a city where the gas is altered for pollution control? The remote rural Indiana stations where I fill-up all swear no alcohol in gas. Are they lying?



P.S. I have to log-in every day ("remember me" is checked). I have the same trouble with eBay. My connection is dial-up and I wonder if DSL people have the same problem with the new software?

6 VOLTS/POS. GRD. NW INDIANA

Daniel, My problem is not starting a hot or a cold engine because if the plugs are nice and clean it will start immediately. My T Pot is running too rich and sooting up the plugs. The jetting may have been correct for where the car used to reside, but now it is high in the mountains and the thin air is causing fits.

My wife said she would divorce me if I bought another car. It scared me so bad I only bought 3 last month!

Daniel:

I buy my gas for my vehicles, when I am not travelling out of town, in Muncie.  All the Muncie gas comes from a common supplier, except for a couple "low price" (??) places that get theirs directly from a refinery in Indianapolis.  Anyway, they won't admit to any alcohol being added, but most stations don't know, as I said, the politicians sort of secretly changed the law.  The station operators say that if they have 10 percent alcohol, they have to post it on the pumps.  Old law.  Who supplies them with the stickers?  Why, it's the gasoline suppliers, who are not required to publish the information.  One of these days I'm going to mix some water with some gasoline, shake it up, and let it set a few days.  The alcohol and water will combine, and I can draw the gas off the top.  Then I'll drain a tank and fill it with the washed gas, and see if the carbon problem disappears.  I have a friend in northern Indiana that has had a few failures of the accelerator pump in his teapot.  They swell up and stick in the bore.  I'll bet it's alcohol.

John

John - "The Hoosier Hurricane"

Me thinks Mr. Hurricane is onto something here with the alcohol problem. My plugs are not wet at all from an overly rich condition. The plugs build up a powdery blackness that will just blow off with compressed air. It is almost like having a charcoal dinner then blowing a nice dry carbon fart.

Me has an idea. What would ya'll think about a rigged up water injection system to periodically clean the plugs? Here's why I asked. After thinking about this problem and closely looking at my sooty plugs, I slowly poured a teaspoon or six of water directly into the carb as she was running. I pulled a couple of plugs and they were shiney clean...nothing like before the water was "injected". I am aware that years ago there were water injection systems on the market just for this purpose. I guess it wasn't very popular then but I think I have found a need for one now.

All thoughts are appreciated.

My wife said she would divorce me if I bought another car. It scared me so bad I only bought 3 last month!

Monterey:

Actually, I have installed a primitive water injection on my farm tractor.  It is a needle valve screwed into an existing port in the manifold, fortunately in the center, and a piece of vacuum hose to a gallon milk jug with water.  Under light loads, I open the valve slightly and it keeps the plugs cleaned of the dry carbon you are finding.  Under heavy load, I close the valve, the combustion heat under heavy load keeps them clean.  Years ago my brother-in-law used one of those kits on his big block chevy pickup.  After a year, the exhaust manifolds began to develop cracks.  He took them to a weld shop, and they told him the cast iron was "burned up" and would not weld.  Had to buy new manifolds.  Took the water injection off.

John

John - "The Hoosier Hurricane"

Mr. Hurricane, What would you think about just using the water injection only before shutting off the engine? It would appear to me that it would clean the plugs and facilitate a quick restart. Other than the lag in starting with sooty plugs, she runs fantastic. I was thinking along the lines of a simple primer bulb to shoot a little water into the manifold. Nothing too complicated.

As always, your thoughts and expertise are appreciated.

My wife said she would divorce me if I bought another car. It scared me so bad I only bought 3 last month!

Monterey:

That should work, as long as you run the engine long enough after you give it a drink to ensure that there is no moisture left in the intake system or, God forbid, a cylinder to cause rusting.  Probably not a problem is the engine is fully warmed up before shutdown.

John

John - "The Hoosier Hurricane"