How to Start an Engine That's Been Sitting

Most of us will need to know how to start an engine that has sat for a while...

Many of you will get a hotrod with an engine that hasn't been run in a long time. Some of you simply have an engine that hasn't run for years.

Most of the time you have heard "It's supposedly rebuilt," or "It was running great when we quit driving it..."

Well, you really don't know what you have till you either run it or tear it down.

So, let's see if we can get it running!

First, pull the plugs. How do they look?

If the insulators all look kind of tan and in good shape, things are looking good.

If there is lots of black goop or lots of crud all over them, it's probably an indication of either bad maintenance or it could be burning oil.

Squirt some oil or Marvel Mystery Oil into the cylinders. A few tablespoons apiece should do it. A small piece of tubing stuck on the end of a small funnel works well. Let it soak while you work on a few other things.

Now check the carb. It's great if you have a good clean one you can switch out for the old one but that's not always possible. What you don't want to happen is suck nasty stuff from the bowl through the carb.

If it's been setting a looooong time, it's usually best just to rebuild it. Especially if the air cleaner hasn't been on it. If all the gaskets are dried out and split it may end up acting like a sprinkler!

This is a good time to remind you: Always have a fire extinquisher handy...

If the carburator hasn't been setting too long it might be ok. If it doesn't look too bad, then try it. It's best if you can pull the airhorn assembly off to see in the bowl, but you run the risk of tearing the gasket.

If the fuel in the carb smells like varnish, the rest of the fuel system is also gunked up. If this is the case or you are starting up an engine out of the car, you need to rig up a little fuel system of your own. Use a small gas can and a hose and hook it up to the fuel pump on the engine. Be sure and tie it out of the way of the engine or anything that could hit it or spark near it.

If the air cleaner hasn't been on it or if there are a lot of open holes, stuff may have gotten in it. Pull the carb and look down into the intake. If you see anything, pull the intake off and clean it out and look down into the intake ports of the heads.

Now put all that stuff back together. Leave the plugs out though.

Now let's change the oil and filter. When you have the drain plug out, stick a finger, screwdriver, stick, etc. up in the hole and see if there's a big layer of goop in the pan. If there is, you may want to clean the pan out first as you don't want to plug the oil pump and run the engine dry.

It's time to see if the motor will turn over. First take the distributor cap off so you can see the rotor. Now take a breaker bar and socket and get on the crank bolt and see if you can turn the motor over by hand.

Watch the rotor. If it turns with the motor, that's good. If it lags behind a little bit when you turn the motor, the timing chain may be worn out which indicates lots of miles.

You're just seeing if the motor is stuck. Don't turn it over and over, just a complete revolution. Now put some more oil in the cylinders. Turn it again. Did the motor seem to turn over smoothly? You might feel some resistance, but what you are looking for is something stuck or binding.

Now the cylinders should be lubed up. Turn the motor one more time pushing the excess oil out.

Put the plugs back in. If the old ones couldn't be cleaned, put in new ones.

Now let's check the ignition. Are the spark plug wires ok? Look in the distributor cap. Clean any corrosion from the terminals on the cap and also clean the rotor. If you have points, make sure they open and close, the gap is close and the contact points are clean. Replace the condensor. They are cheap and they are the culprit alot of the time for engines not starting that have been setting awhile. If the coil is suspect, then replace it with a good one or get a new one.

Now we'll mention something on prelubing. That is, manually turning the oil pump to push oil through the engine like it would if it were running.

This is one of the biggest savers of engines if your engine is capable of doing it. A few oil pumps operate differently, and doing it is not practical. Most engine oil pumps however can be operated with a tool or old modified distributor. You can usually buy the tool for cheap at auto parts stores, catalogs, etc. You can also modify an old distributor that fits your engine. Grind the teeth off the gear or remove it and remove the stuff on the top leaving the shaft sticking out enough to get a drill on.

Use a big drill, preferably half inch. You don't have to spin it fast. You have to spin it in the same direction the distributor spins. Do it until you see oil pressure on the gauge. If you don't have a gauge, pull the rocker cover(s) and spin the pump till you see it come out by the rockers.

Some people will spin the drill some, turn the engine over 90 degrees by hand, spin some more, turn the engine again, spin, turn, etc. until the engine has turned over twice.

Now the engine is ready to be spun over with the starter.

If you can't prelube, then turn the motor over with the starter (without pumping the gas) until the oil pressure comes up. You're not trying to start it yet.

Don't use starter fluid or pour gas down the carb. That's very hard on engines and can tear the motor up before you even get it started.

If there is fuel in the carb bowl, it should start and run long enough to pull fuel through the system. If there isn't, you can get fuel into it through the vents. Just use an eyedropper and squirt the fuel down the vent filling the bowl. Usually about a few teaspoons worth.

Quick overview...

-Oil down cylinders and make sure it turns over by hand.

-Change fluids and hoses.

-Make sure carburator and fuel system is good to go.

-Make sure ignition is in good shape.

-Prelube if possible.

Now fire it up!

Listen for any noises that shouldn't be there. If there is, shut it down and find out what it is.

The engine may smoke for a while. This is normal.


Some engines will start right up and be perfect after not being started for 25 years and setting outside in a puddle. Some engines may blow up after starting them that have sat for 2 years in nice dry storage. It's kind of a roll of the dice. There are so many variables and little things that can go wrong when you start an engine. Hopefully this article will help eliminate some of those and make your engine start up successful!

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