MULTIQUIP GA-Series Service Manual page 30

I pull the rope and nothing happens, now what? That's a fairly simple question, but it may require more
than a simple answer. Let's take a look at the situation from a service technician's point of view. Air-
cooled engines need three basic things to run. Take away any of one of the three and it's no start
time. So, let's review these things and see if we can simplify that question.
1. The engine must be able to develop compression.
2. The engine must have ignition, better known as spark.
3. The engine must receive fuel and air through the carburetor.
If the engine cannot develop enough compression to draw fuel and air from the carburetor then it
cannot run. Normally you can feel the resistance of compression when pulling the rope. Electric start
models can be a little harder to tell without the right equipment. Keep in mind that you have to obtain a
significant amount of engine speed when you pull the rope or you will not develop enough
compression. A low battery can cause the same problem. When checking compression, use a
compression gauge. Ideally you want to see 85 pounds or more after a couple of pulls. Low
compression can be caused by a worn engine or burnt or sticky valves. Stale fuel from setting during
storage can cause even a new engine to have a valve stick in the open position.
You must have a good spark to fire the fuel mixture once it is in the cylinder. A good way to test for
spark if you don't have a tester is to take an old spark plug and cut the electrode off, so the spark has
to jump from the center to the side of the plug. Lay the plug on the engine so that it can ground and
spin the engine. If you don't have good spark check for a faulty switch or disconnected wire before
condemning the Magneto. The spark must be steady and a bright blue color.
The engine must receive a proper mixture of fuel and air, so that the spark can ignite it and start the
engine. Besides the fuel and air, the engine governor must open the carburetor throttle to allow the
mixture to reach the cylinder. A stuck throttle shaft can cause a no start, so check the simple things
first. If you suspect that the carburetor is not supplying fuel you can give a small squirt of starting fluid
into the air intake (usually with the air filter removed) and see if the engine fires momentarily. If it does
then you probably have a plugged carburetor. Once again we are back to the stale gasoline problem.
Even a good engine may not start on stale gasoline, so stick your nose in the tank and take a whiff, if
you come out gasping for air, then you'd better get rid of that fuel.
If you resolve the three problems above, the engine will run (usually). In most cases, one of these
three items will be at fault. So, next time your unit will not start, make a quick check.
M Y E N G I N
M Y E N G I N
Multiquip Inc. ◦ GA Series Generators ◦ Manual No. GAGENSM
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E W O N T S
E W O N T S
T A R T
T A R T