Small engines can be purchased for many self hobby types. Places like Northern Tool are great for small engines anywhere between one horsepower to 23 horsepower engines. These engines are purchased for many projects like water pumps, go carts, homemade generators, log splitters and various other projects. Pay attention to your project before purchasing an engine. Some projects require verticle shaft engines where others need horizontal shaft engines. The engine configuration generally will not interchange with the others. You will probably need accessories also to couple the engine to whatever drive system you use. Generally the same store, such as Northern Tools, will have sprockets, and drive shaft coupling parts to connect to whatever parts and components that need to be driven. If you plan to make a go cart briggs and stratton and tecumseh both have race cart series. It would make sense to use the same engine so that you have all the same aftermarket parts available to you. If you plan to build a generator make sure the engine has a good governing system to control the engine rpms. A generator engine should be run around 3600 rpms to keep the cycles at 60 hertz as regular ac power.
Two and four stroke outboards are more similar in terms of performance and efficiency than ever before. Four strokes have become far more lightweight with more power than before. Two strokes have become far more fuel efficient while keeping their excellent power to weight ratio. Some companies such as mercury marine have produced four stroke engines with supercharging and intercooling to increase power with minimal increase in weight. Many other companies such as johnson stand firm in the belief that two strokes are still the best engine configuration to use. Most companies still offer two strokes while newer models are four stroke. All outboard companies accept the fact that the four strokes weigh slightly more. Most consumers don’t seem to mind having a little extra weight for four stroke technology that is far more common in today’s engines. Unfortunately with lightweight four stroke technology comes a hefty price tag also. People that have businesses of chartering fishing trips or that log high amounts of hours on their engines may see an advantage using a slightly more fuel efficient motor. Most boaters will never see enough of an advantage to regain the cost difference of a four stroke engine or possibly even a direct injection two stroke. The alternative being fuel injected two strokes or possibly old model carbureted engines, which are considerably cheaper initially and possibly overall.
If the engine won’t crank, you first need to verify if it’s turning over. If the engine won’t even spin, then verify that the battery cables are tight and clean. If they are not clean, use baking soda and a wire brush to clean the posts off. If the cables are good, confirm that the battery is holding a charge. You can have this checked at an auto store unless you have a load tester. Volt meters can mislead you by showing a 12+ volt reading, until the key is turned. Replace the battery if it will not hold a charge. If the battery holds a charge but still dies after starting and stopping a few times, then the alternator could be at fault. A quick test for most alternators is to take a screwdriver and carefully touch the back center of the alternator. If you touch this shaft when the car is running, it will be magnetic and the screwdriver should stick to it very well.
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Recoil rope broke on your small engine? Here is a guide to repairing a lawnmower, chainsaw, outboard motor, snowmobile or weed eater recoil. The pull start assembly is usually easy to get to and will not take long to repair. Generally there are up to four screws that will need to be removed for the recoil assembly to come off. Once the housing is off you will see that the rope knot is probably still tied inside the inner housing. To make things easy try to pull the string through the hole of the recoil where it previously or still passes through. pull the rope and count how many times it turns. If you were lucky, that may be how many rotations you will need and won’t have to wind the new rope more turns. When the rope is tight see if you can stick a screwdriver all the way through the recoil slots so it won’t unwind. Slowly release the rope and make sure it won’t unwind. Carefully untie the recoil rope knot located close to center of the recoil and inline with the hole the rope passes through. When replacing the rope only use a rope made for recoils. A new general purpose recoil rope is literally only a few dollars.
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Small engine timing is completely mechanical. The coil is mounted closely to the flywheel. The flywheel is the large circle with cooling fins. The flywheel is on the opposite side of the engine from the output shaft. The flywheel has magnets mounted in it. As the flywheel magnets pass the coil they induce a current. The coil then discharges to the spark plug. The relationship of where the coil sits and where the flywheel magnets are, dictates the timing. The coil can be moved slightly to change the timing. Move the coil in the direction the flywheel moves and the timing will be retarded and opposite to advance timing. The only other factor that affects the timing is the flywheel. Occasionally the flywheel can shear it’s key on the crankshaft. The key locates the flywheel in the correct rotational spot to insure correct timing. If the key is sheared the timing can be anywhere, and the engine may spark but not run. The key is square and can be viewed from the end of the shaft. The key will have a cutout in the shaft and the flywheel. Offset keys purposely rotate the flywheel to advance timing.
It is relatively easy to convert a small gasoline engine to propane or natural gas. There are lpg/propane kits designed to make this conversion easy. They generally consist of a simple plate that sits between the carb and the engine. A regulator is usually attached to regulate the propane going to the spacer plate. The regulator is needed to supply more fuel as the load or power demand increases. Instead of the engine bogging down, the regulator supplies more fuel so the engine makes more power. Propane or lpg is already in a gaseous form, which does not have to vaporize and will not leave carbon deposits. Carbon is bad because it is hard and leaves deposits which cause engine wear. Carbon makes your oil black and breaks the oil down faster. Producing less carbon should dramatically increase an engine’s life. Power and fuel consumption are very similar to using gasoline. The power will vary depending on what engine it is being used on. Mileage will be similar, but could be better than a stock carburetted engine. Propane tanks are usually safe and are very resistant to impact. The tanks will vent if the internal pressure gets too high, for safety. Many people like to convert generators to natural gas/ propane. They use the same source as their home’s fuel source for heat. When the power goes out, they have a limitless supply of fuel without having to refill a generator tank up with gas cans. Conversion kits can be reasonably priced and bought online.
Naturally aspirated engines are simply engines that are not assisted with a turbo or supercharger. Most people that want their car to go faster will chose this way. Large power increases in automotive engines are not hard to get. Four stroke performance can be greatly improved over the mild factory setup. Four stroke tuning can greatly improve the power over stock conditions. The factory tuning is very mild because they need to pass emissions tests from the factory. Many people buy aftermarket computer chips with modified performance maps. This can improve many cars by 5 to 20 horsepower dependant on the vehicle. Aftermarket chips are also an easy install and can be purchased reasonably. As with all engines, moving air into the engine is the way to make power. Another easy bolt on performance modification is to install a high flowing air filter. Large gains can also be made with improved flow through aftermarket carbs or larger diameter throttle bodies. The import tuners usually purchase high performance intake tubes which try to draw in cool air. These kits usually give moderate performance gains. Most of the domestic car tuners do the same and tend to spend money on the actual intake manifold instead. Depending on the vehicle it came off the performance gains can be much larger some up to 40 horsepower on V-8 models.
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