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.
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.
The idle air control is a control system used on fuel injected cars. The idle air control or IAC valve controls the idle speed of the engine. The IAC valve is controlled by the ECM (computer). The computer gets it’s information from the rpm which is supplied by the distributor, crank or cam sensor. The IAC valve moves in and out to bleed air behind the throttle plate. This air bleeding is the same as opening the throttle plate. The idle speed can be controlled precisely the throttle plate which isn’t controlled as well. Air conditioning will drop the idle speed down and will kill the engine if the IAC doesn’t work well. The idle air control will be located on the side of the throttle body. The IAC can become sticky after time and will cause the the engine to surge, rev or stall the engine. The valve can be removed and cleaned if not too severely worn. Usually the valve needs to be replaced. Make sure the gasket looks alright. Also make sure the idle air control is secured well and doesn’t leak air, or the engine will rev up.
Go carts can be complex racing carts or simple back yard projects. Many of the racing carts have pre built chassis that are design specific for racing. Most people will purchase a cart for racing instead of building one. There are three popular type of racing carts oval dirt carts, briggs and stratton and tecumseh type carts for pavement racing and shifter type pavement carts for faster road courses. Homebuilt carts are not so critical and can be built from steel tubing or even wood depending on the chassis required. The engine is usually a small four stroke engine such as used on a garden tractors or lawn mowers. If this type of an engine is used the transmission of power is usually a centrifugal clutch running to a sprocket on the drive axel. This limits the cart to be a one speed. Another option is to use a two stroke engine from a snowmobile or an off road bike. The high power and multi gear ratios of both vehicles make them both very fast drivetrains to use. You will want to use a very good brake set-up for one of these drivetrains. A cheap used snowmobile has everything except the chassis all integrated together and gives the cart far more power than it needs. The snowmobile transmission is variable and is fully automatic as it doesn’t need to be shifted. Shifter carts use the engine and transmission from an off road motorcycle. This requires the driver to shift but is also very effective and fast.
A standard car’s distributor ignition coil can be tested by checking the ohms reading. Ohms can be read on a volt/ohms meter. Ohms is a unit of measure for the resistance that a wire or coil has. Ignition coils should be measured on the primary coil between batt and tach terminals. The batt is the coil ground. To check the secondary coil, check the ohms between the batt terminal and where the coil output wire plugs into. If the ohms read zero the coil connection is broken and the coil is no good. An open coil reading zero is the usual culprit of coils. Don’t test through the output wire though. The primary coil should read between .7 ohms and 1.7 ohms, if outside this range replace it. The secondary coil should generally read between 7.5K ohms and 10.5K ohms. If the ohms are not within the specified range for that paticular car, replace the coil. Coil resistance will also change and vary if the coil is hot or cold. This a generalized ohms range that fits most distributor coils. Another thing to remember is that sometimes a coil will only read bad after it gets hot. It may work intermittently after it gets hot also. Coil packs will generally read around .3 to 1.5 ohms on the primary side and 12.5K to 13.5K ohms on the secondary side. These figures will get you reasonably close to where the coil’s ohms need to be to work properly.
