Important

Before you try to start the bike, firstly ensure that the battery is fully charged as the lamps will blow with a faulty or flat battery

Fuel

The fisrt thing is to check is the Fuel system

First, make sure the petcock (the petrol tap) works by disconnecting the hose from the carburetor and sticking the hose in a container. Then turn the petcock to on and reserve. Check that the fuel runs freely. Close the pipe with a finger and check that the petcock does not leak. Check the article on how to refurbish a petcock if it does. If the fuel does not run freely them it may be that the petcock is clogged or the tank may be clogged. Remove the petcock and observe it the fuel drains from the tank. The tanks are normally rusted quite badly and I normally install an inline free flow fuel filter between the petcock and carburetor. You can purchase this at a lawnmower repair shop.

Electrical

If the carburetor does get adequate fuel, the next thing is to check the electrical system. Take off the bike's seat. It's held on by an odd wing nut under the front of the seat. Check out the wires under there. Make sure they are all connected tightly. Check if the battery is fully charged check the fuse in the little casing. If it is blown, replace it. Pull out the spark plug. Clean it off. Set the gap to about 0.65 MM. Now connect the plug to the plug cable, and rest the very end of the plug on the head of the engine. Kick the starter a few times and check for a nice blueish yellowish spark from the plug. If not you either have a bad cable, bad coil or bad points or the CDI in the case of the two speed model is faulty. It would be a good idea to put in a new plug if the one you have is worn or the wrong type. Try a NGK BPR4HS

Carburetor

Remove the air filter housing and pull all air, fuel and oil pipes from the carburetor. Remove the accelerator cable from the top of the carburetor by turning the top counterclockwise and pull out the accelerator. Remove the carburetor by removing the two small bolts that attach it to the inlet manifold. Use the Carburetor Cleaning section for details on cleaning.

Final Running Adjustments

Once the bike is running and warmed up, park it on the center stand (with the air box on) and slowly adjust the THROTTLE STOP SCREW (the upper one). Turn it out to slow down the idle. Turn it in to speed up the idle. If the bike dies as soon as or shortly after you release the throttle, then increase the idle. If the wheel turns more then very slowly when the bike idles, then lower the idle. Turn it in slow amounts and then rev up the engine for a few seconds, then let it drop back to an idle. If all goes well you now have a running bike.

You can also try adjusting the IDLE MIXTURE SCREW if your bike still won't idle well. Turning it in makes the idle mix richer (more fuel) which is better for cold starting and idling with the engine cold. Turning it in too much though will also cause problems. Turning it out will result in a leaner mix. This gives a better warm idle and can solve problems of choking when accelerating from a dead stop. I normally find that between 1.5 and 2 turns is the best to make the bike run well.