WILL NOT IDLE

[Tim M]

I recently replaced my stock carb with a new carb and velocity stack/air cleaner. And i can easily start the engine and get it to run just fine but when I come to a complete stop or let off of the throttle completely the engine dies. I can easily get it to restart by just popping the clutch and giving it throttle again but every time i let off the throttle all the way it dies. Can someone give me an idea of what is going on.

 

[IAmASchwinner]

According to your description of your engine's behaviour, it sounds like a problem with the new carb (obviously). This has happened to me several times, and each time it's due to the amount of fuel and air that goes into the engine at a resting rate. There are two possible conditions. You could be running rich, or running lean. The fuel to air ratio refers to the correct amount of fuel per air parts to run perfectly. Each engine may have a unique fuel to air ratio, and you have to find it yourself.

If you are running rich, this means you may be allowing too much fuel to run through the engine, which requires more air, or you are allowing the right amount of fuel but not enough air. On the other hand, if you are running lean, this means you may not be allowing enough fuel to run through the engine with the right amount of air, or too much air to begin with.

I would recommend adjusting the amount of air or fuel (one at a time) that goes through the carb, and observing the results to reach the proper fuel to air ratio. Honestly, just play around with it until it idles with the desired power. Good luck, hopefully I could help.

 

[Frankenstein]

There's a little screw used to adjust the idle. Turn to the right to increase the idle speed.