i have a 1982 yamaha550 vison it will not start i have spark but it will not fire i cleand out the carbs hellp

Answer 1

Check your carb boots very carefully.
They can, and will, develop cracks and leaks that cannot be seen by the naked eye.

Those gas tanks are notorious for collecting water in the low points and rotting out. Your petcock screen may be clogged.

The starter roller clutch may not be engaging properly. If the engine does not spin fast enough, it will not start.

Repeated attempts to start before fixing the problem will cause the starter brushes to wear badly.

Answer 2

The other two guys are right except they left out another key ingredient to start a bike. Oxygen. If your carb is working right and you have spark, then it might be an air problem. Change your filter and make sure the air passage isn't clogged. Use a multimeter to make sure your coil is outputting the right numbers. Also, is your starter motor working properly or is it kick start? I would check all of these things.

Answer 3

It sounds like you know a little bit about what it takes to get a engine started,you need fuel and spark and compression.Make sure you have good clean fuel and it is flowing out of the tank good.If there is any chance that you have moisture in the tank take it off and clean it out,most tanks rust out badly and cause fuel problems.Take out the plugs and squirt some 10w30 oil into the cylinders then turn over the engine a few times install the plugs and see if it starts.Hope this helps good luck to you my friend.

Answer 4

If you have fuel and spark, it should at least fire. Check your timing and double check your carbs to make sure EVERY passage is clean. The small pilot jets on your bike are easily clogged and would cause the symptoms you're describing. To unclog a pilot jet, I find using a small firm wire is the perfect tool to pass through the jet without damaging it. I would even throw new sparks in it just to make sure that they aren't fouled.