it will start without it. lots of people disconnect them or plug the hole where the valve goes because they can leak. i never use the one on my hobbit or 103. it might take a little more effort to start. It just makes it easier to get momentum because it reduces engine compression. but make sure its not loose or leaky. if you dont understand compression you can find some good info in the wiki. a well tuned pa50 will still start easy without the valve hooked up. working lights are a good sign but it doesnt mean you have spark. check the wiki for how to check for spark.