Compression Valve

[chauke]

I recently bought a Yanmar 1500 tractor and have a question. Before I went to look at the tractor, I watched some Youtube videos to get familiar with some basic starting/operating a tractor. One of the videos showed someone using the compression valve when starting the tractor. When I went to check it out, the previous owner didn’t use a compression valve when he started soi I just assumed it didn’t have one. Later, I noticed the compression valve and asked about it. The previous owner didn’t even know it was there. It seeks like I should use this when I start it. However, I am concerned that if it has not been used for so long, would it be worse to try to use it now? My concern is that if it somehow failed when I was trying to use it and would be stuck in the “exhaust valve partially open position” that then I wouldn’t be able to even start it. Thoughts?