My Jonsered 525 has a Walbro HDA carb. I can't get it to tune right, so I was thinking of rebuilding the carb. However, there are quite a few different Kxx-HDA rebuild kits for the HDA carbs. It is marked HDA on the side, and has a very small "3" stamped under the HDA. Under the 3, there is a very small "L4" stamped. Any ideas?