Recently, I've noticed a very hard engagement on my primary clutch. I measured the free length on the spring (GP green), and it was about 3/8 inch shorter than it should be. I contacted Goodwin, and they sent me a new spring free of charge. Unfortunately, it didn't seem to change the engagement.It's still very jerky at low speeds...engages at 4500, as it should, but disengages at about 4200 or so. I clean the clutches about every 300 miles. Anyone have any experience like this? Any advice? Thanks in advance.