I've converted mine to short needle. Its just easier as i've been running nitro for 10 years and have always been used to having and tuning with a short needle. Just for future reference how long does the needle need to be and how do you properly grind it down. Also should you retaper the needle once shortened or just leave it blunt? I just basically copied my other needle that was shortened by a professional go engine tech, but would like to know the specs for future use. I plan on running go engines from here on out on both my buggy and truggy and even have a spare on hand just in case.