Ive had one of these in an old classic XL70 for quite a while now. I use it as a pit bike and run the guts out of it around the house and chasing my kids. I was skeptic at first but this thing has been awesome for more than 5 years now! Can't ask for anything more really? Most recently my maintenance was short, and the bike threw the chain and tore up the ignition. Not the bikes fault, but Tbolt has all the parts needed and at very fair prices. Im hooked on these for life. Once my youngest is ready we are gonna swap his XR 70 engine with one of these and I can't wait to see his eyes when he feels the power!