Hi. I have a 250 trx honda fourtrax 1987. I had last year swapped in a new engine which has ran perfect up till a month ago. I jumped on it and kick started it, started and immediately stopped no spark. I ended up taking front plastic off and checked all the connections cleaned up grounds etc. I did get spark back for a bit and started the bike which did not want to idle. I got a new plug and started it but again did not want to even rev up this time, and died, no spark. I have a complete parts bike, i swapped the entire wireing harness, checked all fuses, swapped out the nutreal sensor, swapped the complete stater and exciter coil, i have no key so its hotwired, and no battery but charging system is working fine. With the new harness all the box's, coil, and all the other stuff has been changed. I checked the run switch looks fine, and was told i could disable it by pulling the green wire, still nothing. Great compression, oil light comes on bright when i kick over. Cleaned every connection also, and i did end up putting a battery in it, but nothing. Its got me stumped, any ideas are welcome. Thanks