badhonda 0 Posted August 14, 2022 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 Share this post Link to post Share on other sites
toodeep 1,758 Posted August 15, 2022 On most of these older machines it's the CDI that gives the issue. I have an 89 350 that I tap on the CDI a couple times a year just waiting for it to die completely. What year is the parts donor machine? Are the parts known good from the donor machine? 1 Share this post Link to post Share on other sites
badhonda 0 Posted August 15, 2022 I am not sure on the donor bike year, but thinking its an 1986, mine is an 87. Cannot verify all the equipment ran on the donor bike. I bought it for the engine as my orginal, top end went to pieces. When orginally i had got spark back it was strong, but very quickly got weak and i had push the gas to keep it running, till it died. So something is weak and finally just stopped working. I read somewhere cdi is year specific? Share this post Link to post Share on other sites
badhonda 0 Posted August 16, 2022 I did check the donor bikes year, and it is a 1986. I ordered a cdi unit from amazon thinking the donor was a 1987. Will it work for mine? https://www.amazon.ca/gp/product/B07CZ7JWRR/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1 Share this post Link to post Share on other sites
jeepwm69 7,605 Posted August 16, 2022 Don't use Amazon parts. OEM only. The chinese crap never works and will have you chasing your tail. The CDI on the parts bike, if good, should work on your 87. If you look up a part on Partzilla, look in the bottom left corner and it will show you other models that the particular part is used on. https://www.partzilla.com/product/honda/30410-HA8-003?ref=3a68865b8b742dc081d9a891b96603ece6c643db 1 Share this post Link to post Share on other sites
toodeep 1,758 Posted August 19, 2022 Besides being Chinese junk that listing is for the sport model (250X). Share this post Link to post Share on other sites
