Honda ATV Forum banner

87 fourtrax 70 no spark

18599 Views 7 Replies 6 Participants Last post by  TJeff
Picked up a fourtrax 70 for the kids yesterday. Needless to say they are more than anxious to get going but no spark. I cleaned up all the grounds and checked and cleaned connections. The grounds and kill switch seems to funtion ok. Key was eliminated wires are just connected together. How can I tell if there is power to the coil? What would be the first place to start on this problem cdi, stator, pulse generator? I pulled the side cover but didn't have a flywheel tool so thats still on there. It was suprising clean inside no rust. So are the aftermarket coils and CDIs for sale on EBAY junk or will they work.
1 - 3 of 8 Posts
Still no fire

Thanks for the help. I tried relocating ground. Checked continuity on all wires. Re-cleaned connections, checked coil it ohmed good and also tried coil from another machine. Some of the black wrap around the copper on one side of the stator looks like it may have got hot? Also, cleaned everythign up in side the LH side case. Still no fire. Is there an ohm test for the stator? I just tested across the ends of each side and had almost no resistance. How do you do it? I found something that said to check pulse generator by b/y wire and frame ground. I did that and it was @95 is that acceptable what i saw said it should be in the 200-300 range. I would think less is better right? Am I down to the cdi? I have a friend with a 87trx125 will the cdi work off that it has a different p/n that mine. Is that something to do with having a battery? Will it work just to see if I get spark before I drop $130 on a new one.
70 runs like a champ now. Bad coil and also the DA I bought it from had the wires for the key switch tied together. Honda key is off when grounded so didn't work so good like that. Pretty obvious once I had a wiring diagram.
1 - 3 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.