Damianharris Posted May 5, 2021 Share Posted May 5, 2021 Hi guys my bike is only firing on 2 cylinders. I have tested the coils and one was bad and I have replaced the pair but it still isn’t producing spark. I have tested the wiring and it has the live like it should have but still no spark. I’m thinking the coil isn’t getting any pulse from the cdi telling it to fire. Any ideas if it could be anything else? I have checked the battery and that’s fine. Thanks for any help. Quote Link to comment
TonyGee Posted May 5, 2021 Share Posted May 5, 2021 check continuity on the wire from the coil to the CDI first before you start replacing parts. Quote Link to comment
Damianharris Posted May 5, 2021 Author Share Posted May 5, 2021 I have already done that . The wiring is fine. Quote Link to comment
TonyGee Posted May 5, 2021 Share Posted May 5, 2021 do you know anyone you can borrow a CDI off ? Quote Link to comment
Damianharris Posted May 5, 2021 Author Share Posted May 5, 2021 No I’ve managed to get a second hand one cheap so hopefully once I fit it and the new coils that will sort it . I will test for spark before I bolt everything back together . Quote Link to comment
Upshotknothole Posted May 6, 2021 Share Posted May 6, 2021 Had this happen with a teakettle 750, if the lead that goes to the tach is grounding out, the coil that it’s hooked to won’t fire. Everything will test fine, but you’re not gonna get spark. Also try grabbing one of the old coils and a plug and check both leads to the coils with that. Easier than trying to plug and unplug the coils when they’re bolted to the frame. 1 Quote Link to comment
Damianharris Posted May 6, 2021 Author Share Posted May 6, 2021 18 minutes ago, Upshotknothole said: Had this happen with a teakettle 750, if the lead that goes to the tach is grounding out, the coil that it’s hooked to won’t fire. Everything will test fine, but you’re not gonna get spark. Also try grabbing one of the old coils and a plug and check both leads to the coils with that. Easier than trying to plug and unplug the coils when they’re bolted to the frame. The coils are already unbolted and off the bike. Only one of the coils don’t work. I wired the good coil into the bad side and didn’t get any spark. I run a multimeter from each end of the wire and the wire is good. Quote Link to comment
Upshotknothole Posted May 6, 2021 Share Posted May 6, 2021 Check the wiring diagram and see if it’s the coil that has a wire running from the coil to the tach. If so, check that wire. Went through a second set of coils and buying another CDI before finding that wire grounding out in the connector to an aftermarket gauge. Everything tested fine, annoying as hell. Quote Link to comment
Damianharris Posted May 6, 2021 Author Share Posted May 6, 2021 I’ve done that. I’ve just checked the pick up again. The manual says it should read between 135-200 ohms . Mine is reading 164 so that’s ok. Quote Link to comment
vizman Posted May 6, 2021 Share Posted May 6, 2021 If your coil went down, the plugs are probably fluffed on those two cylinders, have you tried cleaning/replacing them? Quote Link to comment
Damianharris Posted May 6, 2021 Author Share Posted May 6, 2021 18 minutes ago, vizman said: If your coil went down, the plugs are probably fluffed on those two cylinders, have you tried cleaning/replacing them? Yes I did that. Quote Link to comment
wraith Posted May 6, 2021 Share Posted May 6, 2021 Get a side light bulb and holder wire it to the coil leads -/+ (with out the coil on) turn the engine over, as if you're starting it, if the bulb lights up the CDI and wires to the coil are good. 1 Quote Link to comment
Buzuki Posted May 6, 2021 Share Posted May 6, 2021 When one of your ignition coil broke down that usually causes that one of the darlington switching power transistor inside of the CDI (ignition box) also is pull down , replacing that bad transistor (2SD1071) altogether with bad ignition coil usually is enough to successfully solve the problem . Quote Link to comment
Damianharris Posted May 6, 2021 Author Share Posted May 6, 2021 All fixed now thanks for the help guys Quote Link to comment
Wagola Posted May 6, 2021 Share Posted May 6, 2021 6 hours ago, wraith said: Get a side light bulb and holder wire it to the coil leads -/+ (with out the coil on) turn the engine over, as if you're starting it, if the bulb lights up the CDI and wires to the coil are good. Hi @wraith, never seen this done before. Will the bulb be on constantly or will it flash on/off ? Quote Link to comment
wraith Posted May 6, 2021 Share Posted May 6, 2021 5 minutes ago, Wagola said: Hi @wraith, never seen this done before. Will the bulb be on constantly or will it flash on/off ? Flash on/off very quickly Quote Link to comment
TonyGee Posted May 6, 2021 Share Posted May 6, 2021 11 minutes ago, Damianharris said: All fixed now thanks for the help guys well what was it ? 4 Quote Link to comment
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