Posted November 19, 200915 yr I have recently acquired a 1973 Yamaha MX175, I have no spark, I don't know much about the electrical systems on dirt bikes..What is the best way to troubleshoot the system? and if needed where would be a good place to get cheap replacement components like the magneto and CDI unit? Any help would be appreciated..Cheers!
November 24, 200915 yr I have recently acquired a 1973 Yamaha MX175, I have no spark, I don't know much about the electrical systems on dirt bikes..What is the best way to troubleshoot the system? and if needed where would be a good place to get cheap replacement components like the magneto and CDI unit? Any help would be appreciated..Cheers! No such thing as cheap! i may be able to help with the cdi box. I build them for some of the big single 4 stroke yamahas, there's not much difference to the 2 stroke machines in terms of cdi ignition systems.
November 25, 200915 yr Author What's involved in rebuilding the cdi box? Is it something I could do with some direction or is it complex and would be better off getting a replacement?
November 25, 200915 yr Moderator I have recently acquired a 1973 Yamaha MX175, I have no spark, I don't know much about the electrical systems on dirt bikes..What is the best way to troubleshoot the system? and if needed where would be a good place to get cheap replacement components like the magneto and CDI unit? Any help would be appreciated..Cheers! its no use going to the most expensive part if you havent got a spark...you must do that one last and check everything else first, there will be various coils to check...a kill switch?...dunno get a wiring diagram first
November 25, 200915 yr its no use going to the most expensive part if you havent got a spark...you must do that one last and check everything else first, there will be various coils to check...a kill switch?...dunno get a wiring diagram first true, its often a simpler fault; spark plug, wiring or a generator coil, i was assuming these had been tested? But i can test the cdi box if needed as i have a specialised test rig that will run the box off bike. Generally they can't be repaired, unless you can open the case and see the circuit inside. Most of that type of cdi was sealed with epoxy compound meaning you can't get at the circuit board.
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