Jeds Posted November 19, 2009 Share Posted November 19, 2009 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! Link to comment Share on other sites More sharing options...
Speedshop Posted November 24, 2009 Share Posted November 24, 2009 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. Link to comment Share on other sites More sharing options...
Jeds Posted November 25, 2009 Author Share Posted November 25, 2009 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? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 25, 2009 Moderator Share Posted November 25, 2009 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 Link to comment Share on other sites More sharing options...
Speedshop Posted November 25, 2009 Share Posted November 25, 2009 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. Link to comment Share on other sites More sharing options...
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