Bike-Tinker Posted Tuesday at 05:39 AM Report Share Posted Tuesday at 05:39 AM Frustrated .... '74 Yamaha TY250 Trials ran fine but a little flat at top end. Decided to try a CDI kit to get better performance. Installed the CDI kit and wouldn't start. I rechecked and set the timing with a strobe lite and turned the crank using a drill with socket in the CCW direction. Prior to timing, checked and marked TDC and .122" piston BTDC location on crank case. Next I pulled the spark plug. With the plug grounded to case i see a nice blue arc when i use the kick starter. After kicking my leg tired. Pulled the plug and it was wet. I pulled the plug and let the cylinder air out overnight and tried the next morning. No start. the kill switch in not part of the wiring at this point. So that is not shorting the coil to ground, ie have a spark. Since the bike ran before, I didn't think any thing like fuel quality or flow were an issue. But now having to go down that road to pull Carb and flush it clean and with fresh fuel. Do you guys see anything I might be missing. Been at this now for a week and no starting.....frustrated Quote Link to comment Share on other sites More sharing options...
konrad Posted Tuesday at 01:01 PM Report Share Posted Tuesday at 01:01 PM Seems like you have done everything correctly. Since you made the timing mark, are you sure it is BTDC and not ATDC? As a general comment, digital CDIs need their pickup location well in advance of the firing point to allow time for computation. It takes significantly higher voltage to fire the plug under compression than in open air. Try reducing the plug gap to half what it is now. I would not use the bike that way, just as a diagnostic test. If still no success, I would refit the OE ignition to verify the bike runs. Quote Link to comment Share on other sites More sharing options...
konrad Posted Tuesday at 01:17 PM Report Share Posted Tuesday at 01:17 PM Can you post a link to the Malaysia OHT bikes CDI? I can't find it with a search. Quote Link to comment Share on other sites More sharing options...
konrad Posted yesterday at 12:11 PM Report Share Posted yesterday at 12:11 PM I found this: https://www.ohtokc.com/products/electronic-ignition-yamaha-ty250-hit Did not see any written installation instructions on that website. Quote Link to comment Share on other sites More sharing options...
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