81 CB 750C

Lots of frustration today, finished hooking up all the electrical after a few issues. Hooked up fuel and she started dumping gas on the floor. I realized I left one of the carb drains open when I cleaned them. Once that was sorted out I tried to start her with no luck. Verified all my connections still not working. She turns over but no start. Checked the plugs, they were wet but fouled and no spark. Guess I'll get new plugs and try again tomorrow.

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So currently the plugs and crankcase gasket are on order. I'm looking for some electrical help. Where should I be looking to solve the spark issue. I will replace the plugs but the fact that they don't have much run time on them and are just bit dirty lead me to believe they are not the issue. I just rewired the bike so I'm assuming I made a mistake somewhere. I double checked my connections so nothing is loose. The ignition coils are new (not that they're definitely not bad but I'm assuming they're good) ignition wires are all new. She turns over and everything seems to function properly but I can't get a spark. Where should I start troubleshooting and how? Can I test the spark units, coils, starter solenoid? Not sure what would cause a no spark issue.

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Did you upgrade to cbr coils? There is a relay mod you can do to improve spark as well. Check your ignition advance is right as well.
 
I did get cbr coils and I'm running a motogadget m-unit. I know about the relay mod, is it necessary with the munit? I'm getting everything to turn over and seems to be working correctly just no spark. I'm thinking I wired the ignition switch wrong.

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There are 3 wires coming off the handlebars I'm trying to figure out where they go. A black/red I have hooked up to the aux output of the munit. A blue/white going to the headlight lowbeam (I think this one is right). And a black that comes from the kill/start switch (my biggest headache) not sure where this should go. With it disconnected the bike turns over and everything seems to function properly but no spark. I thought it went to the aux output but nothing works when it's connected there. I also tried connecting it to the black/white wires for the coils and still no luck. Please help! I'm dying to get this thing running.

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Check that your timing is correct. If the timing seems right then you may want to check your ignition advance unit. If it’s not correct you’ll get no spark. You’ll have to remove it and inspect. They have an alignment stud that keeps it in line on the crankshaft. If the advance unit alignment stud is snapped off it won’t start. Mine had a broken alignment stud and wouldn’t crank. I can’t comment on the m-unit. I don’t really know much about it but I would start at the advance. If you’re not getting spark it’s probably there.
 
Replaced the plugs, reverified my connections and traced out every wire, checked my connections on the coils, plugs etc. then pushed the start button and... she fired up. I'm so excited right now! I'll hopefully get her on the road in a week or two, just in time for the cold weather to roll in

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All done with my clear coat on the tank and tail section. Final assembly will take place this week and carb sync asap to get her reliably road worthy!

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Took Monica on her maiden voyage, she rode great! Carbs definitely need synced up she was sputtering on deceleration and idle was a bit high but I'm so excited and relieved to have her on the road! Thank you everyone that's helped me out, I wouldn't have her on the road without all the info and knowledge from you all.

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