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Discussion Starter · #1 ·
I bought my 95 VN750 last spring and it has been an excellent bike to learn on, Took a 1400 mile trek on it this summer but as I got into fall it started giving me some trouble.

I had no spark to the front cylinder and after screwing around I traced it to a broken wire between the pickup coils and my IC Ignitor, I spliced it together again and it runs great now, until it gets up to temp. Once the engine is hot it looses a ton of power, the tach bounces, and I get occasional backfires. It seems to start happening consistently when my temp gauge comes back down to operating temperature after the thermostat kicks in. I've cut the 45 into the line in the right ear, and have run it with the gas cap open to eliminate any air or POOGS issues and it still runs rough when up to temp.

Does this sound like its pickup coil related? Should I look into doing the pickup coil mod?
Did I screw up splicing those wires back together and have created a "hot open" situation?
Or am I running into another issue?

I appreciate this site greatly, it's helped me with a handful of other issues with the bike and I couldn't find a thread that seemed to have the same issue so if you guys could point me the right direction that'd be awesome!
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The tach runs off one of the coil feeds. (front maybe) So I would look at that coil, it's pickup coil, and connections.

It's not uncommon for a coil to stop working when hot, but still work when cold.

The ic ignitor or CDI box can also fail under heat.

You could use an inline spark checker to watch the spark while running, or just check for spark as soon as it dies. Carry any spare spark plug and hook it up.
 

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If it's a coil, replace both with high output coils and new plug wires. Big difference, really helps our bikes with starting issues. My son's VN sat for a few weeks so I took it out yesterday. Started right up, ran great.
 

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VN 750 1994 RED/BLACK/SILVER
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Cold okay, hot not okay, in combination with the other associated problems identified, does sound like an electrical fault somewhere! Probably coils or associated ignition fault. Are the igniter units reliable on these machines?
 

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Cold okay, hot not okay, in combination with the other associated problems identified, does sound like an electrical fault somewhere! Probably coils or associated ignition fault. Are the igniter units reliable on these machines?
The ignitor has a decent track record, but there have been failures reported here.

Best thing to do is the ohm testing on the ignition coils and IC Ignitor.
 

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Discussion Starter · #6 ·
Finally took a look at the pickup coils and one of the wires to the pickup coil that sits at about 8:00 was not attached! Simple fix! I stuck the wire back in it’s place and it runs flawlessly even when warm! I’ll just solder it in place so it doesn’t hop out again and it looks like I’m good to go. I’m stoked because there should be a couple good riding days here before the snow flies!
thanks for the advice everyone!
 
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