I had this issue happen a few times this month.
​​​​​​
first time 2 times I had to tighten the battery connections.
​​​​​​
the third time the bike backfired shut off and all I had to do was pop it into N and start in back up.

I retighten the connections and took it for a ride. No issues.

I took it out 4 days later and when I was riding the bike and the bike backfired. I turned around hoping it wouldn't die on me again.

It's starts a little hard, but nothing it hasn't done before. The plugs look..ok..I replaced like 6k ago.

Any ideas?

Thanks.

 

When mine did that (backfiring) it was always the negative coming loose on the battery. I finally put some lock-tight on and it fixed the issue.

 

Have you had any issues taking the battery off the bike after you put lock tight?

 

No, just use a drop of the blue lock tight.

 

Are you using a factory OEM battery or aftermarket? Sometimes the aftermarket battery has an extra brass piece you need to put in that some unknowingly throw away.

Dave

 

Factory battery. I installed lock washers and it ran ok. I'll post a pic of my battery terminal. I think I found the culprit.

 

If not loose battery terminal connection maybe the TPS?

 

This was my issue. Running fine, then all hell broke loose. Bucking, kicking, sputtering, backfiring, then no power. Turns out the dealer had installed a Battery Tender harness...loosely and both terminals had loosened so much that they were arcing. It burned through the negative ring terminal on the harness but luckily didn't damage the new Harley sealed battery.

I pulled, checked, cleaned and fully deep charged the battery, installed a new harness with both blue LocTite 242 on the bolts as well as installed exterior toothed lock washers (the kind that can bite into the lead terminals around their entire circumference) and secured them with a box wrench, not screwdriver. I cleared all the codes that got thrown at the PCM, ECM, etc. and all is right with the Dyna-world once again.

Invest in a bottle of LocTite 242 (blue) and 271 (red). Most things on a Harley REQUIRE a little 242. Very few require 271 so be careful as it generally takes applied and focused heat to help loosen 271.

 

I think this was my issue. I had a battery tender harness on my battery and it was put on loosely and fried the terminals on my battery where the bolt threads in.

Plan is to buy a New battery. I installed lock washers for now it seems to work but idk for how long.

 

I’ve had the dreaded loose battery terminal experience too. It was with a Batteries Plus battery that needs the inserts. The Harley batteries hold better but I still use blue locktite on the battery screws too after that experience.