Electrical issue, need diagnosis input please
 

OK, so not much happens fast in my world of motorcycles. My original 954 started having some issues last summer (still needs a new chain, to be addressed soon) and the most significant of these was that the bike would run normally for several minutes (ie: 30ish) and then start hesitating.

Eventually, after several good hesitations, which are extraordinarily dangerous depending on what you're doing, since you lose all throttle control, the bike would die and would not re-fire. This happened consistently, and I had to tow it home with the help of a good friend.

Since that time I've had it sitting in the garage mostly, and hooked to a battery tender. I bought a nicer 954 which runs just fine, so my attention shifted away from the 'sick' bike. Now I'm at the point where I want to repair the 'sick' bike and sell it to a new home in decent and safe condition.

Upon testing the two side by side (warming up) in my garage, what I found was that my gray bike will start normally and run, nearly complete its warm up cycle, and then ultimately die...fully replicating what happens out on the road. I had long suspected that there was an electrical component to this behavior, but feared there was more to it than that. Now, after some informal tests yesterday, I think it's all electrical.

Basically, when I left the bike hooked to its trickle charger and let it run and warm up, it never died. I could see the trickle charger blinking and feeding the battery while it ran, but this was enough extra juice to keep it running steadily all the way to full operating temperature. I watched the fans turn on and off a few times too. Without the trickle charger hooked up, the bike would only make it to about 177 degrees, and would then shut off and couldn't be re-started.

So, when I bought the bike I bought a new battery for it. The battery still seems to be good, so what other electrical components should I check that are leading to excessive consumption of electrical power?

I'm actually having the bike towed to a shop soon for a new chain and some front brake work, so it will be in the hands of professionals, but I'd love to get some input here to better prepare myself for parts that might need to be checked and replaced. Thanks all, and my apologies for the long and rambling read. :icon_boat:

It could be that you are running the battery down at idle. They don't charge at idle, so the tender is acting like a charging system.

Have you actually checked the voltage at the battery at 5k rpms to make sure it's charging?
Have the battery tested, or swap bike to bike, to rule a bad battery out.

Hey Demon,

Yes, very true...but something is running it down while it's riding and revving higher too. It will only run for a few minutes at idle whereas it will run considerably longer while being ridden...but still ultimately dies.

The battery *seems* to be OK, and definitely holds a charge well initially. However, that being said, you're right that I need to examine it as part of the entire system since it could be defective. Thanks for your input.

I'm at least semi-hopeful that someone will have experienced the same thing as me, and would say "oh yeah, same thing happened to my 954 and it was XYZ". That being said, I'm at the point where I'm going to have the bike serviced by professionals since I want it sold and I want it safe and enjoyable for the new owner too.

whats it charging at 5k rpms? get the bike running use a dvom volt meter . put the leads on the battery rev the bike up. also check all your connections powers grounds connectors all the basics .

R/R maybe???

Read up on these links, they give a pretty good over-view of the electrical/charging system...

Charging System Diagnostics - Rectifier/Regulator Upgrade - Triumph Forum: Triumph Rat Motorcycle Forums

https://cbrforum.com/forum/f2-tech-9...-solved-27739/

Technical Resources - Resources for Electrical Systems on Motorcycles and ATVs - ElectroSport

Hope this helps, Ern