Strange electrical starting issue

[Guest]

My gs650 has been having some trouble when starting cold. All the maintenance is done, it has a brand new fully charged battery and I checked the electrical system with the stator papers and she passed the first test. Here's my issue, when it's been sitting (on a battery maintainer) and I try to start her up with the choke both on and off she won't fire. Just cranks. As soon as I throw it on a jump with a car she fires right up. Once she's warm
Or been running she usually starts up no problem. It's just that initial start. What do you think the issue could
Be?

[spyug]

I'd say low voltage at the coils. Its very common that due to resistance in the connectors in the harness and the way the starting circuit is run, voltage drops considerably from battery to the coils. I have this condition in my 550 where battery voltage is down 2volts+ at the coils.

The solution is to try and cleanup or replace all connectors from the fuse block out, including connectors in the headlight area and contacts in the start button, kill switch and maybe even the ignition switch (key). If that does not bring back close to battery voltage, you can do the "coil relay mod" which puts a relay in to feed full battery power directly to the coils.

In addition to low voltage/weak spark you might find your valves need adjusting as tight valves occur over time and make starting harder than it needs to be.

Good luck with it.
Spyug

[tom203]

Without the jumper battery and at cold start , put your multimeter on battery terminals and crank it- what is the cranking voltage?