I’m starting a new thread as a follow on to this one from last week
After replacing my battery with a new one, my problem remains. When I crank the starter, it cranks very slowly, just like it would if the battery was running down. It will generally start but it isn’t confidence inspiring. My old Ducati ST2 had this problem and there was a well known problem underspec’d wiring, as explained in this quote
“Condition: Bike is difficult to start, starts slow or not at all, sometimes fouls plugs. Takes multiple attempts to get it started. Rider has low confidence of bike starting.
The Cause: Underspec wire size plus brass or steel terminals throughout the starter circuit have created chokepoints to the current flow. Starter motor receives less current than it requires which necessitates long cranking times. The excess cranking depletes battery voltage below that required by the ignition system to start the bike. Multiple cranking events eventually allow the chemical reaction in the battery to create enough current to start the bike but battery is damaged by long discharge cycles.
The Bandaid Install new or larger battery - bike starts well until excess resistance in starter circuit degrades new battery.
The Solution Install a HICAP high current starter circuit that has the least possible resistance to current flow
* HICAP - outboards and replaces the OEM starting circuit that is riddled with chokepoints that impede current flow.
* * Pays for itself in reduced battery consumption and reduced starting system wear.”
Does anyone think I could have a similar issue? If so, what would be the procedure to test this?
I have copied some of your original posts from the other thread, I realize the thread was derailed so lets try again. You have a new battery, please state what you have, is it the AGM Yuasa ?
So the next step is fun, one of two things, I very much doubt it is the starter, first place I would put my money is the engine ground, extremely difficult to get at on the MK-3, ABS is in the way, so is the frame, believe it or not, the easiest access is doing a valve shim check with the throttle bodies removed ( don't think you want to do that. Access is from the clutch actuator side of the bike, with the plastic removed.
You really need to remove the bolt and clean away any oxide, as the starter uses the aluminum casting for the negative power, on my 07 I found heavy aluminum oxide under this connection, which happens to be the negative wire from the battery to engine aluminum ground connection.
Another simple test would be to connect a voltmeter across the starter solenoid , it will read battery voltage with the meter across the solenoid contacts, observe the voltage while the starter is engaged, it should read around 0.2 to 0.5 VDC, if you read above 1 volt your relay ( solenoid) is shot. This last test would be the simplest. Also I mentioned previously about checking engine grounds and frame grounds, on the MK-3 they are numerous, I recall something like 9 frame grounds.