This topic contains 5 replies, has 4 voices, and was last updated by Swamp 8 months ago.
June 20, 2018 at 8:51 pm #14662
TECH INQUIRY – 2009 BMW K1300 GT Sluggish cranking to start.
Bought in October 2017 with 7,000 miles. Now 12,900 miles.
The condition is “intermittent.”
The bike turns-over and starts normally 98% of the time. Cranks normally 100% of the time on first start of the day and when it is cold. The bike cranked and started okay after sitting more than a month with no battery tender.
One time in cold weather and after running the heated seat and heated grips I stopped for gas and when I went to leave the bike would not crank at all. Click – dead … not turning-over. Zero. I did not have a jumper wire or tools to open the battery cover. Push starting did not seem to work at all. I sat down for 20 minutes deciding whether or not to tow it. Just for the heck of it I tried the starter again and with only minor hesitation it light right up. I figured the amps drawn by the heat accessories outran the alternator and drained the battery.
When the engine is hot, and after frequent stops and starts, the bike cranks slowly for a second and then cranks faster and starts. Sometimes (under hot operation) the bike will barely crank the first time that I hit the starter and then 3 seconds later it will crank at high speed when I hit the button.
I do not know how old this battery is.
This reminds me of 1966 and 1967 Corvettes with the 427 Big Block engine and headers. The starter motor would get hot and warp or deform so much that it changed the gap between the magnets and the brushes. The cars would not start “hot” unless you jumped them for more cranking amps. The “fix” was asbestos insulation and aluminum heat shielding between the starter and exhaust.
This bike has all O.E.M. parts on it.
Any ideas ? Thanks.June 20, 2018 at 9:57 pm #14672
I’d replace the battery. It may need it regardless.
After that, starter switch, or starter.June 21, 2018 at 6:46 am #14673
After reading your post, I’d start with the battery as Mike suggested, and then go from there. Take your battery in and have it tested as well.June 21, 2018 at 8:08 am #14674
The new battery idea would sure be a great place to start, especially if your existing battery is more than a few years old. If you don’t want to spend the $$$$ on a new battery then at least have the battery load tested.
With hot cranking problems the obvious place to start the troubleshooting is to do a hot engine voltage drop test on the starter 12v supply cable from battery positive post to starter solenoid 12v supply stud, and on the starter ground side from starter housing back to battery negative post. Put voltmeter on low scale, like 10-20 VDC then put one meter lead on battery positive post and other lead on starter solenoid large cable stud to parallel the battery cable from battery positive post to starter solenoid large battery cable stud then hit starter button. Then place voltmeter leads between battery negative post & clean metal on starter body the hit starter button. The lower the voltage drop the better with anything under .25v great, anything under .5v OK and anything over .5v showing a possible problem, and anything over a volt being something that positively needs addressing.
If a high voltage drop is found then you have excessive resistance in that part of the starter circuit.
Otherwise a trip into the starter might be required to see if you have a hot starter armature drag issue due to worn bushings or something like a debris shield is loose inside the starter.
Hot engine starting issues can be somewhat difficult to diagnose easily as a tight piston or internal engine drag can act the same as a tight starter or low starter current.June 21, 2018 at 10:32 pm #14683
Thank you for the input. I will report if and when solid conclusions materialize.
There is some K1300 group discussion of a starter wiring harness recall and a design defect involving battery/starter wiring that is of insufficient gauge.
Thanks again.June 22, 2018 at 5:28 am #14685
Good luck, and report back after you find your problem.
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