Slow Cranking 87
#1
Slow Cranking 87
Hi, I have been chasing a slow cranking issue in my 87 FLH for YEARS and have never gotten it sorted.
Issue: Hit the starter button and you get a very slow and strained crank (2 or 3 revolutions) like it has super high compression, which it doesn't, it is a new S&S 80, but not a hot motor. Heck it even did this with the old tired Harley block in there. After a few seconds of holding the starter button down, it speeds up a tad, but sometimes, it does not crank fast enough to start and the battery will loose sufficient power to throw it over all together. Sometimes when this happens the starter won't disengage at all. Once started, I can ride all day, but it will still exhibit this behavior on every start up, even hot and with fully charged battery.
This is with:
New All ***** 1.4KW starter
battery cables #4 gauge with clean connections including grounds
AGM 300CCA Battery new and freshly charged
Newish solenoid
Newish Starter Relay
I have applied an extra ground and an extra power cable from battery to starter using jumper cables and that did not help.
Someone has to have experienced this issue before...
I know it sounds weird, but could it be the Bendix?
Issue: Hit the starter button and you get a very slow and strained crank (2 or 3 revolutions) like it has super high compression, which it doesn't, it is a new S&S 80, but not a hot motor. Heck it even did this with the old tired Harley block in there. After a few seconds of holding the starter button down, it speeds up a tad, but sometimes, it does not crank fast enough to start and the battery will loose sufficient power to throw it over all together. Sometimes when this happens the starter won't disengage at all. Once started, I can ride all day, but it will still exhibit this behavior on every start up, even hot and with fully charged battery.
This is with:
New All ***** 1.4KW starter
battery cables #4 gauge with clean connections including grounds
AGM 300CCA Battery new and freshly charged
Newish solenoid
Newish Starter Relay
I have applied an extra ground and an extra power cable from battery to starter using jumper cables and that did not help.
Someone has to have experienced this issue before...
I know it sounds weird, but could it be the Bendix?
#3
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Summers420us (10-30-2017)
#5
Mate there is a mod to bypass the coils so it turns over a few times before it lights up , that has helped quite a few guys over the years it's in my old PC though , it's not a hard wire up either.Gooogoool knows .
You've obviously replaced or fixed anything that might be holding you back does the starter get really hot ? That will show if it's not happy the starter staying on is a clue too, how's the center tank switches all good ?
Sometimes it's something you just haven't thought off.
Try shorting it to start at the solenoid man use a big *** screwdriver see if it turns freely that way.
You've obviously replaced or fixed anything that might be holding you back does the starter get really hot ? That will show if it's not happy the starter staying on is a clue too, how's the center tank switches all good ?
Sometimes it's something you just haven't thought off.
Try shorting it to start at the solenoid man use a big *** screwdriver see if it turns freely that way.
Last edited by badcooky; 10-28-2017 at 01:38 AM.
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Summers420us (10-30-2017)
#6
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Summers420us (10-30-2017)
#7
For the hell of it, do a compression test and post the results. It's cheap and it's quick.
Remember disconnect power to coil, remove both plugs and throttle open 100%, note first revolution compression and 8th revolution compression. Also how does it turn over with plugs out?
Let us know... Post it...
Remember disconnect power to coil, remove both plugs and throttle open 100%, note first revolution compression and 8th revolution compression. Also how does it turn over with plugs out?
Let us know... Post it...
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#8
Hey Tups, et.al:
Well, if I was gonna look at it, I would take my meter and check the voltage directly across the battery terminals when cranking. What is it? , Then alligator clip the negative lead to a good ground point near or on the starter or primary, take the positive lead and alligator that to the battery terminal on the starter, hit the starter button and see what the voltage is there. Is it the same as across the battery? If it is not real close, start going backwards from the starter and see where it drops.
I don't think the solenoid design on our bikes is all that great. The switch itself tends to get carbon buildup. Also, comments on the bearing in the primary above would be a good thing to explore if you can't find any electrical issue.
And my bike does it sometimes also. Especially when the battery is getting a bit weak. My bike is a battery killing machine. I go through about one a year. Two years is "Wow, that one lasted a long time."
Well, if I was gonna look at it, I would take my meter and check the voltage directly across the battery terminals when cranking. What is it? , Then alligator clip the negative lead to a good ground point near or on the starter or primary, take the positive lead and alligator that to the battery terminal on the starter, hit the starter button and see what the voltage is there. Is it the same as across the battery? If it is not real close, start going backwards from the starter and see where it drops.
I don't think the solenoid design on our bikes is all that great. The switch itself tends to get carbon buildup. Also, comments on the bearing in the primary above would be a good thing to explore if you can't find any electrical issue.
And my bike does it sometimes also. Especially when the battery is getting a bit weak. My bike is a battery killing machine. I go through about one a year. Two years is "Wow, that one lasted a long time."
Last edited by Dr.Hess; 10-28-2017 at 11:05 AM.
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grbrown (10-29-2017)
#9
Even though you have that great all ***** starter...it still uses the crappy factory gear reduction which is a poor design.
Spyke makes a starter for that bike with a different gear reduction that will spin that motor faster with less battery...but they are proud of it. (pricey)
Ultima makes a copy of the Spyke starter...I have had one for 6 years and have yet to kill it.
https://www.ebay.com/itm/Ultima-Chro....c100011.m1850
#10
Every hear of anyone changing the primary to a post 91 version so they can run the later starter set up?