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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: castaway12000 on September 10, 2017, 10:45:51 PM

Title: Engine turnover
Post by: castaway12000 on September 10, 2017, 10:45:51 PM
when I hit the starter button... the engine turns over like twice maybe three times and then stops till I repress the button


Is this normal? Or should it crank as long as I hold the button?
Title: Re: Engine turnover
Post by: Laitch on September 10, 2017, 11:06:19 PM
when I hit the starter button... the engine turns over like twice maybe three times and then stops till I repress the button
Is this normal?
No, it is not normal. What have you checked regarding this condition?
Title: Re: Engine turnover
Post by: castaway12000 on September 10, 2017, 11:39:10 PM
Nothing yet as the bike would always start or almost always start in the first crank. 


As long as I hold the green button the estarter and engine should turn?   



Title: Re: Engine turnover
Post by: castaway12000 on September 10, 2017, 11:41:29 PM
I did a semi load test by hooking up the volt meter while I start it.   The battery voltage drops to about 11 when the starter engages and returns to 12.6 when t stops
Title: Re: Engine turnover
Post by: castaway12000 on September 10, 2017, 11:52:02 PM
I guess I should restate.


If I hold the green button down... it will turn a couple times, then stop for a few seconds then do it again. 
Title: Re: Engine turnover
Post by: Laitch on September 10, 2017, 11:59:27 PM
Nothing yet as the bike would always start or almost always start in the first crank.
I did a semi load test by hooking up the volt meter while I start it.   The battery voltage drops to about 11 when the starter engages and returns to 12.6 when t stops
I guess I should restate.
If I hold the green button down... it will turn a couple times, then stop for a few seconds then do it again. 
 

The starter should keep rotating the crankshaft until the battery runs down, the starter relay is fused and you finally start checking starting components—like the condition of its ground connections, the tightness of its battery cables and its transmission ground cable and the positive connection of all its major electrical plugs—after recharging your battery—or purchasing a new one—then buying a new starter relay because the fused one didn't start working again after banging it with a screwdriver handle.
  :yes
Title: Re: Engine turnover
Post by: castaway12000 on September 11, 2017, 03:19:03 AM
Let me look into a starter relay.  Hahaah
Title: Re: Engine turnover
Post by: Inge K. on September 11, 2017, 03:55:23 AM
If the starter goes on-off-on-off-on-off while the green starter button is pushed in all the time,
it is the sign of a bad hall effect sensor.

If the problem was a fused starter relay the starter would run all the time, even without the key
in the ignition switch.
Title: Re: Engine turnover
Post by: Laitch on September 11, 2017, 05:37:46 AM
If the starter goes on-off-on-off-on-off while the green starter button is pushed in all the time,
it is the sign of a bad hall effect sensor.
Things are looking up, castaway. A bolt-in solution is on the horizon, maybe, if your description is accurate.
Title: Re: Engine turnover
Post by: CNRED on September 11, 2017, 08:23:56 AM
Had a simular issue with my 90 K75rt, pulled the starter and cleaned it, solved the problem.
Title: Re: Engine turnover
Post by: Andy FitzGibbon on September 12, 2017, 06:11:56 AM
I had a similar problem. My bike would sometimes do one crank, wait two seconds, do another, and so on, if the start button was held down. The cause seems to have been bad connections at both the clutch safety switch and the gear position indicator in the gauge cluster- the two circuits that supply power to the start button. In my case, both circuits had enough voltage drop (due to the bad connections) that they sometimes wouldn't supply enough power to hold the starter relay engaged, and it would open and close over and over.


Cleaning and lubricating the starter motor wouldn't hurt, either, along with checking and cleaning all of the ground connections.


Andy
Title: Re: Engine turnover
Post by: jay1622 on September 12, 2017, 03:13:51 PM
How about cleaning the switch (handlebar button) with deoxit or something of the like?
Title: Re: Engine turnover
Post by: Chaos on September 12, 2017, 04:33:08 PM
mine does that when the battery is about ready to give up
Title: Re: Engine turnover
Post by: Christopherguzzi on September 12, 2017, 08:38:04 PM
Interesting problem.  Once I tuned up my brick along with new fuel pump and battery I wouldn't know if it does this or not as it pops right off when I hit the starter button.  I did have some weird electrical flickering and clicking at one point, however, so I backed up the bike several feet while in gear (as suggested on this site) and it resolved the issue. It would seem that this is quick, albeit less than thorough way, to clean the starter brushes and commutator???   Sorry I'm not much more help.
 :dunno
Title: Re: Engine turnover
Post by: castaway12000 on September 18, 2017, 05:23:30 PM
Interesting you brig up hall sensor


So, now the bike won't start, and I found that no spark was being sent to 2 and 3 plug.  So I switched the input plug wires to the coils and the problem moved to 1 and 4.   This is indicating that the coils are ok and that the problem is with the signal being sent to the coil


Reading around and this is also a symptom of a bad Hall effects sensor?
Title: Re: Engine turnover
Post by: castaway12000 on September 19, 2017, 08:16:45 PM
Is it worth trying the ICU first?
Title: Re: Engine turnover
Post by: jay1622 on September 19, 2017, 09:09:16 PM
I know this random (and seemingly unrelated to the starter circuit), but how is the ground connection for the coils? Correct me if I'm mistaken, but the coils and harness are isolated from the block (intermediate housing in particular). Find the coil ground lead (#3 coil on a 75 Brick) and determine if a good ground exists between the coil bracket, that lead and the coils. When my boy and I inspected the electrical system and it's ground points, we discovered a great deal of corrosion at the main ground terminals under the tank, and (completely unrelated) between the coils and the coil bracket, which is where the coil ground is established after that small lead. Regarding the HES, how's the wiring harnesses under the tank for all of that and the other terminals? How are the wiring harnesses for the fuel and ignition computers? Lots of continuity points worth checking indeed.
Title: Re: Engine turnover
Post by: Laitch on September 20, 2017, 04:46:30 AM
Reading around and this is also a symptom of a bad Hall effects sensor?
Reply #7, this thread.
Title: Re: Engine turnover
Post by: castaway12000 on September 21, 2017, 12:18:20 PM
Thank you everyone!
I went ahead and ordered a new one.  Side note, I pinned out all the wires for shorts and found no problems.  The plugs are all clean with no corrosion.


Also, interesting to me, when I pulled HES plate off and left it hanging, I hit the start button and yep... engine cranks without interruption.  As soon as I put the HES back in, it returns to on-off on-off starter engagement.   


Seems to me that if one of the sensors was bad, it wouldn't matter if it was installed or hanging there the problem wouldn't change.   


The tube with the hole cut in it that's connected to the engine.... does it it need to be black?  Mine is a bit rust color.   I cleaned it but did it make a difference
Title: Re: Engine turnover
Post by: Laitch on September 22, 2017, 09:34:54 AM
Also, interesting to me, when I pulled HES plate off and left it hanging, I hit the start button and yep... engine cranks without interruption.  As soon as I put the HES back in, it returns to on-off on-off starter engagement.   
Seems to me that if one of the sensors was bad, it wouldn't matter if it was installed or hanging there the problem wouldn't change.   
Things aren't always what they seem, especially when understanding about how they work is limited. :giggles