Author Topic: Whizzing and Clunking on Start up  (Read 10756 times)

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BRADEY

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Reply #15 on: February 15, 2012, 12:33:28 pm
My bike has shown signs of just "ghrrrrrrrring" and not starting the engine this winter (without any clunking metalic sounds).

Even the initial sound of the motor trying to start the engine would die within few seconds of pressing the button, to a muted sound, that encouraged me not to press the starter button for too long. Even with kick it would take a few, before coming to life.  ;D

Does this mean battery problem or sprang problem........ It is a two year old bike.



jartist

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Reply #16 on: February 15, 2012, 04:46:06 pm
Seems like it would be easy enough to remove the little cover over the top of the starter gear cluster on the top left of the crankcase and look to see if the starter gears are spinning when you crank the starter. If they spin but the engine isn't cranking it would be the sprag.


Ducati Scotty

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Reply #17 on: February 15, 2012, 05:19:02 pm
If you don't spin fast enough sometimes the sprag doesn't engage or engages sporadically.   That's why a borderline battery can mimic a bad sprag.

Prof, do you still have the original battery?  How old is your battery?

Scott


prof_stack

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Reply #18 on: February 15, 2012, 07:29:21 pm
If you don't spin fast enough sometimes the sprag doesn't engage or engages sporadically.   That's why a borderline battery can mimic a bad sprag.

Prof, do you still have the original battery?  How old is your battery?

Scott
Yes, the battery is the original, about 18 months since bike purchase.  With the battery always at full charge before startup, the FIRST cranking should spin the motor fast enough to catch the sprag, if that is how it works.  BUT, perhaps a new battery is in order.  Before I spend $$ on that, I'll let the shop perform the stress test.  However, I believe they did that when I brought the bike in for this same issue. 
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prof_stack

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Reply #19 on: February 16, 2012, 12:30:04 am
Okay, the dealer said to bring it in.

So I went home and made a recording of what happens on startup for them to see.  

It started on the first try and acted quite perfect.  That's a good thing.  The filming seemed to be the magic solution. 

...edit...  All is good, so I will keep an eye on future starting glitches.  Hopefully there will be no more.
« Last Edit: February 16, 2012, 09:52:58 pm by prof_stack »
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jartist

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Reply #20 on: February 16, 2012, 01:03:16 am
So you solved the problem:  Just start filming when you need to start it! ;D


prof_stack

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Reply #21 on: February 16, 2012, 01:33:31 am
So you solved the problem:  Just start filming when you need to start it! ;D
;D :D ;) :) ::)

Yeah, but doing the starting and stopping to test it seems to quickly foul the NGK plug.  I had to ride about 1.5 miles before it ran smoothly again. 

Now all is good.  ... for now ? ...I have some ideas.
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Arizoni

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Reply #22 on: February 16, 2012, 01:47:49 am
I know you haven't been able to get a good video of what is actually happening but in the second (September) version it sounded to me like the engine fired weakly and then the sprag clutch went into an "over-run" mode while the starter motor was still running.
This happens because the crankshaft speed was faster than the clutch speed and although one might think the pawls should instantly reengage they sometimes don't until everything has stopped moving.

This isn't necessary a major problem as long as the pawls reengage after the motor has stopped (as they did).

 
Jim
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1999 Miata 10th Anniversary


GlennF

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Reply #23 on: February 16, 2012, 03:14:58 am
So you solved the problem:  Just start filming when you need to start it! ;D

That could be a plan.

The other thing to check is no cute girls are watching.

It is a well known fact that Royal Enfields suffer from performance anxiety and rarely start first time when a cute girl is watching.


BRADEY

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Reply #24 on: February 16, 2012, 05:33:02 am
my bike replicates prof_stack's September video's first crank.
and this happens several times before the bike fires.......and at other times
it simply starts at the first press of the starter.

I am confused and trying to find some answers here..............?? ??