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Author Topic: Sudden on/off loss of power? Help please  (Read 1661 times)

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Offline justinmcgiver

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Sudden on/off loss of power? Help please
« on: May 21, 2008, 04:55:31 PM »
"74 750, Dyna S ignition, Dyna coils and wires freshly installed. Quite sure this is not a fuel problem as my carbs are clean and my jetting is spot on. She's been running perfectly. Went for a "spirited" ride the other day. Was running great when I put her away. Next AM fire it up go around the block...at low rpm's when I pull up to a stop it starts to bog down and totally loose power. as I give it gas and start to pull away the power suddenly turns back on like a switch was flipped. This seems like some type of electrical problem to me. What do you guys think? Where should I start to hunt for the problem?
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'74 CB750 K4 - Lake Placid, New York USA

Offline scunny

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Re: Sudden on/off loss of power? Help please
« Reply #1 on: May 21, 2008, 05:00:10 PM »
start at your battery connections and main fuse
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Offline justinmcgiver

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Re: Sudden on/off loss of power? Help please
« Reply #2 on: May 21, 2008, 05:07:39 PM »
Yep, did that...They're good...
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Offline Shenanigans

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Re: Sudden on/off loss of power? Help please
« Reply #3 on: May 21, 2008, 05:10:03 PM »
Maybe check the kill switch to make sure its not cutting your power.
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Offline BobbyR

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Re: Sudden on/off loss of power? Help please
« Reply #4 on: May 21, 2008, 05:11:54 PM »
I would take a look at the wire running from the Dyna to the coils. I had a situation much like you describe, two cylinders were going in an out giving me no power then full power. Worth a look, they can get chafed. 
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Offline TwoTired

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Re: Sudden on/off loss of power? Help please
« Reply #5 on: May 21, 2008, 05:12:30 PM »
You using the electric starter, or Kick?

What is your battery voltage?

Got a Hi watt headlight, too?

Would those be 3 ohm coils?
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Offline justinmcgiver

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Re: Sudden on/off loss of power? Help please
« Reply #6 on: May 21, 2008, 05:21:53 PM »
Using mostly electric start when cold...kick when warm.

Darn, been meaning to get a multimeter...

Just installed a headlight kit with an H4 60/55...
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'74 CB750 K4 - Lake Placid, New York USA

Offline justinmcgiver

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Re: Sudden on/off loss of power? Help please
« Reply #7 on: May 21, 2008, 05:22:50 PM »
oh yeah...3ohm coils too.
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'74 CB750 K4 - Lake Placid, New York USA

Offline TwoTired

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Re: Sudden on/off loss of power? Help please
« Reply #8 on: May 21, 2008, 05:49:16 PM »
If you can't check your battery voltage, how does it run after it's been on the battery tender overnight?
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Lloyd... (SOHC4 #11 Original Mail List)
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Offline eurban

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Re: Sudden on/off loss of power? Help please
« Reply #9 on: May 21, 2008, 06:37:13 PM »
Make sure the mounting screws for the Dyna plate are tight.  The Dyna ignition gets a ground from the contact between the back of the plate and the crankcase.  The previous owner of my bike sold the bike (to me) because of an intermittent power loss / death of bike problem that ended up being loose plate mounting screws . . .
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Offline justinmcgiver

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Re: Sudden on/off loss of power? Help please
« Reply #10 on: May 21, 2008, 07:20:33 PM »
Ok...I'll put all this to the test tomorrow. For the record the battery is brand new. I'll try to get ahold of a multimeter tomorrow. Thanks for the help. see you tomorrow!
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'74 CB750 K4 - Lake Placid, New York USA
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