Author Topic: Slow crank.  (Read 10349 times)

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Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #25 on: May 07, 2015, 07:52:11 PM »
Still can jump sol and get great spark
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline calj737

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Re: Slow crank.
« Reply #26 on: May 07, 2015, 07:56:43 PM »
Look at a stock wiring diagram:
http://oldmanhonda.com/MC/WiringDiagrams/CB550.jpg

The colored wires are NOT 12v. Don't hook them to anything other a ground.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #27 on: May 07, 2015, 07:58:07 PM »
How does the sol get power then shouldn't it in theory work then with IGNITION off?
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline calj737

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Re: Slow crank.
« Reply #28 on: May 07, 2015, 07:59:14 PM »
I give up...
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #29 on: May 07, 2015, 08:03:05 PM »
No look. Where the second wire (not yellow red) is out of the Sol goes to power. Right?

Btw that was for a 550
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline Stev-o

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Re: Slow crank.
« Reply #30 on: May 07, 2015, 08:06:40 PM »
Here's a stupid idea: get the correct starter switch.
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #31 on: May 07, 2015, 09:37:36 PM »
Im just thinking i have a solenoid problem and i want to know how to hook this up correctly. Got a button with two wires. Just want to know which wire i need to hook my button up to, and where to put the other wire up from the button. It should work, but if it doesn't i have a deeper problem than me button
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline Badluckhonda

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Re: Slow crank.
« Reply #32 on: May 08, 2015, 12:31:49 AM »
Give power to yellow red and ground green red to frame

Offline calj737

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Re: Slow crank.
« Reply #33 on: May 08, 2015, 02:22:07 AM »
Give power to yellow red and ground green red to frame
Exactly.

If your aftermarket button has 2 wires, connect one of them to Yellow/Red and connect the other wire from your aftermarket button to ground.

Your solenoid should have the Yellow/red connected to it, plus the Green/Red stock wire or, install a ground wire to the solenoid if your stock wire is missing.

The two large studs on your solenoid need to be connected 1-battery POS and 1-starter motor. This has been answered repeatedly and correctly numerous times. If none of this makes sense, take a picture of your solenoid and post it. Same with your button.

If after that happens and you still can't make sense of it, give me your address and I'll drive from VA and connect the wires for you. I can probably do it in less time than it took to type this post.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline PeWe

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Re: Slow crank.
« Reply #34 on: May 08, 2015, 02:41:36 AM »
I had a slow/weak electric starter due to wrong connected ground cable from battery to frrame. (CB750).

I understood and verified it 25-30 years later when I read a thread on this forum. I had connected the ground wire close to the battery, same bolts holding the tool box tray. It was easy to do it.
At last restore I connected it with the rear engine bolt, scratched paint to ensure good contact with frame and engine cases. No weak starter when engine is warm anymore.
I had to use the kick starter and plenty of throttle when engine was hot back in the days scaring the hell out of people at gas stations when the loud 4-1 suddenly screamed as a F1 car. I remember a woman at a gas station in Italy that got here ice cream in her face, a real facial  :P 8)
« Last Edit: May 08, 2015, 09:18:14 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #35 on: May 08, 2015, 04:15:10 AM »
Give power to yellow red and ground green red to frame
Exactly.

If your aftermarket button has 2 wires, connect one of them to Yellow/Red and connect the other wire from your aftermarket button to ground.

Your solenoid should have the Yellow/red connected to it, plus the Green/Red stock wire or, install a ground wire to the solenoid if your stock wire is missing.

The two large studs on your solenoid need to be connected 1-battery POS and 1-starter motor. This has been answered repeatedly and correctly numerous times. If none of this makes sense, take a picture of your solenoid and post it. Same with your button.

If after that happens and you still can't make sense of it, give me your address and I'll drive from VA and connect the wires for you. I can probably do it in less time than it took to type this post.
Dude. The two big posts weren't the issue, it was the little ones. You can stay in Virginia, but i appreciate all the help!
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #36 on: May 08, 2015, 05:21:19 AM »
So this morning before work I hooked it up and described from above and still nothing. I also hooked jumper wires from yellow/red to the positive on batter, and a jumper from green/red and touched several spots on the frame. Still nothing.

Guessing this may be a bad solenoid
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline Bodi

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Re: Slow crank.
« Reply #37 on: May 08, 2015, 06:04:04 AM »
You started out with:

"After market start button, fresh battery.
Slow crank with the button. Fast as hell when i jump solenoid.
Button or solenoid?"

Which would be, almost unquestionably, a failing solenoid. Spinning fast with the posts jumpered says your battery and the starter cabling is OK. Some problem in the wiring harness leaving very low voltage at the solenoid wires might result in a poor, and arcing, contact inside the solenoid and slow cranking. Corroded and burned contacts would do the same with proper voltage.

Now you say the solenoid doesn't even work when you connect battery "+" to one of the two control wires and battery "-" to the other. That's now a failed solenoid.
The story has gotten rather complicated now though, so I'm not sure you did that test.

Don't waste time rewiring the start button if 12V battery voltage across the solenoid wires does not result in a strong click from it - polarity does not matter. Until you have a solenoid that works reliably, testing the button wiring will be near impossible. I would disconnect the starter motor cable from the solenoid post so the starter doesn't run - when doing tests or wiring the button so it works, there's no need to drain the battery that way.

The original problem was probably a gummed up solenoid mechanism and/or corroded solenoid contacts. Properly servicing the thing may bring it back to life: used ones can be good after servicing, usable new replacements can be found at any lawn machinery shop, and new OEM ones are available (crazy expensive compared to a John Deere one though).

Once you have a working solenoid, proceed to wiring the switch.

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #38 on: May 08, 2015, 06:45:50 AM »


Now you say the solenoid doesn't even work when you connect battery "+" to one of the two control wires and battery "-" to the other. That's now a failed solenoid.
The story has gotten rather complicated now though, so I'm not sure you did that test.


This is the test i did this morning trying to pump 12 volts in directly into those two wires. Guessing the PO hooked up the SOL that way just to get by. I will check my battery once more, but it appears as though my SOL it toasted.
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #39 on: May 08, 2015, 08:44:27 AM »
Anyone tried an aftermarket replacement?

http://www.ebay.com/itm/US-Ship-Starter-Relay-Solenoid-Motorcycle-For-Honda-CB750-1969-1978-/171530031528?fits=Year%3A1969|Model%3ACB750&hash=item27effc91a8&vxp=mtr
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline ekpent

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Re: Slow crank.
« Reply #40 on: May 08, 2015, 09:08:48 AM »
Anyone tried an aftermarket replacement?

http://www.ebay.com/itm/US-Ship-Starter-Relay-Solenoid-Motorcycle-For-Honda-CB750-1969-1978-/171530031528?fits=Year%3A1969|Model%3ACB750&hash=item27effc91a8&vxp=mtr
Member Don showed you one on post #20 that he has used if you wanted to rig up a non stock. They easily can be purchased at most hardware and home center stores.

Offline Badluckhonda

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Re: Slow crank.
« Reply #41 on: May 08, 2015, 10:14:44 AM »
The reason I said to ground to frame was to elimanate the button. If your absolutely sure your getting 12v to one of the control wires (e.a using a voltmeter) Then are applying ground to the other you solenoid is no good. Try taking it apart and cleaning it up inside then can get a replacement.

Oh wait another option is just start kicking the darn thing

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #42 on: May 09, 2015, 04:06:13 AM »
New one on the way.
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #43 on: May 13, 2015, 08:08:38 PM »
Got another one, same thing. Tried hooking right to power again and nothing. Here is what I did:



It should be that simple to hear the thing crank
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline Badluckhonda

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Re: Slow crank.
« Reply #44 on: May 14, 2015, 01:15:34 AM »
Make sure that red yellow has power

Offline calj737

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Re: Slow crank.
« Reply #45 on: May 14, 2015, 03:14:25 AM »
the thin black wire on the solenoid carries 12v to it. If you are running it to ground, the solenoid gets no power.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #46 on: May 14, 2015, 04:13:10 AM »
Bad luck and cali...do you see now how you are contradictory here? One of them has got to be a ground right :):):):):)
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline calj737

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Re: Slow crank.
« Reply #47 on: May 14, 2015, 05:02:49 AM »
the Yellow/Red wire coming from the START button is a GROUND. The stock BLACK carries 12v. If you have it isolated from the harness, then connect either to GROUND, not, NEG, and the other to POS.

The only "bad luck or call" is your failure to understand the solenoid is a relay and thus needs polarity to activate the pass-thru of DC current to the motor.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Sdsbassist

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  • Gus, Austin, MN.
Re: Slow crank.
« Reply #48 on: May 14, 2015, 05:26:46 AM »

The only "bad luck or call" is your failure to understand the solenoid is a relay and thus needs polarity to activate the pass-thru of DC current to the motor.

If you actually read the post its referring to "bad luck" (the other guy responding to my post) and "cali" (YOU) who are telling me to do two separate things. I understand the purpose of the solenoid as a relay, and am trying to get it to click. I'm just trying to unhack this so I can run the bike, so when I am getting two different pieces of advice from two different people, it's always good to explore the merits of both arguments.

Does that help you understand?
Gus, Austin, MN.
Current Bike:  75 750F

Past bikes: 76 750K - "Iowa Blue",78 750K Craigslist find - "Black Beth;" 77 CB750K Basketcase, with a 75K engine; 1970 Cb750 K1, "Rosa Luxembourg"
74 cb750, 75 cb550, 77 kawa 650, 81 virago 750, 83 virago 920, 80 Honda Twinstar 200, 71 Honda CT70, 1971 Honda CB750 Rat Project "Black Dahlia Bitsa"

Offline calj737

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Re: Slow crank.
« Reply #49 on: May 14, 2015, 05:59:49 AM »
and your battery is grounded?
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis