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Author Topic: Speedo drive problem  (Read 1746 times)

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Offline StevieMac

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Speedo drive problem
« on: August 04, 2006, 12:15:57 PM »
The speedo died on my '78 750 a while back.  The speedo itself is fine and I've put on a brand new cable.

The problem is whatever is inside the hub of the wheel that engages the speedo drive itself.  The speedo drive appears to be good. I've tried 3 different ones.  Turning them by hand they work fine but when I put them on the wheel they don't really work.  With the drive connected you can spin the wheel and the speedo drive will turn the shaft but ANY resistance applied to it (like turning the cable) stops the drive from working.

So what piece is in the hub that connects into the speedo drive?  I haven't tried pulling the hub apart to take a look.  I was hoping to locate a replacement part before I got everything disassembled.
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Offline OldSchool_IsCool

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Re: Speedo drive problem
« Reply #1 on: August 04, 2006, 01:50:26 PM »
You can look at the parts fiches at

http://www.mrcycles.com/fiche_select.asp?vcc=Motorcycles&mfg=Honda#SDOWN

Search through the different fiches for your year and model.  Part numbers are listed too.  MRCycle sells them, but you might find better prices at www.servicehonda.com
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Offline StevieMac

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Re: Speedo drive problem
« Reply #2 on: August 04, 2006, 01:59:07 PM »
Hmm, looks like possible part 5 shown in the diagram but I'm not sure as I'm not positive which piece actually engages the speedo drive.

Anyone know for sure?
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Offline grumburg

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Re: Speedo drive problem
« Reply #3 on: August 04, 2006, 02:37:41 PM »
Make sure the wheel spacer is in place outside the rotor and there is no sideplay in the wheel. A friend bought a 550 and brought it to me because the speedo didn't work. Someone had replaced the front wheel and did not use the spacer. Only thing holding the wheel in place was the rotor. Speedo drive needs to make contact with the 2 little dents on the inside if the hub cover or it will just slip. Drive should not rotate.
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Offline grumburg

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Re: Speedo drive problem
« Reply #4 on: August 04, 2006, 02:40:01 PM »
Parts 6 and 7 on diagram. Spacer is part 2
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Offline Bob Wessner

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Re: Speedo drive problem
« Reply #5 on: August 04, 2006, 02:43:16 PM »
Quote from: grumburg on August 04, 2006, 02:40:01 PM
Parts 6 and 7 on diagram. Spacer is part 2

I agree. Also, make sure the wheel is snug/torqued correctly on the axle. The speedo pick-up unit shouldn't spin.
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Offline SuperVel

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Re: Speedo drive problem
« Reply #6 on: August 06, 2006, 03:29:26 PM »
By experience I found out that there is a stamped part inside of the front wheel on the 750F2.  There are ears that engage the mechanism on the inside of the speedo gearcase.  The part crushes quite easily if the ears are not in the slots in the gearcase.  The wheel can be removed and the stamped part can be straightened. 

Good Luck

Marty
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