Author Topic: Tach for cb750a  (Read 1791 times)

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Offline hazardus320

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Tach for cb750a
« on: January 11, 2014, 07:15:30 AM »
Hey guys,

I was wondering if you guys had any suggestions for a tach.   I know it will come in handy when adjusting the carbs, and I think it would be nice to know when driving around as well.   Thanks in advance.

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Offline notn

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  • my trike..1977 Honda 750a wheelchair access
    • world according to neal of the north
Re: Tach for cb750a
« Reply #1 on: January 12, 2014, 12:35:12 PM »
I wound up putting an older (70's) vintage Sun Supertach on mine, mounter it right between to speedo and idiot light housing.  You do need to make a diode (I used 40xx series) because the tack is designed for 1 coil, so you split the wire off the tach and put a diode in each line to each coil.  I did buy a smaller new 10,000 tach that was supose to work with dual coils but I can't make it work, so watch for tachs that will work with 2 coils.  I don't know about on a bike but I don't like the digital readout tach, the "sweep" type would work fine I think but it iss too hard to read a rapid moving digital, especially when the sunlight hits it just right.  thats my thoughts anyway 
Neal Chamberlain
Neal - of - the -North
North Powder, Or
www.notn.org

Offline xntrik

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Re: Tach for cb750a
« Reply #2 on: October 13, 2014, 04:26:27 AM »
I use a little cheap-0 hour meter/tach combo I got off ebay for like $15. Just wrap one wire around the plug wire and set the number of sparks on that wire per crank rotation and it's done. Also use same unit on other bikes/small engines.


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Offline MidnightLamp

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Re: Tach for cb750a
« Reply #3 on: October 13, 2014, 09:09:06 AM »
You can just fit a K/F valve cover with tach gear and run a stock SOHC4 750 tach.
'75 CB750 - Racer
'69 CB350 - Racer
'68 Enfield 350/440(flat top) - Steet
'54 Enfield 350 - Resto
'74 Commando 850 - Restomod
'67 Enfield 750 (TT7) - Resto

Offline xntrik

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Re: Tach for cb750a
« Reply #4 on: October 13, 2014, 12:26:59 PM »
Midnightlamp, have people done this? Is this confirmed? My next A is going to be a bobber, and I'd love to have a mini tach on it.....


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Offline MidnightLamp

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Re: Tach for cb750a
« Reply #5 on: October 13, 2014, 10:32:09 PM »
It's the same head (392) as a K7/K8, same valve cover completely with the tach drive, it's just not machined in (you can see where it goes on it and the gear bits). The cam has the drive gear as well.
'75 CB750 - Racer
'69 CB350 - Racer
'68 Enfield 350/440(flat top) - Steet
'54 Enfield 350 - Resto
'74 Commando 850 - Restomod
'67 Enfield 750 (TT7) - Resto