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Author Topic: New gauges on my CB550 but tach reads low  (Read 1285 times)

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Offline neurotoxin312

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New gauges on my CB550 but tach reads low
« on: April 18, 2018, 04:51:15 PM »
So I picked up a set of these sweet gauges aftermarket gauges made by Emgo. The problem is that it appears as though the Tach never goes above 4000 rpms. After purchasing I realized the ratio on the tach was 4:1 instead of the 20:3.

Two questions:

Is there a difference between the CB750 speedo and the CB550 speedo?

Will I need to return the tach since it isn't a 20:3 ratio? or Can I perhaps use a different tach drive/cable?
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Offline calj737

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Re: New gauges on my CB550 but tach reads low
« Reply #1 on: April 18, 2018, 05:59:54 PM »
750 and 550 are different ratios. Swap them.
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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 flatlander

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Re: New gauges on my CB550 but tach reads low
« Reply #2 on: April 18, 2018, 10:29:50 PM »
Quote from: neurotoxin312 on April 18, 2018, 04:51:15 PM
or Can I perhaps use a different tach drive/cable?

different tach drive won't fit on the camshaft, so no.
different cable won't do anything for the tach ration or reading.
as cal says: send 'em back.
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Offline PeWe

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Re: New gauges on my CB550 but tach reads low
« Reply #3 on: April 18, 2018, 11:35:30 PM »
It is the tacho that is not made for CB500/550. I was very surprised when Z1parts claim their tacho fits both CB500/550 and 750. is it the same gauge?
I have used a Honda CB500 tacho on my CB750 so I know what happen. It will show way too high rpm.
A CB750 tacho on a CB500/550 must be too low. It's strange how the seller can claim that same tacho fits CB750 and 500/550.

Quality issues made me to stay away from the good looking K3-K6 gauges and avoid problems claiming new or money back and impossible to return it. Shipping and customs discussions will cost a lot of energy. I preferred the much more expensive path, old Honda K2 gauges I'll repair.
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CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
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Offline Gordo

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Re: New gauges on my CB550 but tach reads low
« Reply #4 on: April 19, 2018, 12:22:58 AM »
Drop a 650 cam and tach drive in their. Tach will read correctly and gain a bit of pep on the way.
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Offline neurotoxin312

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Re: New gauges on my CB550 but tach reads low
« Reply #5 on: April 19, 2018, 10:12:40 AM »
What about the Speedo? Is that the same between CB550 and CB750?
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Offline Gordo

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Re: New gauges on my CB550 but tach reads low
« Reply #6 on: April 19, 2018, 03:06:29 PM »
Quote from: neurotoxin312 on April 19, 2018, 10:12:40 AM
What about the Speedo? Is that the same between CB550 and CB750?
Yep speedo is the same just tach has different ratio
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Offline neurotoxin312

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Re: New gauges on my CB550 but tach reads low
« Reply #7 on: April 20, 2018, 09:59:08 AM »
Anyone have good recommendations for a tach and speedo dial faces? I can't seems to find a lot of options for the CB550.
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Offline calj737

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Re: New gauges on my CB550 but tach reads low
« Reply #8 on: April 20, 2018, 10:01:21 AM »
Lecram (user Marcel) at CB750 Gauges must have options (or can make them for you).
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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 madmtnmotors

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Re: New gauges on my CB550 but tach reads low
« Reply #9 on: April 20, 2018, 10:07:15 AM »
Dang, if you had posted a week ago you could have swapped gauges with Pyroviking:

http://forums.sohc4.net/index.php/topic,171655.msg1997929.html#msg1997929

He already purchased a replacement. Maybe he'll make you a deal?
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