R90S tachometer ratio 2:1?

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gwagoner
Posts: 27
Joined: Fri Aug 28, 2015 6:35 pm

R90S tachometer ratio 2:1?

Post by gwagoner »

Can anyone confirm if the tachometer ratio is 2:1 or something else?

I have a R60/2 conversion with a 1975 R90S engine and would like to add a tachn. Blue Moon sells tach's for /2 that may work and come in either 2:1 or 4:1

Thank you for the help

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gwagoner
Posts: 27
Joined: Fri Aug 28, 2015 6:35 pm

If anyone is interested, I

Post by gwagoner »

If anyone is interested, I hear that the ratio is indeed 2:1 from my local airhead instrument restorer.

kirkpatrick3890
Posts: 57
Joined: Fri Oct 27, 2006 3:00 am

Re: R90S tachometer ratio 2:1?

Post by kirkpatrick3890 »

The stock rear drive on an R90S is a 33/11 and the corresponding tach reads W-1.112.
Not sure where the 2:1 is about that you mention.
Mac Kirkpatrick
President, VBMWO

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