Massey 35 23C tachometer question

   / Massey 35 23C tachometer question #1  

Timbo1980

New member
Joined
Jan 13, 2018
Messages
4
Location
Sydney
Tractor
Massey 35
Hi all,

I have a bit of a strange question! I have a Fordson Major (bear with me my question is Massey related!) that I bought a new tachometer for and after installing it on the tractor it reads double the rpm that it should. I tested it with a cordless drill which I know spins at 600rpm and the tach reads 1200rpm, so it appears to be a 2:1 tach. We tried a replacement gauge but it reads double also.

It got me thinking that instead of trying to work out the issue with the 'correct' Fordson tach, maybe I could grab another brand tachometer that works on a 1:1 ratio (ie the rpms that go into the tach are what it reads on the gauge). They all seem to use 5/8 thread connections and the same cable specs so it might be the go.

So, now to my question! I know the Massey 35 with 23C diesel (and petrol for that matter) use a clockwise tach, like the Fordson, but does anybody know if they are a 1:1 ratio? That is, does the cable coming out of the drive on the injector pump spin at crankshaft revs or at camshaft revs? If its crankshaft revs that would mean the tach must be a 1:1 ratio and it should work for my purposes on the Fordson. I also own a Massey 35 with the 3cyl Perkins and I know it is counterclockwise and runs off the crankshaft so presumably that is a 2:1 ratio, and spins the wrong direction anyway. My question is about the 35 with the 23C diesel or gasolene motor.

Any help would be fantastic!!

Thanks,

Tim
 
   / Massey 35 23C tachometer question
  • Thread Starter
#2  
I guess a simpler way to ask the question is: On the 35 with 23C diesel or petrol engine, does the tachometer cable spin at engine RPM or half engine RPM?

Cheers,

Tim
 
   / Massey 35 23C tachometer question #3  
It is driven off the cam so I would guess it as half speed or possibly even less.
 
 
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