Whacky Proofmeters?

[timb]

Anyone have any idea what could cause a (new, repro) proofmeter to read off the scale?

Just put a new proofmeter and drive cable in the NAA (it is a 53 Jubilee, family's had it since new). The original had failed long ago.

Started her up and it wants to peg the needle at 2400 rpm+, at idle. Shut it down quick and disconnected the drive. Now we don't have a 6v dwell tach so the idle might be set a little high, but it's in the ballpark and runs like a top.

I think my FIL lubed the cable with dry graphite - and there's no oil leaks off the hyd pump to speak of. Only think I can think of - either this proofmeter was faulty out of the box, or somehow the drive point is not running at the stock speed for an NAA/Jubilee.

We rebuilt the pump, but far as I know these are all stock components. Granddad-in-law was known for "making do" back when this was his tractor, but I can't believe he could have had someone substitute parts from a different series (hundreds or "N's") enough to make a difference and still work.

I sourced the proofmeter through YTMag and they're sending a new one, no questions asked. With a new one on the way - we tried the first one a few times - same result each time. Before we install the new one - I'd like to know if we're missing something obvious here.

 

[Bully]

Does your Proof meter read counter clock-wise? On my old ford, it turns that way off the hyd. pump. you might have got the innards of a clock-wise unit. /forums/images/graemlins/confused.gif When mine went bad, it went direct couple and spun like a top for about a minute. /forums/images/graemlins/shocked.gif Gary

 

[timb]

The dial reads counter-clockwise - and it does look like the drive is trying to take it that way. Problem is - it runs it around the full circle and pegs it north of 2400 rpm!

I'm hoping that we just had the bad luck of getting one with defective guts, I can't believe the actual drive speed could be that far off just from some long-ago and now forgotten parts swapping.

 

[Soundguy]

Those are magnetic coupled.. very close tolerances in there.. I'd be willing to agree with the other poster that it is rubbing or catching and trying to drive direct.

While a hundred series (4gpm? ) pump will fit on the NAA ( 2.9gpm? ) I think they would still be same readout..as the hundred series also use the same red tiger 134ci engine.

Only differences is some hundred series may have had 5spd tranny on some units.

good luck with the replacements. I've bought a couple from Don Barkley at www.just8ns.com with no problems. I'm guessing he gets them from the same place ytmag gets them.

Soundguy

 

[timb]

Word just in from the FIL - the new unit from YTMag showed up today and after a few minutes of installation time - worked perfectly. Guess the first one was bad out of the box.

Least it was simple! /forums/images/graemlins/grin.gif