tach and hour meter

[lippy]

tach and hour meter

hi tractor people
just wanted to know if anyone has checked there hour meter to see if it regestered the right time running, i checked mine and when it said it had been running an hour ,it was realy an hour and fifteen minuits,would this also through the tach off ,maby it is metric time,lol

have a good day today and a better one tomorrow

 

[pruntyc]

Re: tach and hour meter

That only tells the correct time if you are running at about 2300rpm, the place the red line in on the meter. If you are running slower speed on the tach, it will not show the correct time. Or if you are running faster rpm, it won't show the correct time. And it may not be perfect, or could be off a little, but generally not too much, or at least not enough to really matter. It sounds to me like you weren't running the right rpm to be off that much.

 

[lippy]

Re: tach and hour meter

thanks for the reply,it sounds like you are right

 

[Bird]

Re: tach and hour meter

Larry, of course Dick's right, but it just depends on which kind of hourmeter the tractor has; some have one, some the other. And it's not even consistent within a particular brand.

For example, I had a 1995 Kubota B7100 with an hour meter that was simply an electric clock that ran anytime the key was turned on. That gives a pretty good indication of the time the tractor has run, but no indication at all of how many revolutions the engine had made; i.e., what rpm the engine had been running at. And since the "kill" switch worked by pulling the throttle lever all the way back to shut off the fuel, it would have been possible to kill the engine, leave the key on, and leave the hourmeter running (one of our forum members once mentioned leaving his on overnight, I believe). On the other hand, it would also have been possible to turn the key off, thereby stopping the hourmeter while the engine continued to run (of course I think you also would not be charging the battery if you did so).

Then I had a 1999 Kubota B2710 with the other kind of hourmeter. It was dependent upon the rpm the engine is running (as yours apparently is). It would register an hour in an hour running at PTO speed, but if you ran it at half PTO rpm, it would only register 30 minutes in an hour. And since turning the key off killed the engine (electric solenoid to shut off the fuel), the hourmeter could not be as easily fooled as with the clock type.

Personally, I prefer the latter type.

 

[Soundguy]

Re: tach and hour meter

Too bad tractors don't incorporate both methods.. a mechanical tach/hourmeter.. and an electrical one just counting 'up-time'.

The difference between the two gives you a real idea of tractor usage ( close times mean the tractor was run at rated speed most of its life.. like as for a stationary power unit.. etc.. )

Soundguy

 

[mountain_man]

Re: tach and hour meter

Most light airplanes have both a "Hobbs" electric clock (starts/stops on oil pressure) and a Tachometer clock (which was equal to clock time at cruise power - I think). Differences were about 10-15 percent or so. We billed airplane time based on Hobbs time, but maintenance intervals were based on Tach time (per the FAA).

 

[lippy]

Re: tach and hour meter

THANKS AGAIN TO YOU ALL FOR THE REPLYS,I AM LEARNING A LOT.