Author Topic: Tachometers  (Read 611 times)

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mswyka

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Tachometers
« on: March 11, 2018, 02:10:23 PM »
We have two  sleds with  tachometers that are not working.  They worked initially but quit.

if  everything else on the sled  is working properly, does  this  just  mean that the tach is bad and  needs to be  replaced?

Is there anything on the sled, or  any condition, that could contribute  to tach failure?
Intruders:  1978, 1979, 1980, 1981 Custom
Invaders:  1979 340, 1980 440, 1980 440 TOC Custom
Projects:  1979 Invader 340, 1980 Invader 340, 1979 Intruder 440, 1982 Intruder 440, 1980 Drifter 340 F/C, 1972 Panther 303 ...

gixxer6

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Re: Tachometers
« Reply #1 on: March 11, 2018, 04:23:24 PM »
The tachs are a simple pulse counter, it counts the pulses created by the lighting coil.  If youíre lights are working and you have a good connection the Iíd say the tachs are bad. 

I find this odd as I have never seen a tach that didnít work at all.  Usually they just get really bouncy and need to be replaced. 

mswyka

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Re: Tachometers
« Reply #2 on: March 12, 2018, 02:14:36 PM »
The one on the green sled bounced for a time and then decided not to work at all.  I am starting to see a trend with this sled with parts working and then not working - first the CDI, then the fuel pump, and not the tach.   Actually, the speedometer is not working either but I think that I put a 79 adaptor on the sled by mistake.
Intruders:  1978, 1979, 1980, 1981 Custom
Invaders:  1979 340, 1980 440, 1980 440 TOC Custom
Projects:  1979 Invader 340, 1980 Invader 340, 1979 Intruder 440, 1982 Intruder 440, 1980 Drifter 340 F/C, 1972 Panther 303 ...

gixxer6

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Re: Tachometers
« Reply #3 on: March 12, 2018, 03:09:47 PM »
I have a mess of good used tachs if you are in need (knowing you, you probably have several spares in your magical Kaw shed!).  I might even be able to scrounge up a NOS tach if you want to get fancy...

mswyka

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Re: Tachometers
« Reply #4 on: March 13, 2018, 07:57:09 AM »
How did you know that we would have spares?  No NOS parts (with the possible exception of a pair of 340 Invader head gaskets), but many spares.  Now to find the time to make the swap.
Intruders:  1978, 1979, 1980, 1981 Custom
Invaders:  1979 340, 1980 440, 1980 440 TOC Custom
Projects:  1979 Invader 340, 1980 Invader 340, 1979 Intruder 440, 1982 Intruder 440, 1980 Drifter 340 F/C, 1972 Panther 303 ...

mswyka

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Re: Tachometers
« Reply #5 on: March 14, 2018, 05:33:43 PM »
Home from work a little early so I stole some time to work on the green sled.  The speedometer adaptor was a "left" adaptor and should  have been a "right" adaptor - rookie mistake.  So I put on the best looking one that I had, started out and managed to hit 100 mph across my back yard.   Back to the garage - it was a 1:1.375, found a 1:3, swapped it in and now she is running as expected, topping out around 40 across the back yard.

Oddly enough, when starting the sled the tach  was reading and telling me that the primary was kicking in at about 3800.  Across the yard I glanced down at the tach only to see that I was making zero rpms again.  She goes quite well for zero rpms.  I  think it is time to try another tach.

But I will say that she is running better with each trip.
« Last Edit: March 14, 2018, 05:48:23 PM by mswyka »
Intruders:  1978, 1979, 1980, 1981 Custom
Invaders:  1979 340, 1980 440, 1980 440 TOC Custom
Projects:  1979 Invader 340, 1980 Invader 340, 1979 Intruder 440, 1982 Intruder 440, 1980 Drifter 340 F/C, 1972 Panther 303 ...

Habbeli

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Re: Tachometers
« Reply #6 on: March 24, 2018, 11:12:40 AM »
I just have the same problem, It's my third one that's broken now.
It seems to be poor quality on them  :-\
Where does the white go when the snow melts :-))

sprocket

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Re: Tachometers
« Reply #7 on: March 30, 2018, 06:12:36 AM »
I've had good success with EGT tachometer they make other tachometers that you can add in magnets (pick ups) for reading rotation off the jack shaft or off your primary clutch

mswyka

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Re: Tachometers
« Reply #8 on: March 30, 2018, 06:54:41 AM »
I've had good success with EGT tachometer they make other tachometers that you can add in magnets (pick ups) for reading rotation off the jack shaft or off your primary clutch

This is interesting information.  Thank you.
Intruders:  1978, 1979, 1980, 1981 Custom
Invaders:  1979 340, 1980 440, 1980 440 TOC Custom
Projects:  1979 Invader 340, 1980 Invader 340, 1979 Intruder 440, 1982 Intruder 440, 1980 Drifter 340 F/C, 1972 Panther 303 ...

sprocket

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Re: Tachometers
« Reply #9 on: March 31, 2018, 06:43:57 AM »
There is also a company that makes a hand held devise that reads Rpms (laser point) they also make another one that you can hold against your track (not for me) to figure out how fast your track turns we used that style for making conveyors we needed to know how fast the belt went for their products to be pushed along