Automotive Tach on 1cyl

Spoildface

Spoildface

New Member
#1
#1
Hey guys wanted to know if snyone had any experience putting a tach meant for a 4 cyl on a small engine. I've tried tiny tachs but they lag and the no backlight makes it hard to ride at night. I was thinking of finding what rpm on the tack equates to its 1 cyl rpm, and putting a new guage face in, but I don't know how to do that math. Also how is it hooked up? Thru the ground/killswitch lead of the coil? And if its like for 4000 on a 4 cylinder would that make the small engibe be revving at 8000 or 1000?
 
creia

creia

#2
#2
Have you tried the actual "Tiny Tach" (USA made ) brand or the cheap Chinese knockoffs? The former lag very little (almost real time- less than 1/2 second) while the latter lag a couple of seconds.
Michael
 
BBQJOE

BBQJOE

Member
#4
#4
I just don't understand why some company in the business doesn't come up with a digital tach with an analog readout that can operate off the stator, or the plug and a few aaa batteries.

But a small engine puts out AC right? How many volts/amps?

I'm guessing the only way to do it right now would be to install a small generator/alternator and a small motorcycle battery.
 
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creia

creia

#5
#5
Spoildface said:
Both actually. The one i have now is the actual Tiny tach, but still laggy. Its mostly the night riding[/QUOTE

There might be something wrong with your (real) "Tiny Tach" The lag is so slight on the ones we have had it is just barely perceptible and nearly real time.
Michael
Click to expand...
 
MB165

MB165

Active Member
#6
#6
how do the tach instructions tell you to hook it up to a car system? Ignition coil wire or a spark plug wire?
I assume its a inductive type??
Try this:
if it says to hook it to the coil wire, you will have to divide your reading by 4.
if it says a plug wire, then it should be accurate right as it is
 
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FirePowerMinis

FirePowerMinis

Active Member
#7
#7
4cyl car will fire 2x revolution, not 4, and the small engines 1x revolution, wasting a spark on overlap.


I have this, which should work. They do on my sleds.
10-01628.jpg

EGT because I do 2 strokes, and they clog my wide-band.
A CHT may be more practical for most minis.
 
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ole4

ole4

#10
#10
I think it would there is also a equus 8086 that can run a inductive pickup and is a lot cheaper. %9 bucks at some places. You can google 1 cyl analog tach and there are a few snowmobile and 4 wheeler sites that talk about the above two tachs. I bought a few Chinese 10 dollar analog tachs that work fine but seem very slow response. Also all of them need 12 volts so a battery would be required. There was a tach thread here you can search for where there were a few led tachs tested that worked If I;m not mistaken. They look analog when powered on.
 
MB165

MB165

Active Member
#11
#11
yeah that's right ....I didn't take into account the distributor spins at half the crankspeed...
I use a sendec brand hour meter on my minibaja and it doubles as a tach, it takes a reading about every 5 seconds. its accurate, that slow refresh does cause ya to miss out on whats really going on
 
creia

creia

#12
#12
MB165 said:
yeah that's right ....I didn't take into account the distributor spins at half the crankspeed...
I use a sendec brand hour meter on my minibaja and it doubles as a tach, it takes a reading about every 5 seconds. its accurate, that slow refresh does cause ya to miss out on whats really going on
Click to expand...
"...a reading about every 5 seconds" is (by far) the largest lag time I have ever heard of. That tach would be pretty much useless for setting up an engine for performance or for monitoring and avoiding over revving. Are you sure it is really that slow?
Michael
 
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