Who's Else Is Running a Tachometer?

GoldenMotor.com
cory151

cory151

Member
Oct 19, 2010
466
0
16
SoCal
Im running the tiny tach on my S6S Morini, so I can see where my clutch gives me full lock as well as giving me the ability to track performance in relation to RPM (and hours of use).

It comes set to 360 degrees yet the instructions say that most single cylinder engines idle between 1400-1600 RPM. I basically adjusted my Tiny tach until I got that RPM on the LCD which turned out to be 120 degrees. Is this correct? I want to make sure this thing is reading correctly.


Tiny-Tach: Gasoline Tachometers
 
B

Barnfresh

Member
Sep 5, 2011
205
10
18
Nor-Cal
Rotate your flywheel around once. How many times does it spark in that 1 complete revolution? If the answer is 3 times than 120 degrees is correct. If it sparks once per revolution set it back to 360.
 
cory151

cory151

Member
Oct 19, 2010
466
0
16
SoCal
Barnfresh said:
Rotate your flywheel around once. How many times does it spark in that 1 complete revolution? If the answer is 3 times than 120 degrees is correct. If it sparks once per revolution set it back to 360.
Click to expand...
Flywheel? Hmmm, Are you referring to the generator coil?
 
cory151

cory151

Member
Oct 19, 2010
466
0
16
SoCal
Goat Herder said:
I ran a tach on my s6s from day one.
Click to expand...
So how many sparks per revolution did you end up setting yours at?

720 degrees =1 spark per 2 revolution
360 degrees = 1 spark per revolution
180 degrees = 2 sparks per revolution
120 degrees = 3 sparks per revolution
90 degrees = 4 sparks per revolution
60 degrees = 5 sparls per revolution
45 degrees = 6 sparks per revolution
 
D

dmb

Active Member
Dec 4, 2010
1,354
3
36
lakewood ca
i'd say 360 deg, twin cyl would be 180 on 2 strokes. 4 stroke single would be 720deg some older 4 strokers [like harley's, indian's had a waisted spark] so they would spark both holes always when only one was on compression. thats way some bikes shoot flames. i think b&s use a wasted spark too [flames] sorry for rambling on... dennis
 
cory151

cory151

Member
Oct 19, 2010
466
0
16
SoCal
dmb said:
i'd say 360 deg, twin cyl would be 180 on 2 strokes. 4 stroke single would be 720deg some older 4 strokers [like harley's, indian's had a waisted spark] so they would spark both holes always when only one was on compression. thats way some bikes shoot flames. i think b&s use a wasted spark too [flames] sorry for rambling on... dennis
Click to expand...
Ill try setting it back to 360 see how it idles, I wish this rain would let up so I could test her out.
 
UriDead

UriDead

New Member
Nov 21, 2011
83
0
0
Madison, IN.
H

happyvalley

New Member
Jul 24, 2008
784
1
0
upper Pioneer Valley
The inexpensive hour/tachs on eBay come in two configurations, they all look and cost about the same but some have one wire and some have two, the second wire is a ground. The two wire models have a more stable pulse sensor and more accurate rpm reading. Just an FYI, I've bought both but learned it's best to ask sellers which they're selling.
 
Last edited:
Greybeard

Greybeard

New Member
Feb 8, 2011
336
1
0
Sequim WA
Although a 4stroke only fires once every 2 revolutions or 720 degrees, very few singles were ever set up with an ignition system other than the flywheel. Every time the flywheel magnet comes past the coil it will fire the plug. Single cylinder 4 stroke or two stroke should use the 360 degree setting.
 
cory151

cory151

Member
Oct 19, 2010
466
0
16
SoCal
This tach is worthless on the Morini Im gonna try it on my 99cc HF instead doesn't matter how many wire raps you give it or what you set the degrees to (I've tried every setting) it reads wrong for a few minutes then proceeds to shut down with a U110 code.
 
You must log in or register to reply here.
Top Bottom