Heymow - Lawnmower Racing Forum

Engine Help => Briggs Flathead => Topic started by: briggsracer1892 on June 20, 2008, 01:43:46 pm

Title: making a sears dwell tach meter that is made for 8 cyl to work on 2 cyl
Post by: briggsracer1892 on June 20, 2008, 01:43:46 pm
Any suggestions?
I am trying to make the tach work on my briggs opposed (grass cutter because lately it seems to be topping out a too low of a speed.

I already took it in and the guy told me the governer needed to be adjusted

I already messed with and replaced all of the gov. springs with factory replacemnets. how can i make the tach work on a two cyl. even though it is made for an 8 cyl.
Title: Re: making a sears dwell tach meter that is made for 8 cyl to work on 2 cyl
Post by: grantwt on June 20, 2008, 02:23:09 pm
If you just want to check the governor setting you can also get a machinists mechanical tach and hold it on the top or bottom of the crankshaft.

Does a dwell tach take the signal from your plug wire?  If so you just need to divide the reading on the tach reading by two and you have the motor RPM.  Ie a reading of 7200 means you are actually revving 3600.  However I doubt the gauge goes that high so you will probably not be able to do it.

If it takes it from the coil wire (Lead) you need to multiply the RPM by 4.  Ie a reading of 900 is 3600RPM.

If the dwell tach takes a reading from the negative side of the coil, you wont be able to use it.

Does it show my age when I dont know how to use a dwell meter :confused:?!?

Grant

Title: Re: making a sears dwell tach meter that is made for 8 cyl to work on 2 cyl
Post by: 300xdeere on June 20, 2008, 02:23:40 pm
To the best of my kowledge you can't. If you just looking to se your governor then pick your self up a tinny tack, just wrap around your spark plus wire and ground the other wire and your set.
Title: Re: making a sears dwell tach meter that is made for 8 cyl to work on 2 cyl
Post by: racing_guy1985 on June 20, 2008, 03:00:22 pm
300xdeere is right I bought a tiny tach and that all there good for just one steady rpm that the way i would go to.
Title: Re: making a sears dwell tach meter that is made for 8 cyl to work on 2 cyl
Post by: Dylan on June 20, 2008, 03:18:15 pm
and the tiny tach is the only one that works on the opposed engines i belive.. i know the iquues ones dont work on them...
Title: Re: making a sears dwell tach meter that is made for 8 cyl to work on 2 cyl
Post by: briggsracer1892 on June 20, 2008, 05:37:50 pm
How much is the tiny tach?

oh my tach looks like this

http://philadelphia.craigslist.org/pts/685484279.html (http://philadelphia.craigslist.org/pts/685484279.html)
Title: Re: making a sears dwell tach meter that is made for 8 cyl to work on 2 cyl
Post by: 300xdeere on June 20, 2008, 09:25:44 pm
Never seen one of those before, looks a little old but the tinny tach is only about 40$ i believe.
http://www.tinytach.com/tinytach/gasoline.php
Title: Re: making a sears dwell tach meter that is made for 8 cyl to work on 2 cyl
Post by: briggsracer1892 on June 20, 2008, 11:48:38 pm
ok thank you i think i may just have to order one of those.