(really) Inexpensive Tachometer

[wingnut2000]

bought me one. how long did it take to get yours?

[Pocono Country Boy]

Originally Posted by wingnut2000

bought me one. how long did it take to get yours?

It was shipped next day...but the post office took 4 days to get it to me on the other end of the state! Go figure!

[capthump1]

Got mine today, what do I set it for? I have a workhorse with a 350 4 stroke. How many times does the ignition fire per rev? Also can I extend the wire?

[BrewCityMusic]

I got mine today and also had to extend the wire - I took a little time and soldered it together with the extension and shrink-wrapped it and it seems to be working ...

[Dave Box]

Originally Posted by capthump1

Got mine today, what do I set it for? I have a workhorse with a 350 4 stroke. How many times does the ignition fire per rev? Also can I extend the wire?

Well I am a 2 cycle man myself but I am pretty sure that the 4 cycle is triggered from the crankshaft and fires once per revolution. (The extra spark during the exhaust stroke is simply surplus to requirements). Set it to 1 per and see if the result is what you expect.

Curiously enough the 2 cycle engine should be set to 2 per as there is a second magnet to provide the spark in reverse however if you set to 2 then the rev counter has you doing 2000 rpm flat out which is clearly incorrect. I assume, and perhaps brighter minds can correct me, that the second spark is so close to the first that the rev counter trigger has not reset. Anyway I have had mine for a couple of months and it works just fine.

[Pocono Country Boy]

I don't know about your four stroke Cap, but I set mine for "once per revolution" for my 88 2-stroker and wrapped the pickup wire four times around the spark plug wire right at where it attaches to the coil and it works great.

[capthump1]

I'm thinking its 2. Its probably like a harley 1 coil fires both cyl each time.

[Pocono Country Boy]

Originally Posted by capthump1

I'm thinking its 2. Its probably like a harley 1 coil fires both cyl each time.

Give it a shot!

You can always change the setting if it doesn't seem right.

[rib33024]

Originally Posted by capthump1

Got mine today, what do I set it for? I have a workhorse with a 350 4 stroke. How many times does the ignition fire per rev? Also can I extend the wire?

http://wikicars.org/en/Otto_cycle

YouTube- How a 4 Stroke Engine Works

YouTube- How a 4 Stroke Engine Works

[wingnut2000]

I got my tachometer today. where did you mount yours? Does the wire need to be stripped before it is wrapped around spark plug? Can i strip the wire and use connectors to add more wire?