Cheap Tachometer Help and Info Please

[Pimpy1]

I installed a cheap tach on my Super  8 2t 50 and not sure if my readings are correct.  Shows idol around 900rpms. 3500rpms range cruising at 35mph and 5200rpms max on big downhill at 48mph gps max speed.

not sure if I have it set correct. I can set tach to read 1 pulse per fire or 2 pulse per fire. 

So I'm not sure if my max rpm is 5200 or 10,400 rpms.

This is the tach i bought.

 http://www.amazon.com/gp/product/B0049IFX56/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0049IFX56&linkCode=as2&tag=kinderinfo1-20

[ophelia]

It looks like your tach is showing half your revs. Try one pulse per fire?

[Pimpy1]

I didn't think my mostly stock scoot was capable of turning over 10,000 rpms.  What should a 50 2t at  idol rpms be.  That is with 9 gram rollers. If I put in 6 gr rollers the thing might over rev to 15,000.

[Stig / Major Tom]

What's you manual say for idle speed?
Mine (LIKE200i) says 1700. I've been reading 920 on my cheap tach. So I've got it set wrong, too!

Thanks Surgeon for getting us straight!

[Pimpy1]

Idle should be 1850rpms by owners manual. So if I doubled my reading that sounds about right.  So I guess I was really turning over 10,000 rpms top end. Dang!

[ophelia]

I ordered a pair of those tachometers from eBay a few days ago. How do you like it? How fast does it update?

[Pimpy1]

About a 2 second delay on the reading but easy to put on.  I didn't even mount it to the scoot. Just rapped the cord around the spark plug wire 6 times and hung it off the carry hook so I could read it while driving. You can take it on an off in under 2 minutes and not have to put holes in your scoot.

Works good for testing.