Hello,

I have Aeon Cobra 180cc atv (1 cylinder 4 stroke with carburetor) and I want to install a tachometer to set my iddle to the correct rpms (1800). In some tachometers you must set the PPR (Pulses Per crankshaft Revolution). For my atv which is the correct setting, 0.5 or 1 ?

I found this tacho on ebay:
Works Connection Tach Hour Meter Gauge Motorcycle ATV Tachometer Engine NEW | eBay

Will this tacho calculate the correct rpms?

 

I know nothing about aeon cobra quads.

Most chinese quads have the ignition system triggering mounted on the flywheel instead of the camshaft. On a four stroke engine this leads to a curiousity - every revolution of the engine will produce a spark even though a four stroke engine requires a spark every other revolution (on the compression stroke, but not the exhaust stroke). This is sometimes referred to as the "wasted spark" setup. It is done solely for simplicity in design. Having an extra spark at the top of the exhaust stroke does not harm so why not? It's easier and cheaper to build an engine that way.

So your tachometer must be programmable so that it knows that a spark occurs every engine rotation instead of every other (or not if your aeon is different from most chinese quads). So you probably will want to set your PPR number to 1 (not 0.5). In other words you need to tell the tachometer that you have a two stroke engine - even though you don't.

I looked briefly at your link -I didn't see any explicit references to being able to set the PPR to 1.0 or 0.5. So make sure you can do this before you buy.

 

Thanks for the reply Lynn.
My atv engine is like a GY6 engine. I was searching in the internet and I found that Gy6 engines have PPR 1.0.
The tacho from works connection can set the PPR either 0.5, 1.0 , 2.0.

I also found this tacho :
Electronic Specialties 328 - EZ Tach +PLUS | eBay

Has anyone use one of these? Which one of the 2 to buy?

 

So a PPR of 1.0 is correct.

I couldn't find any reference on either link that says you can set up various PPR numbers. Maybe I just missed it. In any case make sure you can set the proper PPR, and after that it is just company reputation. Checking eBay's feed back helps, but make sure their feedback is largely based on selling quad stuff, and not womens shoes and cheap watches. You want them to at least have a clue about what they are selling. Ask questions to the vendor, and analyze their response...

 

I think that I will buy EZ tach 328 plus. I sent to the company an email and the sent me a user manual. The tach with settings 2 stroke - 1 cylinder is reading 1.0 PPR. Also I like the wirelless reading function of this tacho. It will be very easy to set the correct iddle speed.
Thanks for the info Lynn!

 

You're welcome, and let us know how it works...

 

Today I received EZ tach 328 plus. It works great with settings 2 stroke-1 cylinder for my Aeon Cobra 180cc atv. Good quality product and with 1 year warranty. I recommend it to anyone who want to see the rpms of their motorbikes etc.