Add a Tachometer

[Quimrider]

Like Easy Rider said, It's far more simple and cheaper to do dual fire ignition. If you wanted to do single fire you would need a cam position sensor so the ignition module can tell the difference between TDC of the combustion stroke and TDC for the exhaust stroke. Remember in a 4 cycle engine the piston only fires once every two revolutions.

[alantf]

Originally Posted by Quimrider

Like Easy Rider said, It's far more simple and cheaper to do dual fire ignition. If you wanted to do single fire you would need a cam position sensor so the ignition module can tell the difference between TDC of the combustion stroke and TDC for the exhaust stroke. Remember in a 4 cycle engine the piston only fires once every two revolutions.

I remember in the old days, working on cars with the old fashioned mechanical breakers, that had to be changed every few thousand miles. They worked fine (until the contacts started pitting), so I would have thought that in this day and age, someone would have come up with a cheap solid state version that would do the same thing, but in a better way. :??:

[Palaka]

WOW look what I started :hide:

[alantf]

Originally Posted by Palaka

WOW look what I started :hide:

That's what makes this site so much fun.

[Water Warrior 2]

The simple and cheap design is reliable and is probably a lot more desired in 3rd world countries where the GZs are a primary transport device. The GZ is what it is and we are actually served well by it. The KISS principle is alive and well.

[Quimrider]

Originally Posted by alantf

I remember in the old days, working on cars with the old fashioned mechanical breakers, that had to be changed every few thousand miles. They worked fine (until the contacts started pitting), so I would have thought that in this day and age, someone would have come up with a cheap solid state version that would do the same thing, but in a better way. :??:

They have They've replaced the mechanical complexity of the gears driving a distributor with a Hall effect or VR sensor on the fly wheel that tells the magical electronic ignition box when the piston is at TDC. Following the KISS principle we don't care whether it's on the combustion stroke or exhaust so we'll just fire the plug on both. If we did care we'd have to violate the KISS principle and add a cam position sensor to determine when the piston is at TDC on the power stroke. This does have some advantage when it comes to multi-cylinder engines and fuel injection.

The magical electronic ignition box takes care of ignition advance based on rpm. On more advanced systems there might be a throttle position sensor that combined with RPM can calculate engine load and adjust ignition advance accordingly. You could get more fancy (accurate) measuring engine load by adding a manifold air pressure sensor to the sensor mix. This magic in the ignition box replaces the vacuum advance or centrifugal advance from distributors of yesteryear

So essentially a cheap crank position sensor and electronic box replace the old school distributor.

[Sarris]

Just get the one on eBay I suggested. Its for the single cylinder S40 nee Savage 650.

It will work fine because which ever it is (single or dual fire, who cares really??) it fires the same as the GeeZer.

[Palaka]

that works for me appreciate everyones help

[Quimrider]

I tried to make the following edit to the main post, but got a database error. I sent the admin an email. I found the tach elsewhere for a pretty good price. I"m buying one for one of my bikes.

[strike:34jpz9ly]About 57 dollars after shipping. [/strike:34jpz9ly] This is not a fancy
tach. just a plain and simple 8K RPM tach.

Update 08/17/10: Powersportsoutletstore.com has entered the dustbin of history.

I found what appears to be the same tach at BKrider for $39.99 + $8 and change shipping.

[5th_bike]

Regarding the smaller (1 7/8 " diameter) tach, Dennis Kirk still exists but at the tach they mention "This Product is No Longer Available"

They still have similar ones, for $99.99. A bit steep.
http://<br /> <a href="http://www.de...Id=&mmyId=</a>

If you want one please search for "Drag Specialties 1 7/8 Tachometer"