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Kid Kart Tech Tip
Identifying Comer C-50/51 Ignition Systems
One of the confusing aspects of dealing with the Comer C-50 and C-51 engines is dealing with ignition parts when they need to be replaced. There are 4 versions of that engine that I am aware of.
First were the very old style C-50 engines that have a ferrous material cylinder liner. That engine is fitted with an ignition made by Selettra. These are commonly called the "ignition with the blue coil". The flywheel that went with that coil has fins on it that are straight. This version has the push button kill switch. The word Selettra is molded into the blue coil and the flywheel.
The second version of the C-50 engines has a cylinder with the chrome/nickasil coating on the cylinder. That engine sometimes has a flywheel with straight fins and I've also seen it with the newer Selettra flywheel with curved fins. This information is based on what I have observed on engines that have been sent to me. I don't know for sure if they originally came from the factory that way. This version also uses the push button kill switch. The word Selettra is molded into the blue coil and the flywheel.
The third version is the older style C-51. It also has the plated cylinder. That engine has the Selettra flywheel with the curved fins and the newer black Selettra coil. The word Selettra is molded onto both the coil and the flywheel. This version uses the rocker type on/off switch.
The current version of the C-51 is almost identical to the third version. The exception is the brand of the flywheel and ignition coil. All of the replacement parts that I've received for these have Volano marked on the box so I'm assuming that is the brand of the most recent ignition vendor for this engine. Of all of the different versions, this one is my personal favorite. I have been able to consistently get slighlty better dyno numbers from these engines.
Identifying which ignition you can be difficult if you don't know what to look for but it is easy if you remove the flywheel and look at the back. The picture below will make identification easy.
The flywheel on the left is the backside of the old style Selettra with the straight fins.
The fylwheel in the middle is the newer style Selettra with the curved fins.
The one on the right is the current production Volano also with curved fins.
The question that comes up at this point is what parts are compatable with each other.
If your only concern is just making the engine run, either Selletra coil will run the engine with either flywheel. The difficulty comes when you try to shut the engine off. If you try to use the black Selettra igniton coil on a C-50 with the push button kill switch you will either have to hook up an external toggle kill switch, use a cable tie to pull the boot off of the spark plug or choke the engine to shut it off. Those are all a pain in the butt but the engine will run ok.
The blue Selettra coil will also run the engine with either Selettra flywheel but once again you run into kill switch issues. The picture below shows a small wiring harness that I made up to make the blue coil work on C-51 engines with the rocker kill switch. This shows where I soldered a wire to the brass button that the pushbutton contacts to shut the engine off on C-50 engines. Any good tinkerer can duplicate what I did by looking at the picture.
The newest style Volano ignition coil will not run the engine with either Selettra flywheel. You must use the Volano flywheel with it. Knowing this is crucial when you want to order replacement parts.
Please note that mixing and matching these parts may or may not be legal in your club or track. Personally I don't see what the issue is there. Some people think that using the blue coil will give better performance but from my testing I have not seen any significat difference in performance between the two different Selettra ignitions although there are considerable gains in top rpm by advancing the ignition beyond the legal WKA numbers regardless of which version you have. The trade off with extreme advancing of the ignition is loss of low end performance.
By the way, Bergfelt Racing Enterprises, LLC will be happy to supply your Comer C-50/51 parts and help you with your kid kart technical issues. Just call or e-mail for more information or a price quote.
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