CDI broken twice in 1 year

[cristian]

Hi,

I have had 2 Naraku unrestricted CDIs broken in 1 year. I ride a Kymco Like 50 with an Airsal 80bbk, 19mm carb with an 85 main jet and 33 pilot jet, malossi multivar 2000 variator.

I also have heated grips. And I rev my scooter a lot.

Would the problem be that the Naraku CDIs are of poor quality? Or is it something else?

[gsx600racer]

Hard to say. Naraku is usually pretty decent stuff. Maybe try a different brand. Are you running the stock coil or aftermarket ?

[cristian]

Stock coil, yes.
I was thinking that maybe the heated grips were not installed properly.
Or, maybe, I am revving too hard.
But I am not sure how these would affect the CDI.

[GrumpyUnk]

If these are DC CDIs, you may be having electrical problems that are poking the CDI with too low or too high voltage. Might want to monitor the voltage using a VOM at different rpms. If the rectifier/regulator goes nuts you could be feeding spikes to the CDI. I think, but not verified, that the battery taking DC voltage from the regulator/rectifier tends to stabilize the system DC voltage, absorbing higher spikes and providing volts when the rpms sag a bit(idle, etc). If the battery is cooked, shorted, etc, you might have more voltage variation than normal.
tom

[gsx600racer]

I don't know if that model scooter is ac or dc fired cdi. If its ac, there shouldn't be an issue. If its dc, maybe. Plus I don't know how your heated hand grips are connected. If connected to the battery(dc) and the current draw from the grips are high, they might be starving the cdi of power if its dc fired. Another thought, if the the grips heating elements are like "coils" you could be getting reverse voltage spike when you turn them off. You might need to add a flyback diode in the circuit.

Explained:
A flyback diode is a diode connected across an inductor(coil) used to eliminate flyback, which is the sudden voltage spike seen across an inductive load when its supply current is suddenly reduced or interrupted.

Just some thoughts.

[ThaiGyro]

I'm with grumpyunk on this. The likely-hood of two bad ones is very small. Crazy little issues can cause that.
He mentioned the coil...tiny plug wire cracks, spark plug heat range and your accessories can drain voltage to overload the entire system. This is maybe a lucky sign, because the rectifier/regulator goes next, if the cause is a short or too much usage drain.

I had this problem on a road race bike with zero accessories. Lost two pick up coils, like you, but over three races. High compression thumper never had issues, until I got fancy (stupid) with race fuels, and forgetting to change plug heat range to accommodate.

I was running one heat range colder with my 108 octane fuels. (Colder range = hotter) The new fuel put more heat into the engine. (Air cooled 600cc) It was not the octane at 110, but the additives used in those crazy times were, as my friend puts it, "Methyl-Ethyl Bad Shit". The normal plug made that worse, but border line. My bro asked if I changed to a hotter range. Uhhh, that would be NO. Dumb.

I should have known better with this engine. Big, powerful 600 single, with OMG hp. Problem: Air cooled, so hard to start and get warm, (The plug helped) but once warmed up bye-bye!

[lilpinny]

I'd be careful adding too much load to that tiny electrical system. Heating elements suck alot of juice. Did you start blowing CDI's before or after the grips, or before or after you had the shop heating the up more? Usually you can troubleshoot something by looking at what changed before whatever broke, broke.

[cristian]

Nov 16, 2018 6:31:12 GMT -5 ThaiGyro said:

I'm with grumpyunk on this. The likely-hood of two bad ones is very small. Crazy little issues can cause that.
He mentioned the coil...tiny plug wire cracks, spark plug heat range and your accessories can drain voltage to overload the entire system. This is maybe a lucky sign, because the rectifier/regulator goes next, if the cause is a short or too much usage drain.

I had this problem on a road race bike with zero accessories. Lost two pick up coils, like you, but over three races. High compression thumper never had issues, until I got fancy (stupid) with race fuels, and forgetting to change plug heat range to accommodate.

I was running one heat range colder with my 108 octane fuels. (Colder range = hotter) The new fuel put more heat into the engine. (Air cooled 600cc) It was not the octane at 110, but the additives used in those crazy times were, as my friend puts it, "Methyl-Ethyl Bad Shit". The normal plug made that worse, but border line. My bro asked if I changed to a hotter range. Uhhh, that would be NO. Dumb.

I should have known better with this engine. Big, powerful 600 single, with OMG hp. Problem: Air cooled, so hard to start and get warm, (The plug helped) but once warmed up bye-bye!

So, I changed the CDI and it seems this is not the issue because the scooter still cannot start.

I was mentioning the heated grips because I had them installed in a shop. They had to install it twice, because the first time they were not heating enough. And they are connected to the electrical circuit.

Interesting what you mentioned about high octane fuel. I have been putting high octane fuel lately because someone told that I should because I am using a high compression cylinder (80cc Airsal). With standard fuel, I noticed that the engine tends to die at red traffic lights.

So, do you think that the spark plug might be burnt due to the fuel? Could it be just as simple? What spark plug should I use? I am using a CR7HSA.