WOT stalling Honda c200

Davis2x1

New Member
My Honda C200 has been having problems with full throttle stalling. I installed a CP electronic ignition. Bike idles well and mid-speeds. When I try full open engine stalls. Rebuild carbs twice, tried various needle settings. Currently center position with #95 main jet.
So I am tinkering with the bike. Stalling. All of a sudden the alligator clip from battery to ground drops off. The engine takes off with more power than ever. On and off the throttle alls OK. Bike stops. No neutral light nor headlight ???
It appears my carb problem is actually electrical. They say not to run without a battery but why does the engine run better without it?

Thanks for any suggestions.
Dave
 

69ST

Well-Known Member
Gonna take a flyer on this one, since I don't know the first thing about your model. If it requires a battery, like a CL70, then I'd suspect a combination of weak battery and dead/dying rectifier...possibly a bad ground, as well.
 

Davis2x1

New Member
Removed CP ignition and installed old points. Had a 6 volt coil from my BMW airhead and rig greg it up. Engine started and ran well up to full throttle. Looking for a low impedance coil. The Bosh unit I have is 1 ohm on the primary.
Thanks for your help
Gonna take a flyer on this one, since I don't know the first thing about your model. If it requires a battery, like a CL70, then I'd suspect a combination of weak battery and dead/dying rectifier...possibly a bad ground, as well.
 

69ST

Well-Known Member
Ah...the coil change, or lack thereof, went right past me.:confused: Yep, HT coils are very different for beaker point vs CDI.

Glad you were able to sort this out quickly.(y)
 

Davis2x1

New Member
Ah...the coil change, or lack thereof, went right past me.:confused: Yep, HT coils are very different for beaker point vs CDI.

Glad you were able to sort this out quickly.(y)
RacerX,
Thanks for your reply. You mentioned the difference between CDI and points coils. I installed CP ignition on my CB350 and it worked fine. 12 lvolt system. My C200 has a 6 volt system. What is the difference between a CDI and point coil. Higher or lower impeadance required.
I am going to check the dwell on my point ignition just to see what it is. Many talk about a 3 milliseconds dwell.
Dave
 

69ST

Well-Known Member
I doubt that the charging/lighting system voltage has any, direct, relationship to the ignition...unless it's battery ignition. And I haven't taken a dwell reading on anything since the late 1970s. While I do want to understand the principles behind, well, just about everything...I also realize that there are practical considerations which keep things from spiraling into a migraine. Specifically, here, it's breaker points vs CDI and 12v vs 6v. There are very few choices in manufacturers so, it's really just a matter of sourcing the parts as a complete assembly/system, imho; ignition either works, or it doesn't. It's not like there's anything that can be adjusted, as with a carburetor, for example. And, with the exception of the CL70, all of the engines that will bolt into z50/CT70 mounts have magnetos...12v/6v doesn't make any difference; with these engines, the terms refer to the lighting/charging coils. It's only used as convenient, if somewhat misleading, nomenclature. The 6v engines came with breaker point ignition, the 12v versions CDI...the alternator assemblies are completely different, with nary a single part interchange between them.

That said, breaker point ignition vs CDI can be viewed as comparing spark output between household 120v current and static electricity you'd pick up in a dry household environment. They'll both produce a snappy, blue-white, spark but...the former has much more current (amperage) whereas the latter has much higher voltage. Doesn't take much wattage to produce a healthy spark, just voltage. High voltage + low current is easier to to handle with simple, small, electronics. Breaker points, OTOH, are physically suited to higher current draw, as evidenced by the hard alloys used for the actual contacts. Cutting to the chase...CDI coils are smaller than breaker point ignition coils, both primaries & secondaries. My guess is an equal, or greater, number of turns, using smaller gauge wire wound around thinner cores. The biggest difference is inductance. Impedance values are minuscule, almost useless (without sophisticated equipment and knowledge) other than verifying a dead coil. The bottom line, I've always viewed these ignitions as complete systems...primary coil, pickup, CDI module, secondary coil...I've seen too many problems resulting from mix & match. I apologize if this answer isn't what you were hoping for. It's a case of basic practicality, i.e. the best parts to use are the ones you can get which also work, over everything else.
 

Davis2x1

New Member
RacerX
Answered like a true politician. I received the new pick-up. Installed same using my old BMW 6 volt coil. Bike ran fine thru all throttle ranges . The coil I used had a 1 ohm primary resistance. Now to reassemble all the wiring.
Thanks for your help and ride safe.
Dave
 
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