I'm at wits end trying to resolve a problem with an R100RS (1983).   There's a heat-related issue that raises the idle/tickover and causes rough running when hot. I've gone through the carburettors a number of times... nothing there that suggests they're the culprits. Now I'm wondering if the coil(s) are failing when they get hot. I've a set of coils from my K100. Could I plug them into the R100RS to verify if the presently installed coils are defective?    I want to avoid damage to related electrical bits on the R100RS, as I'm in no position to throw money at new parts just now. I'd rather be riding than repairing. TIA for any insights.

On my old R80RT, 1986, I had running problems with that when first bought. So converted back to points ignition with the 'bean can' and one K100 coil under the tank. Ran for 10 years in my ownership without a hiccup and no doubt is still running with this setup now. John

brickrider wrote:I've a set of coils from my K100.  Could I plug them into the R100RS to verify if the presently installed coils are defective?    I want to avoid damage to related electrical bits on the R100RS, as I'm in no position to throw money at new parts just now.

Coils off an Airhead, circa 1983, are 1.5 ohms primary resistance. An 'early' K coil has about 2.6 ohms primary resistance. So, a short burst wouldn't hurt a thing, i.e., your Airhead's ignition module.

Thanks for the replies. 
I understand then, if the resistance is a tad greater, no short-term damage to the ICU is to be expected.  For optimal performance however, I should use coils of lower resistance. Correct?