ignition coil resistances

[yamaha_mike]

Hi

The Seloc and Yamaha manual states the resistances for my primary side of the ignition coil as 0.18 - 0.24 ohms.

I have bought an aftermarket coil labelled as CM61-26 but has a primary side resistance of 2 ohms.

The secondary is 6100 ohms which is a bit higher than the 5700ohm limit also stated in the manuals.

I have measured a genuine yamaha coil as 0.18 ohms and 4700 ohms so it is not my multimeter that is reading funny.

all measurements on secondary done without the resistance type sparkplug cap connected.

my question is, must the primary resitance be as low as 0.2 ohms. will fitting the 2 Ohm ones damage my CDI? why do they sell this as a replacement if its 10 times out of spec?

I have a 85Hp 1991 "688" type motor premix oil.

regards
mike

[madharchod]

it shouldn't damage anything but they have to be compatible and within the standard range of ohm resistance tolerance ,if it fits it will work as the coil are of high resistance anyway

[yamaha_mike]

thanks madharchod

what do you mean? you say it has to be within standard range of ohm resistance. but also say, if it fits, it will work.

the coils I have will fit. but they are not the correct resistance. but they are sold as replacement parts for my motor.

I would like to know if having 2 ohm primary resistance is ok, when the original coils from yamaha require 0.2 ohms. Basic electronics tells me the higher resistance coils are going to limit the current at the primary, which will limit the voltage inducted on the secondary side.

has anyone had success with 2 ohm primary resistance coils? coz i see every yamaha up to 1996, requires 0.2 ohms (Seloc manual)

or am i nit picking??

reason im insisting, is because I am troubleshooting a ignition problem, my old coils were found brocken, but my new ones are out of spec. dont want to introduce a new problem..

[99yam40]

I agree it seems higher ohms might limit the flow

But either try what you have already bought as most electrical parts are not returnable
or buy the correct Yamaha parts.