replacing coils

[Reggybrat]

i have a 81 xs650s which has a dead left hand coil, trying to replace it but cannot find a 81 model coil but have found a few 80s model close by me, just wondering if im up to run a 80s model coil along side the 81 model without any problem. the difference between to two being the 80s model is 4 ohms and the 81 is 5 ohms. also what if i brought 2 of the 80s model so the ohms were the same.
Thankyou in advance

 

[TwoManyXS1Bs]

Welcome to the forum, Reggybrat.

The 70-79 models used points with two coils.
The 80-84 models use TCI ignition with a single coil.
Unless it was an European version.

So, we need a better description of your bike...

 

[Reggybrat]

Its an 1981 xs650 s, i believe it must be a euro version as it definitely has two coils, although im not sure if it was modified as it looks like the loom has had some work done to it

 

[TwoManyXS1Bs]

Does it have points?

 

[Reggybrat]

Just checked and it has twin points

 

[TwoManyXS1Bs]

Then, it seems that you could just use 70-79 coils.

 

[XSLeo]

Here state side the70-79 coils were 3.9 ohm coils. With points coils from 3.9 to 5 ohms work just fine.
Any coil that has the right ohm specs will work.
There are many aftermarket coils out there that will work. A lot of these coils have a higher output than the stock coils. The stock coils are around 10-12,000 volt output, a lot of the aftermarket ones are 20,000 or more.
This higher output improves starting and running.
They may cost more than the stock coils but they are worth it.
A bit of shopping around will find good coils.
Leo