Retro Ignition

[genejohnson]

Just for the sake of discussion, would the points say from a 1979 GS850 be a direct replacement for the Signal Generator in a 1980 GS850? I know that other wiring would be involved. I was just wondering how much work would be involved just putting the points where the Signal Generator is. Did they just remove the points plate and install the generator. I am always curious about one thing or another. Gene

[tkent02]

I think it would all fit, if you had the mechanical advance, which a 1980 should have.
Bypass the ignitors, wire straight from the coils to the points.
Don't have an 850 here but I bet it goes.

[Nessism]

The points would not be a direct replacement for the signal generators but as Tom stated, they would be easy to wire up using a few jumper wires.

[mike_of_bbg]

Didn't the points systems use coils with a higher resistance than the electronic ignition systems? Doesn't mean it won't work, but might shorten the life of your points/condenser were you to descend the evolutionary ladder this way.

[salty_monk]

You can fit a 2ohm ballast resistor in front of the 3ohm coils.

[SqDancerLynn1]

It will work. You must use the 79 mechanical advance as it has the cam lobe for the points. Coils will work fine with a 2 ohm ballast resistor. for a dollar or two you can get a 70's mopar ign ballast resistor mount it on the top breather cover with 3/8" spacer (washers) DO the coil relay mod. run one 12v supply line to the resistor, run two wires from the other side. One to each coil 12v line. My 850 still has the points and Dyna green 3 ohm coils been that way 20K miles

[genejohnson]

I realize the changes necessary, I just wondered if you had all the parts from the 79, would it just bolt in? Gene

[genejohnson]

If the points version uses 3 ohm coils, what does the electronic version coil resistance. Gene

[Nessism]

Yes it would bolt in but the wiring is different so you would have to run some wires.

Regarding the coils, the resistance is very similar, not 2 ohms difference. Check the service manual for details but I think the coil resistance difference is less than 1 ohm.

[Steve]

If the points version uses 3 ohm coils, what does the electronic version coil resistance. Gene

Actually, the points version is a nominal 5 ohms. The electronic versions use a nominal 3 ohms.

However, as Nessism suggested, the allowable range for resistance in the two series sort of overlaps.

.

[Nessism]

Actually, the points version is a nominal 5 ohms. The electronic versions use a nominal 3 ohms.

However, as Nessism suggested, the allowable range for resistance in the two series sort of overlaps.

.

According to the factory service manual the '79 850 coils have "Approx. 4 ohms" primary resistance, while the '80 coils have "Approx. 3 - 5 ohms".

The coils are different part numbers which means there is some difference but I don't think the difference is 2 ohms, more like 1 or slightly less even.

[salty_monk]

I don't think you'd have an issue running points with 3 ohm coils.... The points seem to last a long time on these bikes.