81 GS450 ds3-3c install wiring question

[Guest]

Attempting to wire up Dyna DS3-3c kit to 1981 gs 450. I know I have to run/reconnect oil pressure switch GY wire in 4 wire pin to harness that old trigger plate plugged into. What about other 3 wires in same 4 wire pin ? My plan is to not reconnect and tape those off as they appear to run to Ignitor which is not in use now. And was going to tape off and not reconnect any wires from 6 wire pin that ignitor used to be plugged into as well. Does this sound correct or am i missing another important connection ? greg

[tom203]

Just tape them off for now- you can get get serious about removing them later! Make sure oil sending unit clears the dyna stuff and still works correctly. Your timing is bound to need a little fiddling so be prepared.

[gs rider]

Thanks for reply Tom, Looks like oil sender wire just clears the dyna plate , i know others have grinded some off the dyna plate not sure why. Timing will be my next challenge. Bought a timing light but never used one.

[gs rider]

Any other tips re the DS3-3c wiring and timing this thing once its wired up?

[tom203]

Basically, you want the timing to be about 10 degrees before top dead center at around 1200 rpm (light will flash on those scribed marks )full advance of 37 degrees should arrive by 3600 rpm or so.heed dyna's tips on how to get both cylinders right.

[gs rider]

hey guys, just got around to installin DYNA DS3-3c on our 81 GS 450. Also did coil relay mod. All connections solid and per GS resource guidelines. Attempting to static time left cylinder first, ignition key on, kill switch on, test light clip to case for ground, tip to white wire/coil connection, holding advance rotor open while slowly turning crank with wrench-- But not getting a light on test light. Am I missing something?

[gs rider]

Re above install - Forgot to mention- checked voltage at coils- 11.67 with a relay? Certainly enough to power a dyna but thought id be reading closer to 12.5 with relay. greg

[posplayr]

Re above install - Forgot to mention- checked voltage at coils- 11.67 with a relay? Certainly enough to power a dyna but thought id be reading closer to 12.5 with relay. greg

read the delta from batt(+) to the coil. That tells you the drop. The coil can not get any higher than the battery.

[gs rider]

read the delta from battery to coil? not sure what delta is? My battery was putting out 12. 6 at pos. terminal and wired directly into relay- so was surprised by the drop to 11.67. still not sure why im not getting static light to light as I rotate crank. ??

[posplayr]

read the delta from battery to coil? not sure what delta is? My battery was putting out 12. 6 at pos. terminal and wired directly into relay- so was surprised by the drop to 11.67. still not sure why im not getting static light to light as I rotate crank. ??

The delta means VOM positive lead to the coil (+) and the VOM ground lead to the battery(+). That will measure the delta or difference voltage and how much you are loosing in supply the coils.

The coil(-) goes up and down as you rotate the engine, not coil(+) (when key is on)

[gs rider]

thank you posplayr- you and others in here have wealth of info for us rookie mechanics. Plan to work on bike again this weekend. Overall the wiring system should be good as I followed lead in this forum and cleaned all connections thruout harness and replaced any suspect loose connections and made sure I had single point ground system. Also, Ive read some use a multimeter for static timing vs a test light. any advantages to that?

[gs rider]

Getting soo close. Got light when static timing left cylinder on a 81 450 with dyna setup. Im holding advance open. Timing marks for left cyl. read lT -obviously dont want that - followed by #s 4 1 2 with a light mark above the 412. Not as deep as the t mark. Is the light line above the #'s 412 the one I align with the casing mark before going to right cylinder timing? I want to start this bike today. greg

[gs rider]

It's running, my temp gas tank was leaking so will reinstall gas tank and then fine tune with timing light. Hopefully everything i did will work as suposed to. New rectifier, dyna and coils., went over entire wiring -connectors, carbs cleaned, new manifolds & orings. thanks for help.