Dyna III installation on an SP 1000

[Sazerac]

I was just gifted an old Dyna III from a friend and looked at the installation instructions but something isn’t lining up. Step 4 says to connect the red lead to the spare connector on the positive side of the left coil, but there is a split white wire that connects to the positive side of both coils.






private image sharing

[guzzisteve]

That's 12V power from the kill switch. If you do not have an extra jumper to plug into on the terminals a 12V source works. You want it switched power so it's not live all the time.

[Sazerac]

Thanks for the fast reply! I’m a bit of a novice, so can you explain what you mean by finding another 12v connection? Can I get one of the male connectors at a parts store and attach it to the coil or do I need to find another location?

[Kiwi_Roy]

I assume yours is a 1980
http://www.thisoldtractor.com/guzzi007/schematics/1980_1000_SP_NT.gif
Notice there is no fuse in the red wire feeding the ignition switch, that could be a problem if you accidentally short out the red wire or any of the others connected to the switch.
With any of the old bikes I have had I added a 40 Amp fuse near the battery just in case it shorts
The diagram shows the coils powered up by terminal 50 on the switch but you could also feed them from fuse 1,2 or 3 (switched circuits)
For simplicity I would keep it from 50.

[Sazerac]

It’s an’83. I found a splitter at the auto parts store and connected it all up. I got the bike to turn over but it runs pretty rough still.

[guzzisteve]

Now you have to time each cyl separately but in sync though the window hole on RH of trans. Watch the air gap, make sure you have plenty.

[moto-uno]

I'd like to assume this bike wasn't sitting for an extended time before doing this ?
I'd like to assume it was running fine before you installed this ?
Have you been able to check the timing with a timing light ?
That's my first line of assumptions before going any further . Peter
 

[Sazerac]

Yes, she was running great but started to backfire on the way back from the rally in Lindale. I took the opportunity to get new pet cocks, fuel lines, rebuild the carbs and new points and condensers. It was running again wonderfully for about 10 miles until one of the condensers crapped out. I swapped them to make sure it was just the one. A local friend found the old dyna while looking for an extra condenser.

I think I’ve got it all statically timed now, but the battery died and is recharging...

[guzzisteve]

Sounds like you got it sorted AND had a good time w/Ken. Lot's of knowledge down there for sure.

[Kiwi_Roy]

Its hard to find good are condensers, I bought a new one for my 72 Eldorado and it gave out a few days later, I had a real struggle to get it back home, I'm back running on the original.

[JukeboxGothic]

https://hmb-guzzi.de/Capacitor-module-all-models-with-2-contact-breakers-T3-LM1-LM-2-etc

If you are having trouble with the quality of capacitors available this may be a solution. I have no experience with therm myself but have found their other products very good.

[wirespokes]

Thirty four euros plus shipping seems a bit much for a couple capacitors. Probably sixty bucks all said and done. How much trouble could it be to pot a couple caps in a little container? Which caps would you recommend, Roy? 

[pressureangle]

The stock charging system, even when 100% which is never, is very marginal for running a Dyna III and headlight at the same time. My '85 was on the battery charger every night, even with a 100 mile round trip to work every day that was 70% 50mph+. In the end, I bought a EuroMotoElectric Enduralast 450 charging system and all my weak electric problems disappeared, as well as weak battery and constant recharging.

[Sazerac]

Update: I had the valves set to .22mm per the book but loosened them up to .30mm and that took care of the back firing. It pops a little when I let off the throttle but nothing bad. I’ll get some new coils ordered to match the Dyna III. Thanks for all y’all’s help!

[moto-uno]

  ^ Popping in the exhaust (on the overrun) is frequently caused by an exhaust leak near the head, something to consider .
Also , an overly lean idle mixture may add to the popping also . Good luck , Peter

[wirespokes]

Also , an overly lean idle mixture may add to the popping also . Good luck , Peter

In that case, not necessarily overly lean. Have you ever listened to stock car racing and how they pop? Those cars are tuned by pros who know what they're doing, and paid well for their efforts. Truth is, perfect tuning will result in that popping and is only eliminated by making the mixture richer.

[moto-uno]

  Good point , But I don't believe they waste much time or effort over tuning out exhaust popping on the over run.
  I'm not sure , but I did mention overly lean idle mixture can cause popping and I'm thinking you confirmed that by mentioning enriching
  the mixture would eliminate that  .  However they were only examples of some of my experiences that corrected those problems
  on occasion .YMMV  , Peter