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Discussion Starter #1 (Edited)
Could anyone with a 123 distributor fitted to their Nord engine with otherwise standard components, divulge their recommendations for plug gaps ? i'm using a standard 123, (non programmable), and I tend to get slight plug fouling with standard gaps, particularly on start-up. The engine is around 170hp, running 45 Dellorto's
Mine is all standard, with the 123, and a Lucas gold coil.
I'd appreciate anyone elses experience with experimenting with wider gaps.
Many thanks
steve
 

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Discussion Starter #3
Today I increased the gaps to 0.030" and it starts and runs much better, with less fouling, and a nice browny colour to the tips after a run.
Tomorrow I'm going to experiment with 0.035" and see how that goes,
Steve
 

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The 123 is an inductive discharge ignition which means that current is switched electronically, providing a more fulsome spark than old style points. I run a similar Marelli Plex w/ inductive discharge and have always had good luck with wider plug gaps---.035 to 0.40. For the past few years now I've been running my trusty old Champion N4C's at .035 with excellent results. The wider gap can be easily bridged by the hotter spark provided by the inductive system. Setting your plugs at .035 will probably go a long way toward solving your fouling problem.

I presume your fouling problems are caused by a rich mixture and big cams? If so you might also consider adding an MSD6A capacitive discharge unit to your 123.
 

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Discussion Starter #7
Jim, yes, Piper Magnum 285/2 cams, 45 Dellortos with 38mm chokes. It's great for ultimate power, but not as torquey as I would like around town.
Going to try 40 DCOE Webers with 36mm chokes shortly to see how that affects lower speed driveability.
Willing to sacrifice some top end power for better flexibility.
Don, your plug doesn't look particularly oily. Try the gaps at 0.030", it's made a big difference already to mine.
Steve
 

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123-

Make sure you are using the right coil too. They suggest an impedance range of 1.4 to 3.0 ohms. Recently we had a problem with the rotor lifting inside enough to let the pin fall out leaving the shaft to spin uselessly. This was on a race car mind you but you should all check for this.
 

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[
QUOTE=GTA R;5712849]Jim, yes, Piper Magnum 285/2 cams, 45 Dellortos with 38mm chokes. It's great for ultimate power, but not as torquey as I would like around town.
You should try the 40's. You might also think about a milder cam on the exhaust. There's some discussion on the bb about using milder exhaust cams. We've found success using Centerline's 11.1 cam on the exhaust side with a 12mm Delta A474 cam on the intake. There are a number of other good combinations, however. Using 40's with a milder exhaust cam should give you better low speed performance.

Fred is right about coils. The 123 module is (or was---hopefully that's been fixed with new versions) very sensitive to low impedance coils. You really need a coil with an internal ballast resistor. I don't use a 123 but surely the website has coil recommendations.
 

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Discussion Starter #12
Make sure you are using the right coil too. They suggest an impedance range of 1.4 to 3.0 ohms. Recently we had a problem with the rotor lifting inside enough to let the pin fall out leaving the shaft to spin uselessly. This was on a race car mind you but you should all check for this.
Fred, the Lucas Gold Sports coil DLB105 that I'm using is a 3 ohm coil,
Steve
 
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