Topic: Fine Tuning the 1 commando

[BomberMann650]

I'm pretty sure the stacks themselves arent a problem.  Unlike the cheap pods on cb carbs blocking jets.
The transition on these is really flush.  They were sold specifically for these VM carbs.

Told the owner its at the the more air or less fuel crossroad.  He just wants it to run smooth, admits he probably won't run it as hard as I did, and is as okay with detuning as he is putting a filter on the end of the pods.

Looking through my test ride reports, i noticed a trend of performance improving as air temp dropped.  Which is another indicator that I've given it all the fuel it can drink with the screens in.
If i get in the mood tomorrow I'll take it down the road without the mesh.

For public reference; the jet settings are

Mains 260
Pilot 25
Afr Screw 2-3/4 out (less fuel on a scale of 0-3.5)
Clip position - 2nd notch from the flat top.

Sudco kit 01-250 came with;
Needle type 6DH3
Needle jet 159 P-8
air jet 2.0
Slide cutaway 2.5

Was considering a needle jet change to the leaner P-6, maybe p-4 - to detune around the screen.
Will see what happens sans rock screen in any case.

 

[scottly]

Yes, the stacks appear to be well matched to the carb entrance, but the screens still look to be restrictive to me, especially given their size and location. If they block a certain amount of light, think about how much they block the air as it tries to weave it's way through. The same size mesh, formed into a hemisphere and fit at the mouth of the stack would have a much greater surface area, and the airflow through it would be at a much lower velocity, reducing restriction. If he puts a proper filter over the stacks, no "de-tuning" should be needed.
 
It's normal for performance to go up with lower temps, that's why dynos have weather stations and correction factors to try to level the playing field, so that a test at 100 degrees can be compared with a test at 60 degrees, or a test at sea level vs a test at 4500'. My bike's actual measured power was about 60 HP at 4500', but with correction it was 70 HP, which is what the butt-dyno would have felt at sea level.

[BomberMann650]

Since i have the screens out, I let the bike idle on the work stand for a while.

Observable difference already.  Nortons are famous for their low rpm idle.  700 rippums.
It's happy without the screen. and I haven't changed the afr screw.  My previous idle plug chop was on the mocha side of acceptable.  It started easy and transitioned off the bottom well, so I was happy.
Its probably closer to target afr at idle now.
Gotta refill the fuel tank and give er a rip tomorrow.  Weather should be under 80.

Will have to look see if steel dragon offers a domed screen for their stacks.
Otherwise i'll have to diy something.

[scottly]

Don't change anything until you've tested it without the screens. If you can't get domed screens, reconsider the foam filter socks over the stacks; they may not be pretty, but they will stop more than just rocks from being sucked into the engine. This is just a small amount of the sand I flushed from my Uni foam filters after riding through a desert windstorm on the second relay. If I only had screens, that sand would have gone into the engine.

[BomberMann650]

Learned my lesson about sand in the oregon dunes.  Stopped using k&n filters for offroad and switched to uni.

Thankfully, the Pacific Northwest doesn't have much in the way of dust or sand storms.  The rain certainly keeps that to a minimum!  And unlike the flyover states, most all of the farm roads are paved.

The Nortons owner and his ol lady are masters with a needle and thread.  Making foam filters
 slip covers wouldn't be hard for them.  I just have to get a piece of material for them.

[BomberMann650]

Worst.  Test ride.  Ever

Ran great without the screens.

Then the center stand spring let go.
Then the primary cover came loose.
And an engine bolt tried to yeet itself into the ditch.

Plus, timing wandered off the mark....again

[grcamna2]

Learned my lesson about sand in the oregon dunes.  Stopped using k&n filters for offroad and switched to uni.

Thankfully, the Pacific Northwest doesn't have much in the way of dust or sand storms.  The rain certainly keeps that to a minimum!  And unlike the flyover states, most all of the farm roads are paved.

The Nortons owner and his ol lady are masters with a needle and thread.  Making foam filters
 slip covers wouldn't be hard for them.  I just have to get a piece of material for them.

I like the UNI light green foam fine filter material.

[BomberMann650]

Ordered some outerwears socks, those will do well enough.

Still gonna take the needle jet down a step. 
Weather was 72 today.  While i was able to cruise and pull in top gear.  I won't be able to ensure performance on a 90° day for a while.

Parts falling off sucks.
Unreliable timing unit sucks.
Calling for a tow every other day sucks.

[BomberMann650]

Those paint marks used to be in a straight line.

So the problem isn't in the optical pickup or coil.  It's the damn encoder wheel moving around on all the polished surfaces.

I'll give it one last chance before it goes in the bin.

With more star lock washers this time.

[Medyo Bastos]

I think I have an encoder wheel under my bed


Sent from my iPhone using Tapatalk

[scottly]

I think I have an encoder wheel under my bed


Sent from my iPhone using Tapatalk

That's a good place for it.

[BomberMann650]

The Norton earned the officers choice plaque at the hometown amca meet!
It gets looks everywhere it goes.  Even on a trailer.
The bikes on display were well put together.  Lots of European models in the lineup.

That starter flywheel was still broken and the replacement hadn't arrived before the show.
Just got it all apart tonight with a shop made puller and an impact wrench.  Thankfully the damage was contained.

It did get some socks for the staxxx and a step down in the needle jet size.  A little fix in the rear brake drum.

There's also a new ignition module coming in the mail.  The powerarc left me stranded three times so its outta here!

Though i think i could still fix the encoder wheel with some reengineered parts.  i.e. drive dogs and match taper cam timing spacer.  But its hard to trust it anymore.

[BomberMann650]

Tri-spark ignition arrived and of course the instructions leave some questions unanswered.
How can 3 wires can be so dang complicated?

Wanting to keep the coil that came with the power arc.  Old britts provided a nice coil, set up with three connections.  Pos, Neg, and Trigger. 
The tri-spark provides three wires.  Which I also assume is pos neg and trigger.
But they have the module grounded to the engine,. The remaining not red hot wire is illustrated going to the coil ground connector.  As their expectation is consumers would be using coils with two pin (+/-) connections.

I emailed tri-spark (@email.dotcom.AUSTRALIA!) with hope their tech department gets back to me.  But if anyone here can shine a proverbial light i'd appreciate it.

Also r.i.p advanced map curves 😢

[RAFster122s]

The white orange wire from power arc module goes to your trigger on the coil...
What is so difficult?
The red wire goes to positive and ground is black...
Not sure why you are confused by this...looks very straightforward...

[BomberMann650]

Power-arc is being removed.

Tri spark doesn't exactly specify the function with their color code.
Just wanting some certainty that hooking this up in an "off book" manner won't release the factory provided smoke.

[simon#42]

i have fitted a couple of tri spark ignitions with good results . i have only ever used a standard two terminal coil .

[BomberMann650]

i have fitted a couple of tri spark ignitions with good results . i have only ever used a standard two terminal coil .

I guess i could use the test button to find out if the old britts coil will light off with only pos and neg attached.

It's tempting to pick up one of their fire box systems for the sohc4.  More tuneable than the dyna2k but more expensive as a total ignition package.

[scottly]

Wanting to keep the coil that came with the power arc.

Why?? Who knows what POS coil came with the POS power arc, or WTF a "trigger" connection on the coil is for? What is the primary resistance? What coil does the new ignition specify? Are you willing to let the smoke out?? I'd rather try a stock 5ohm CB coil.

[BomberMann650]

Wanting to keep the coil that came with the power arc.

Why?? Who knows what POS coil came with the POS power arc, or WTF a "trigger" connection on the coil is for? What is the primary resistance? What coil does the new ignition specify? Are you willing to let the smoke out?? I'd rather try a stock 5ohm CB coil.

PowerArc hate aside.  The problem with this p/a wasn't the electronics.  The norton system was developed by a much beloved member of the Norton community.  With some happy (and turbo charged) customers.  Seeing as I can't be arsed to engineer another solution for the encoder slippage - the timing pickup is being respectfully retired.

Things are already wired and fit so retaining the coil makes sense.
Simply trying to keep the build from running further over budget and behind schedule.

Tri-spark specifies 3 or 5 ohm coil if not using the oem Lucas canisters.  I'd expect the old britts single coil to be in that range.
Their module apparently carries the ground for the canister coil.  As their diagram shows the module grounded to engine, and coils grounded to the module.
As for the old britts coil, their diagram has both coil and pickup grounded to (in my case) chassis - with the pink and white wires carrying a signal to the trigger input of the coil.
Would have to dig into powerarc tech docs to uncover what sort of signal those wires carried.

[scottly]

Tri-spark specifies 3 or 5 ohm coil if not using the oem Lucas canisters.  I'd expect the old britts single coil to be in that range.
Why would you assume the "old britt's" coil that was custom designed for a PA to be the same? The PA required low impedance/low resistance coils in order to do what the system was claimed to do. Remember the part about the reduced spark-plug gap?
What is the resistance between the +12v terminal and the "trigger" terminal, and also the resistance between those terminals and the ground terminal? 

Their module apparently carries the ground for the canister coil.  As their diagram shows the module grounded to engine, and coils grounded to the module.

The Tri spark module has three connections: switched 12V, ground at the mounting post, and the black/white wire to the negative terminal of a standard coil. The positive terminal of the coil is also connected to switched 12V. 

[BomberMann650]

Only assumed the coils ohm rating cause i hadn't dug out the DMM to test it yet.
Got an email from tri-spark and they weren't certain it would work either.

[Stev-o]

The Norton earned the officers choice plaque at the hometown amca meet!

Congrats!

[BomberMann650]

The Norton earned the officers choice plaque at the hometown amca meet!

Congrats!

Thanks.

The competition was - Fierce ... To say the least.

[BomberMann650]

After tri-spark informed me the old britts coil was likely incompatible - the part got replaced.
The fine gent at CnW supplied a coil kit (harley component he runs on his tri-spark built nortons)
Then I spent a couple hours making a simple bracket and dressing up the wiring.

Verified timing with a strobe and may have to tinker with the fueling a little more.  Hopefully now with reliable stop-starts.

[BomberMann650]

The Norton made a successful test ride out to a popular roadside attraction.

It's now off to its forever home.