Sportster Scrambler Build

[BurlyBrand]

OK guys, we know what the ignition module is and does. Question here is the box that is inline on the tailight/signal harness.

pablo83 - Good advice on removal of the ignition module before welding.

itsteeravfool - see above

tattoo2303 - Not a flasher relay as lights flash without it.

As the engine increases in RPM the spark timing needs to become more advanced. On old bikes you had to set the timing manually (usually by turning the left grip sort of like the throttle). Then they came out with mechanical timing advance where spinning weights would move the points system and advance the spark. Now they use an ECM where a magnet on the crank shaft sends a signal to that box. The box calculates how fast the engine is spinning and sends juice to the coil when it thinks the spark should fire. With an ECM there are a lot fewer moving parts than with a points system and mechanical advance so they tend o be more reliable. I usually unplug the ECM before welding on the bike so I don't fry it.

[BurlyBrand]

Yeh, that's a great looking build!

As the engine increases in RPM the spark timing needs to become more advanced. On old bikes you had to set the timing manually (usually by turning the left grip sort of like the throttle). Then they came out with mechanical timing advance where spinning weights would move the points system and advance the spark. Now they use an ECM where a magnet on the crank shaft sends a signal to that box. The box calculates how fast the engine is spinning and sends juice to the coil when it thinks the spark should fire. With an ECM there are a lot fewer moving parts than with a points system and mechanical advance so they tend to be more reliable. I usually unplug the ECM before welding on the bike so I don't fry it.

I look forward to your build. Last winter I built a Japanese tracker with scrambler style pipes:


I've gotten lots of good feedback about the pipes. I'd like to do something similar on a magneto ironhead soon.

[pablo83]

OK guys, we know what the ignition module is and does. Question here is the box that is inline on the tailight/signal harness.

Blinker relay?

[EDIT] Wait, does it have like 12 wires going into it? That's some kind of light control module, it controls blinker timing and automatic cancelation. It shuts off the headlight while starting the engine, etc. I'm really not sure why it's all necessary. I think even the horn plugs into it. No idea why. Do the hi beams flash when you hit the horn???

[2nd EDIT] Sorry, the horn doesn't plug into it, but I still have no idea why another black box was added just for the lights.

[tattoo2303]

my next guess would be starter relay than, but i could have sworn they had a little tab to mount it molded to it

*edit i thought for sure the colors of those wires going to it are turn signal marker wires, do the left and right turn signals work (flash) independantly with this unplugged still??

any better pics?? the underside and the side with the schematic and/or part #s would help

[BurlyBrand]

We eliminated it and everything works fine.

[pablo83]

We eliminated it and everything works fine.

how many wires does it have going into it and what colors are they?

[BurlyBrand]

Sportster Scrambler Build

Rear hoop shaped up nicely. Ribbed fender is just the right width (we guessed and got lucky) and some tabs from McFadden Dale should hold things together.





Found an NOS Six-Pack rack from an ATC on Ebay. Fell in love. For sure this will end up on the build.




Some simple brackets and a bit of rubber isolation to keep weight of ign module that will be mounted forward of this from causing the fender to crack.








Next project is a seat. Plan is to do a completely flat Scrambler/Brat style seat. The Sportster's ass low chassis really does not want a flat seat, but tall shocks should open up the rear end and allows us to break the humpy seat tradition of the XL.





Our marketing guys first shot at forming metal. Probably more blacksmithing than anything else, but we're not going to over-think a seat pan. Hump should wrap around the fender and front of seat will hinge off of the rear tank mount. We're stoked on the results.







Found these little buddies on the Kuryakyn site. Run/Turn/Brake and insanely bright. Wacky fine metric thread forced a ghetto fab recessed nut sort of mounting, but the results look pretty sorted.

http://www.kuryakyn.com/Products/4124/Razor-Eyes

Some grinder love and a couple coats of rattle can glossy black and it looks like it came that way (or at least we think so...)

[brooklynbomber]

YES!!! Can you post a current side profile shot? Want to take this in in full glance. Way to go gents.

[BurlyBrand]

We'll get there. Couple of new parts on it that we can't share yet. Play along and we'll make it worth your while.

YES!!! Can you post a current side profile shot? Want to take this in in full glance. Way to go gents.

[pablo83]

well shit, yall are moving right along.

[punkrod]

It looks like a HD turn signal modulator to make the turn signals run as brake lights. p/n 69461-06A

[BurlyBrand]

Ran into some challenges. Running some taller shocks to level out the chassis and glom onto the Scrambler look. Overly complex HD rear brake linkage is now hitting the belt.





One of our crew drew this up over lunch and we hit a local board shop on the way back to the office. "Can we get a wheel and a set of your best bearings?" Countermonkey: "Ummm.. we only sell them in 4s and the bearings in 8s..." Yes, countermonkey, we know how skateboards work. What do you have laying around? That must have been the right question as we exited with a perfect wheel and some shitty bearings, gratis. Tensioner pivots on bushing and we'll need to create an inner bearing spacer to keep the wheel from getting wonky at speed.




Back to McFaddenDale for real bearings. Bummer of a brand name.

[BurlyBrand]

It does look similar, but this bike predates the Nightster by a year and ran traditional taillight and signals. We've eliminated it for now and all systems function correctly.

The mystery deepens!

It looks like a HD turn signal modulator to make the turn signals run as brake lights. p/n 69461-06A

[pablo83]

What shocks are you using? Do you know how much travel the rear wheel will have?

I tried to catch a little air on my GR and the oil pan really didn't like it. I'd like to have a bit more travel on my next tracker....and a skid plate

[BurlyBrand]

Shocks are part of the secret new stuff program and they should stroke between 4 and 5 inches. Look for a release on them in January. Plan is a low buck tall shock for the Sporty that will tolerate some abuse. Building them with the Cafe, Scrambler and "F-you, I don't want my bike lowered" bikes in mind.

That's an awesome/tragic pic. We're working on a skid plate to avoid just such an issue.

What shocks are you using? Do you know how much travel the rear wheel will have?