see also: Speedohealer

By Slyboy May2004

Today I installed a Yellow Box for the first time and thought I'd share my experience.

For the uninitiated these correct your speedo for either factory inaccuracy or as in my case to correct your speedo readings after changing the bike's gearing. I decided I wanted to put the Yellow Box under the rear seat for easy access so that I can adjust it if necessary.

First step is to take off the black side panels and front and rear seats.

Then undo the Allen key bolt holding on the speedo sensor and carefully pull the cable back through the frame to the connector. Then undo the connector so that you can work on the sensor wire away from the bike.

Then strip the wires on the speedo sensor as per the instructions making sure you stagger the two wires which are stripped either side of the cut wire.

Then solder the wires from the Yellow Box, again as per the instructions. Once these have been soldered, tape up each wire with insulating tape (or use heat shrink insulation).

NB..... the harness with the Yellow Box actually has a grey wire instead of a green one as described in the instructions.

For a copy of the instructions on-line see the following link:

www.blackrobotics.com/yb_inst.htm
 

Now its time to re-install the sensor and Yellow Box wiring harness back onto the bike. Before I did that, I fully insulated the entire Yellow Box wiring harness using insulating tape. I did this because the instructions say that you should not run the harness anywhere where there is heat, however you must run it past the rear cylinder head no matter which route you take.

The I drilled two holes in the Yellow Box itself in order to fix it using cable ties to the frame (red dots in pic below)

Then connect the speedo sensor to the connector block and carefully re-route the sensor cable back to its original location, taking care to keep it tucked behind the clutch hydraulic line so that it avoids the heat from the engine. I actually cable tied it to one of the main engine mounting points to hold it away from the engine. Fix the sensor using the Allen key bolt. Now its time to route the Yellr Box harness wire to under the seat.

I ran it behind the frame along the route of the existing cable (see pic below) and fixed it with cable ties.

Then before you fix the Yellow Box I suggest you alter the little dill switches to the ratio you think it needs to be changed to. I used the calculator on the speed healer web site to estimate the percentage change I needed. See link below:

www.speedohealer.com/eng/adjust.htm

I changed mine to 15% (I have one teeth less on the front sprocket and two extra on the rear)

Next fix the Yellow Box into position on the rear sub frame using cable ties and connect the harness to it using the plug. I put it on the left spar as I intend to fit a Scottoiler to the other rear sub frame rail.

One thing I forgot to say on my last post is that before you start routing and fixing the main Yellow Box harness you should plug it in, turn the ignition on and make sure you get the light flashing on the box. Then route it to where you want the box.

Hey voila - one Yellow Box fitted. It took me about 2 hours, but I was being ultra cautious and was taking pictures as I went.

I took the bike for a spin and did a rough check of the speed against my brother's bikes speedo and it was pretty much spot on. I intend to check it against the distance markers on the motorway next to see how accurate it really is. (You clear your milometer at the fist post, drive 5 miles and check what your speedo milometer reads. Divide your speedo reading by the actual distance and this gives you the ratio you need to amend the Yellow box by).

Comments:

jrl305: I have a naked and I put mine under the back seat. I used a GPS and stopped every so often to adjust it. I think you're looking at around 18% or more before it's spot on if you went down 1 tooth in the front and up 2 in the back. I went 1 down in the front and it worked out to be 14.5%. I don't know if the "S" model has the same area under the back seat as the "naked" but it sure is easier to get to when in the tuning phase. Once it's set, you can pretty much forget it. Remember, if you're looking at another bike speedo, it's off too. The stock SV is off by 9%. Also, the ODO doesn't end up the same as the speedo for some reason. My speedo is spot on at 75mph and now the ODO reads a little behind. That's ok 'cause the miles don't rack up as quick. For some strange reason, the ODO is pretty close from the factory.

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