I drove home today with the intent of finally getting the throttle-body balance taken care of. The bike was already running a lot smoother since I did the valves, but I wanted to get one of the last things done.

By the time I got the bike home, it was up to operating temperature and it should be a few minutes to get hook up the TwinMax (to the right) up and fiddle with things to get everything perfect.

Up until I realized the TwinMax wasn’t working – the knob to zero out the reading wasn’t doing anything. Occasionally it would work for a moment or two, but that quickly wore off. I didn’t feel like buying a new one for $100 either.

How to open it up… the underside has four rubber feet. Pulling those off revealed some screws. Unscrewing those got the two halves parted. (If you do this be careful; the pressure sensors is attached to the front half, and the rubber hoses leading to it are on the back half. Ripping it open would rip it apart.

After carefully taking the hoses off I checked out the broken part: a 100K ohm potentiometer.

We were heading to Chipotle anyway and there’s a Radio Shack in the same plaza so I picked up a new resistor from them before the burrito. It was a very different form factor, but I really wanted it to work.

Getting home I realized I have no clue where my desoldering braid is. Back to the Shack.

After a bit of futzing I took off the old part and with the help of some spare Cat5 I attacked for some wire I hooked up the new potentiometer. It worked!

With a bit more finessing I even got it mounted on the case such that it could close.

The upshot of all this is that it works! It just looks really strange.

In the picture above the small part is the old device and the new one supplies the really long shaft that’s coming out the side of the Twinmax.; I made a Frankenstein! At some point I’ll just chop it down and add a better knob. I’m tired now though.

I’ll take saving $100 any time!