BD125-8 ZS190 swap and EFI conversion

glavey · 01-29-2019, 01:22 AM

I think I found a very good mounting location for the fuel pump. I took the starter solenoid off the two mounting tabs and out of the rubber holder, cut the bottom flange off of the rubber holder and slid it over the fuel pump. Nearly a perfect fit. I moved the starter solenoid to the tab above the rear brake fluid reservoir. I had a spare rubber holder from the extras that came with the 190. The pump is a little tight between the tabs on the frame, but that is better than too loose. I'm still going to secure it with some zip ties.

I drilled and tapped two new holes in the 190 manifold for the TB mounting points. I wanted to use a metric thread so I could keep almost all things of the hardware on the bike metric, but the closest I had was a 1/4-20 so I went with that. The holes and threads are a wee bit off-center, but still very usable. Even if they end up too crooked or I strip the threads, I can just use a nut on one side.

I ordered the intake clocking flange from steady garage. It seems almost mandatory to have some way to either raise and/or rotate the intake if you want to use the flange TB from aliexpress. You might be able to squeeze the clamp TB in, but it will be difficult. I still might attempt to put the injector directly into the manifold on the flat spot...

I tested some of the wiring on the aliexpress harness - the heater circuit for the oxygen sensor is directly connected to battery voltage and ground, no control from the ECU. The fuel pump is connected to battery voltage and switched to ground via the ECU. This means I can wire two relays to both turn on when the fuel pump is supposed to run, while still having two separate and fused circuits. So whenever the fuel pump is running, the o2 sensor will have its heater on. I can turn off/disable the o2 heater if I find that it is drawing too much current or the exhaust is heating the sensor enough/too much. I might wire the CDI to turn off whenever the fuel pump is off as well, it seems safe to disable the ignition when it isn't needed.