I have only tried the stock exhaust that came with my bike and the one I bought on ebay, there very well could be an ebay/amazon/aliexpress/you-name-it exhaust system that will work with the 190. I would go and ask the 190 swap facebook group, but I sincerely dislike facebook altogether and once they asked me to verify myself with an ID photo, I gave up on my account.
If I had the funds to test out the fitment of many different exhaust systems so you or anyone else wouldn't have to, I would. I wish I could. I am a humble being with a humble occupation, and I cannot do that. If I tally up the cost of everything I've bought on this project so far including the bike itself (granted some of it isn't needed), it comes very close to a new genuine honda grom. All I can do is tell you what to look out for, what I've learned with my exhaust, what has worked, and what hasn't.
On to slightly more upbeat news, I made a fender eliminator/tail tidy/moto-thong-be-gone! I didn't get to the hardware store today, but I did the next best thing; rummaging around all of my junk boxes, tool boxes, tool chests, spare parts boxes, scrap metal boxes, and underwear drawer for useful scraps of metal stock, bolts, nuts, shiny things, etc. I found 2x large 90 degree braces probably meant for holding up shelves, 2x small braces, hardware and mounting brackets for bicycle reflectors, lots of misc. hardware, and a one-way air valve that used to be on my scooter, and probably some other stuff I'm forgetting.
There are four screws holding the plastic cover over the metal frame inside the stock tail extension, remove those and the four bolts underneath the seat holding the tail extension frame in place and the tail extension will come right off. Be careful not to yank on the wires for the turn signals and the license plate light. The turn signals come out after you remove the nut securing them in place. The license plate light is behind about 2 or three pieces of plastic just screwed into place.
I bolted the two larger braces into the two rear former-tail-extension mounting holes. I had to drill two new 1/4" holes in the folded metal piece that holds the red reflectors. I also had to (eep) drill two new holes in my license plate so I could use the two same mounting bolts for everything. The holes in no way obscure the license numbers or the reg sticker, they are just about 3/8" inward from the "standard" holes. Where the reflectors used to be held, I drilled out the holes to a little over 3/8" and put the turn signals in there. I mounted the red reflectors on the two smaller braces, which I mounted to the bottom two holes on the license plate.
I wanted to keep the one red reflector that faced straight backward, so I bent one of the bicycle reflector mounts into an "L" shape and bolted one end to an area on the undertail plastics that looks like it was meant to hold a bolt or a screw, and attached the reflector to the other end, facing backward, a little behind the license plate.
For less than about $10 worth of scrap pieces from previous projects, I think that looks pretty good. I will eventually paint the braces black.
I got the silicone out again and REALLY sealed the MAP/IAT/TPS box, as well as went around the injector housing. I'm not sure exactly where the air leak is, but it needs to be gone. I wish I could blow some smoke through the throttle body or submerge it in water to see where the air is coming out, but I don't think that little black box would appreciate being smoked out or dunked in water. I could just take the black box off and try testing the TB without it, but that would screw up the TPS-zero and TPS-100% readings in the tuning software, as well as in the firmware on the ECU. I know how to fix and correct that, but I'm just going to leave well enough alone for now.
I connected the crankcase breather tube to the engine and added a one-way valve to the end of it so the air in the crankcase will always be at least at atmospheric pressure, if not lower, so oil won't get pushed out of any seals when there's a lot of blow-by. I routed the outlet tube from the one-way valve down toward the left side of the rear swing arm, out of the path of the rear tire. If any oil or oily-gasses escape and make it all the way out to there, they will fall onto either the ground or onto the chain. I don't think motor oil can hurt a motorcycle chain. The white spiral wire wrap is so the tubing does't kink at that tight 180 turn.
I found an old but still in very good condition small section of very large gauge wire I am going to use to ground from the engine to the frame. Right now I am relying on the mechanical connection of the engine's mounting holes and the frame's mounting tabs for an electrical connection between them. I works for now, but I don't want to rely on it long term. I'll probably bolt it up to the frame where I took a picture of it with a bolt on the engine right next to an unoccupied bolt hole in the frame, unless I can find a better place.
I also de-glazed my front brake rotor with a scotch-brite pad. I usually rely on engine braking for the first half of my braking force, and then use the front and rear brakes for whatever speed is left thereafter. So, the front and rear brakes get only light to moderate use, which ended up polishing the rotor instead of bedding the pads and rotor together. No biggie, neither the rotor or the pads are ruined if this happens, just scuff up the rotor with fine-grit (about 200 or more) sandpaper or a scotch-brite pad until the glaze is gone. You will have to press rather hard while scrubbing.
Things done: (some not talked about)
- Fender eliminator
- Zip-tie fuel pump and starter solenoid
- Reinforce battery tray plastics with zip ties
- Add reflective tape
- Seal MAP/IAT/TPS box
- Level fork height
- Add one-way valve to crankcase breather
- Forget where you put that screwdriver you just had in your hand not 3 seconds ago