Apologies for waiting almost a month between updates, but I've hit a mental project exhaustion tipping point. Details at the bottom of the post (kinda whiny/needed-to-vent/oh-man-I-need-a-therapist)
Post 1/2
Ever since my bike was delivered the throttle tube was quite loose on the handlebars. Something like 1-2mm of play between the ID of the tube and the OD of the bars. By comparison the throttle tube on my scooter is quite snug. I decided removing the slop from the tube is worth while since it will give me finer throttle control.
I removed all the bolts holding the right handlebar control cluster together and disconnected the throttle tube from the throttle cable. I measured the OD of the handlebars and the ID of the throttle tube to see which is the culprit... The throttle tube! It was about 2.4mm diameter too big. I decided to wrap the handlebars with a very thin, slippery fabric to fill the void. The best thing I could find was a synthetic almost tyvek-like fabric. I wrapped the handlebars and trimmed off bit by bit until the throttle tube fit on snugly while still being able to snap back to closed if I let go of the throttle tube.
As the bike is now, the clutch handle has a very uneven feel. The friction zone of the clutch is RIGHT where you start to feel "real" tension on the handle, not just the spring tension holding the cable taught. So from the point where the clutch is not being held in, up to right before you are in the friction zone is just spring tension, but as soon as you enter the friction zone all the way to the clutch handle being completely pulled in, there is tension from the clutch pressure plate springs as well as the clutch return spring.
It has been difficult to develop muscle memory for the clutch friction zone with the tension changing based on the distance moved. I want to install an additional return spring for the clutch to give the handle a more consistent feel. The extra spring I have from the exhaust is too small and I don't want to go out to the hardware store and pay $5 for a single spring. I'll need to fabricate something at a later date.
My whole body misses having a balance shaft.
The last couple times I was out on a ride, I heard some metal rattling while riding. It wasn't like a too-lean engine knock, it wasn't the valves (though they did seem a little louder than normal), and it didn't change with engine speed, but with road speed and condition. Something made of metal is loose or something loose it hitting something metal. Quite possibly one of the unused wiring harness connectors flapping around in the breeze and jamming out to the good vibrations from the engine and the wheels. I still have yet to properly secure the wiring harness as much as I would like it to be. For another time.
I checked the valve clearances again since the valves seemed just a wee bit too loud. The intake had gotten tighter than .003" and the exhaust was at .005". I adjusted both to a .004" go/.005" no go clearance. That seemed to work, though there was little difference is noise of the valve train.
The baffle I made in the previous post did work at quieting down the exhaust slightly. Subjectively, it went from an 8 (0-10; quiet to loud) to a 7 or 7.5. Audible, noticeable, measurable difference, but not quite enough for me. Also, I could tell it was one of the more restrictive ways of quieting exhaust; 3/4 to WOT was in the 10 AFR range without jet changes.
Yep I did it again. Another thing to try and quiet down the exhaust. I'm obsessed at this point. It is either this or (gulp) back to the restrictive as hell OEM exhaust and goodbye wideband.
I first laid eyes on the muffler while searching, oddly enough, how mufflers are manufactured and difference quieting techniques. I found a link to a muffler that just looked like any ol'
pit bike muffler. However this one was marketed as "quiet". I had never seen an after market muffler marketed as quiet. Most try and push that they are loud and brash. Tbolt's website doesn't provide a picture of the inside of the muffler or of the silencer after it has been removed. I needed to see how the silencer was built to determine, from pictures only, if the muffler would be quieter than the one I have with the baffle installed.
I searched ebay, amazon, and aliexpress for "pit bike muffler" and scrolled through all the listings my brain could handle and clicked on the ones that had a similar looking exhaust. Finally I found
a listing that showed the silencer after it was taken out of the muffler. Perforated tube with end rounded off and closed, roughly 30% open area, 1/2 covered by a fiberglass muffler packing sheet. In my mind, that silencer would make that muffler quieter than what I have now.
OK, I've decided to buy the muffler as a last-ditch attempt to quiet the exhaust down to a reasonable level and keep my neighbors friendly, or at least tolerant and non-hostile. I can be pretty sure that any listing for this specific type and look of muffler will have the silencer made as shown in the pics from the above link, so I searched the three sites again and found that I would have to wait for at least a few weeks to get one; no US sellers had them in stock. So it would have to come from overseas; the place where all of our electronics are made, the place where they drink a lot of tea, or the place where everything is trying to kill you (affectionately, China, UK, and Australia). I chose the slow boat from china; no rush, save money.
Also, a plus for this particular muffler (for me at least) is that the ID of the exhaust inlet is 38mm. Most chinese after market mufflers are 51mm and come with a conical 38-51mm weld-on adapter. The OD of the exhaust pipe I have is 36mm. I thought I would need (and bought) slip rings that go on exhaust pipes to effectively increase their OD, but I didn't need them. Just some sealant around the pipe before final assembly worked fine.
14 business days later...
It's smaller than I thought it would be.
The silencer looks just like it did in the listings I found. Cool, I got the muffler I wanted.
Removing the old exhaust was quite easy thanks mostly to the outside of the exhaust being coating in a chrome like plating. That made twisting off the old muffler and scraping the old sealant off quite easy. Luckily the mounting hardware I made for the old exhaust would 90% work with the new muffler. I had to mount the hanger supplied with the muffler backwards so the part that is supposed to be facing outward and have either a nut or a bolt in it, would be facing inward, pressed against the muffler bracket I made. Not the prettiest solution, but it works. I need to put 2 or 3 washers between the space in the clamp halves so I can torque down the mounting bracket's bolt without worrying about snapping the clamp.The new muffler fit perfectly and stays in place even without springs thanks to the muffler clamp.
With a cold engine and full choke, I started the bike with the new muffler. Yes! this is the sound level I wanted! Loud with a brap under load but calm and civil while cruising. A bit louder than oem with more pop and no buzz or raspy sound. Yeah, trying to explain changes in sound with words is difficult.
After the inaugural run with the new muffler I noticed a few wisps of exhaust packing being pushed out of the muffler. It seems as through this muffler wasn't made with any or enough sealant between the end cap and the main muffler part (the part that is that weird brown/slightly purple/burned bronze color). I have more than enough packing material to repack this muffler if need be. For the time being, I am not worried about tiny bits of the packing material making an escape, unless somehow the whole of the material came out in one giant moto-snot-rocket. Then I would just laugh.