Man, it's been 10 years but I snagged another XS.

[5twins]

Straight pipes can be difficult to tune for. You may never get it perfect with them. Some small mufflers to add a little back pressure may help.

 

[Primo]

Straight pipes can be difficult to tune for. You may never get it perfect with them. Some small mufflers to add a little back pressure may help.

I've got some "thunder torque" inserts floating around here somewhere from a Harley project, maybe I'll throw those in.

It just kills me, I can run a straight megaphone with no baffles on my green bike and have smooth power delivery but I'm struggling to get it right on this xs.

 

[Primo]

Had a few minutes so I put in my ironhead fork springs. Getting them in was kicking my butt until I remembered I read somewhere that one of these speed ratchet things was the ticket. After 20 minutes of digging and 5 minutes of install they were done.

 

[Primo]

I dropped the main jet down to 140 from 142.5. A little leaner made sense in my mind since the guy who had it before me is at sea level and I am almost 8000 feet. Looking at https://www.engineeringtoolbox.com/air-altitude-density-volume-d_195.html the air density where I live is roughly 75% of what is at sea level. Most of my riding will be between 7500 and 10,000 feet. The midrange stumbling has almost cleared up, just a couple of hiccups. Ran it around the block, about 1 mile dirt road with some decent hills. I need to rework my controls a little and take it on a longer and higher speed run.


Edit: Now I'm curious. The bike was sold to me jetted at 142.5 at sea level. From what I can read for Mikuni that is a diameter of 1.52mm. So the area is 3.1416 x (.76 x .76) = 1.815mm squared . Now I'm at 75% air density so 1.815 x .75 = 1.361mm squared. Looks like a Mikuni 127.5 at 1.36 mm squared would be the closest jet. That seems like a large drop. I wonder if I should drop another size or run what I got.