So I built out my 1999 FLHR from an 88ci to a 103ci and I currently have the stock jets in my Mikuni HSR42. Running a S&S 551 torque cam, stock 2015 103ci heads, Wiseco 9.6:1 pistons, V&H Pro Pipe 2 into 1, and Cycle Visions high-flow air cleaner. Trying to get around buying the full 2-of-everything Mikuni jet kit and I'm wondering if anyone has a good starting point on jet sizes. This project has already cost me WAY more than I can stomach at the moment, and I wanna make it through the riding season with a good jet setup until I can buy the kit and get her Dyno'd this winter. Any ideas?

 

25-27.5 pilot.
160-165 main.

 

Ahh ****, wish I saw this before I bought my set. I went with a 25 pilot, 96 needle, and 172.5 main. I'll start with that and if I have top-end issues, I'll try the 165. Thanks for your input!

 

Base line suggestion, not gospel.
Scott

 

Confirming that 25 pilot, 96 needle, and 172.5 main work fantastic! Easy idle, great top end and acceleration.

 

 

Update: She's running rich as hell, flying through spark plugs. Dropped to a 165 for a few months. Same. Dropping to a 162.5 now.

 

If killing the plugs with a 165 main, then make a good move......go to a 160.
Scott