Main Jet Size For Hyde Togas

Google Jenks Bolts Tuning Guide and download it. With just TORs you are looking at 120 mains, the standard 40 pilot jets and the air screw about 2.75 turns out.

 

I just installed the Normal Hyde peashooters and the bell mouth intake. NH recommends 128 mains and no idle jet or screw work, other than stock. Installed same and seems to work well. If you are just doing the silencers, something smaller than the 128 should do. I would buy a few sizes (they are cheap) along with the stainless float bowl screws. Start with 120, and see how it goes. The socket screws will make it easy to change jets.

 

My bike came to me with Uni-flow air filter and Norman Hyde Togas and an extensive history detailing what was needed to get her running just right. Initially she was fitted with 120 main jets but those were increased to 122's and, the history says that pilot jets were increased to 42's to solve a rough spot at 2000 rpm. The bike is definitely a sweet runner now.

The history also says that my machine is fitted with Thruxton needles which, according to the Jenks tuning guide shouldn't require a 42 pilot jet so, perhaps you will be fine with the standard 40's.