What size jets should I use on my Yamaha fzr400 1WG racebike if I remove the air filter and/or airbox.?

The bike has a race pipe (EXUP valve removed) and is currently running on Avgas but is running very lean even with airbox and filter.
Main jets are 92.5, needle jets on middle setting.
The engine is otherwise standard early (one of the black engines) 1WG.

Answers:
Make sure you use some sort of filter, K&N or something like that if you're intent, Dynojet do kits specifically tailored to run with these and race pipes, you'll probably need a stage 3 dynojet kit, looks like you are anyway but keep an eye on the fuel/air mixture for a bit after making any alterations
Run 110's on cylinders 2&3 and 107.5 on 1 and 4.
Didn't you get a set up manual with the jet kit?
Try DYNOJET or FACTORY for specific details, but remember your needs are different depending on air density and temperature!

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