SR250 Air Fuel Screw Adjustment

In this video we take a look at adjusting the air fuel screw on the Yamaha SR250. We use the custom aftermarket Jadus air fuel screw, but the process is the same with the stock air fuel screw. It is just must easier doing this adjustment on the bike with the thumb screw. The other option is to modify a flat screw driver so that this is possible on the bike.

Jadus Custom Air/Fuel Screw is available here: https://modelikocaferacers.com/gb/jad...

You may notice in the video we needed to screw out the screw more than a half turn to get a reaction from the engine which is not what was mentioned in the video. This will be normal in most cases. The engine should be more reactive on the leaner side of the adjustments. You want to be a half turn away from relaxing the engine from a high idle.

As always, any questions, just shoot!

Cheers!

**UPDATE**

I realise now that this video is not very clear! Sorry about that. The video shows more what to listen for rather than how to actually set the screw. This is the basic goal:

The air fuel screw should be screwed in as far as possible without affecting idle, then backed out a half turn. This is the basic instruction that is mentioned everywhere and has been used for decades. So, start with your screw 4.5 turns out and start turning it in until you notice idle starting to pick up (this video shows what happens and what to listen for), stop there, then back the screw out half a turn. You are set!

Again, any questions let me know,
Cheers