I bought a 2006 YZ250, have ridden it 5 times.  It needs some tuning, but I am not sure I'm keeping it so don't want to spend much on it.

Has fmf gnarly expansion chamber and turbine core silencer.

I ride about 1000 feet above sea level.

I'm going to clean the carb and check the jetting.  What is a good jetting for me?  85 main jet?

Also check the reeds.  Is there a big difference between getting aftermarket reed cage and reeds or just getting a cheap aftermarket set of reeds that fit the stock cage ie.  Boyesen Power Reeds?

The other things I'm going to do is permatex all the joints in the exhaust system and a compression test.   It was 220psi 5 rides ago so I'm guessing itll be fine.  Its bogging a bit but I'm thinking its carb and definitely exhaust joint related.  

Let me know if I'm overlooking anything that could make the bike run crisper and more bottom end without throwing much money on parts

Start with a 45 pilot jet

tesearch suzuki needles 

google spanky’s jetting guide for correct airscrew setting and how to test all the tuning circuits in the carb

It's winter/cold so bogging could be a lean bog. Report back on what jets you have. If you were running 32:1, an easy switch is to run a batch of 50:1. If the bike runs better, you've probably got to step up one or two pilot jet sizes. 

Boyesen reeds for stock cage is good. Some prefer them over the full cages.

I'd get the carbonfibre version. 

I have a 06 yz250. At sea level the stock jetting is pretty good (50 pilot, needle in second clip from top and 178 main)

I have v force reeds, the PO installed them otherwise I'd have stock ones.

I have the stock expansion chamber with a fmf powercore silencer also installed by the PO otherwise I'd have the stock silencer.

I'd clean and repack the turbine core, it could be getting plugged up.

Edited by biglake

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