I instaled a 34mm carb off a Scrambler on my Trail Boss. It doesn't start very easy. Yes I have compression and spark it's a jetting problem. I think I have the correct main jet after lots of plug runs I finally got my plug brown. The pilot jet is what's throwing me off what size pilot jet does the 250 run stock and what size should I replace it with?

Just as a jetting guide, my mods are: AAEN pipe/silencer, trail port, milled head

 

These figures are for the 99 models.

--------------99 trailblazer----------99 scram.
CARB.-----VM 30ss Mikuni-------VM 34ss Mikuni
Main jet------130----------------------230
Pilot jet-------40------------------------35
Jet needle--5DP7-3 ---------------6CEY6-3
Needle jet--0-4 (169)----------------0-6 (480)
Cutaway------2.0------------------------1.5
Air screw---1 turn---------------------1.5 turns
Valve seat----2.5------------------------2.5

These are straightout of my service manual. Hope it helps!

 

Thanks that helped a lot. I'm now running a 30 pilot jet that sounds too small, I'll change to a 40 and start from their.