jetting help at elevation

[squirrel]

Newbie here just ordered a tm39 pro from randy at odyssey salvage had the motor ported and head recut installed power jet on carb and my problem is it almost fouls a plug idleing he sent me 370-440 mains and I am already down to the 370 and the needle dropped as low as it will go and a 45 pilot. anyopne else run this setup at any elevation. I am at 8500' and go up to 10 plus. Thanks

[hoodlum]

Newbie here just ordered a tm39 pro from randy at odyssey salvage had the motor ported and head recut installed power jet on carb and my problem is it almost fouls a plug idleing he sent me 370-440 mains and I am already down to the 370 and the needle dropped as low as it will go and a 45 pilot. anyopne else run this setup at any elevation. I am at 8500' and go up to 10 plus. Thanks

What air intake system are you using? It will be my guess that with those altitudes, you will need the max flow possible to get a carb that size to work well.....That would mean a good flowing pipe and silencer as well.....
As for the idleing, the main and needle won't effect that...Just pilot jet and air screw...How does it run when riding it?
Hoodlum

[squirrel]

have dual intake and k&n filter rev pipe and silencer, I understand the different circuits for the carb and am familiar with tm carbs as that is mainly what is used on our sleds, problem is this carb doesn't have a air or fule screw for metering idle circuit just pilot jet. It starts perfect with no choke so that tells me its rich idles a little rough but not terribly bad wont run at all just starts cutting out after you give some gas it is basically fouling the plug sitting at idle and loads up egts barely pull 800 change plugs while its hot and it runs better till it fouls that one, my power jet is completely closed.