hi having problems with my dt 125. I started with the engine spluttering when you hit the power band intermittent but getting worse throughout the day now it will start tith the choke only and wont rev at all had carb off cleaned it thought it might have been float setting but there was plenty of fuel in the bowl checked reeds there ok to someone told me it could be the head gasket pulling air in could it do that? someone help me please!!!!!!!!

If your gaskets gone it could be pulling air in, it makes the air to fuel ratio to lean, hence why it needs choke, if it is the head gasket it will need replacing. running it on choke will only ruin the insides, it will be lean then rich at high revs, coking stuff up.

Welcome crawford " Has the bike been standing, [ not in use..] When starting, choke jet is opened via lever/ then the first 1/8th of throttle is Pilot jet, then as venturi builds up needle jet regulates fuel , then wen wide open throttle is Main jet.

Now , sounds like pilot jet needs removed and cleaned,,,

i hope youv'e changed the plug.

yes plug has been changed had carb off and cleaned every jet but will only tick over with choke on wont rev just dies going to have another crack at it tomorrow

Did you ever resolve the problem???? Just wondered what it was.