So I finally got my DT to start up (after spraying a little ether in the intake), but it's idling at full throttle. It is dripping gas when I turn the gas on so I'm thinking my float is not set correctly in the carb. My question is would incorrect float set cause both fuel spillage (from the little nipple on the back side of the carb) and running full throttle at idle? I'm also wondering if the needle in the carb is not closing the jet where the fuel comes into the carb..

So I finally got my DT to start up (after spraying a little ether in the intake), but it's idling at full throttle. It is dripping gas when I turn the gas on so I'm thinking my float is not set correctly in the carb. My question is would incorrect float set cause both fuel spillage (from the little nipple on the back side of the carb) and running full throttle at idle? I'm also wondering if the needle in the carb is not closing the jet where the fuel comes into the carb..

Don't know about the dripping fuel, but experience tells me to check the carb slide is in the right way round, cause if its not the engine will rev its head off

Might your throttle cable be stuck on,

You should give the carb a good clean as if you dont you will keep having small probs.

While you have carb off you can check that everything is in right and that you dont have a worn needle or seat.

The float could be stuck causing the dripping of fuel, (either ither or) you should take carb off for cleaning and checking. Youll be glad you did !

ok thanks. i'll take a look and report back what i find. If damaged I'll try to get some pics and post em too for the benefit of others.

Two seperate problems here I think. sort the float height out

Check the condition of the that valve seat, see if theres a ring worn around the pointed end, replace as necessary.

The high revving can be an indication of an air leak. I take it you have not had this bike running before? If not it's possible that the crank seal (magneto side) needs replacing. As a test remove the cover and start the engine, then use a can of WD40 with the straw attached and spray a jet of the stuff towards the crank seal (through the slots in the flywheel)

Notice if it has any effect on the way the engine runs. If it does...you get to change the seal.

Don't know about the dripping fuel, but experience tells me to check the carb slide is in the right way round, cause if its not the engine will rev its head off

Yup this was the issue - slide was all the way up so fuel was just dumping in.

It's still dripping fuel though so next is to check the float height (should have checked it when i had it off).

I took the carb off and adjusted the float, it was about 1mm too high (so was at 22mm). I set it to 21mm but it's still dripping fuel. Then set it to 20mm and still dripping fuel. The float seems to be working and the little nipple that the float actuates is moving just fine (i take it that is what let's the fuel into the bowl??). By the way i can start it and keep it going as long as I stay on the throttle at least a little bit, but I do need a bit of ether to get it started - i'm guessing this happens because it's getting flooded out, from the dripping fuel problem. any ideas?

you need to examine the float valve. see if there is a noticeable ring worn around the poited end, or if there is a flake of rust or something stopping it from closing, take care there is a fragile gasket under the brass seat, see that it is fitted and intact. if in doubt you need a new one.

Hi I had a similar problem with my dt250mx.

Check out my post on another site, would think your dt has the same set-up.

http://www.aircooledrdclub.org.uk/forum/forum_posts.asp?TID=24037&PID=180444#18044