Bike wont run without choke on??

[enduro100]

HELP! My choke has to be half on to run....

hey guys, i have a problem with my 75 dt 100. First off, when i start it up i have it at half choke. It runs fine when it is like that. But, when it is idling, i push the choke all the way in and no matter how much i rev it, it just goes baaaaahhhhhhhhh and stalls. The egine is warm enough, because i ride it around for 10-15 miniutes. Ive cleaned the carb out, changed the air filter, blew the fuel filter out, and changed the plug. Does anybody have any ideas of what this could be, or past experiences? Help would be greatly aprechiated.

Thanks, enduro100

 

[kelsorat]

To really clean your carb, take it out, fully disassemble and blow compressed air through pilot and main jet. If the bike will not run without the choke, you are running too lean. If you have not changed out the jets, and this is a bike you have ridden frequently, then it sounds like a carb problem.

 

[enduro100]

ok thanks, anybody else got any ideas?

 

[Tyler3386]

Could be an air leak in your intake if its old and cracked. Air leaking in will cause it to be lean.

 

[enduro100]

I have a 1977 Yamaha DT 100cc and for some reason it wont run without the choke on (when the engine is warm). As soon as you give it about a centimetre of choke, it will run fine. But as soon as you give it no choke at all, in about 3 seconds the engine will bog and stall, then will not start again not start unless you give it some choke. I have cleaned the carb, changed the gas, put gas line antifreeze in the gas, replaced the air filter, fuel filter, did a compression test (which passed), adjusted the idle, tried every different spot on the needle, tried new spark plugs, but nothing works. If I do run it with the choke on, it fouls plugs and overheats. It takes mixed fuel, so there is no oil pump. Any ideas what this could be caused by?

Thanks

 

[Garydmx]

Definitely a clogged pilot jet to say the least. Get a high 'E' string from one of your guitar playing friends. This will help to auger out the dirt in the pilot jet. Or buy a new one. Hope this helps

 

[mopar]

check your carb boot for cracks