Jump to content

DTR 125 Help again please


Paullaith
This post is 4291 days old and we'd rather you create a new post instead of adding to this one. You can't reply in this post.

Recommended Posts

More problems with my DT lol and need help as im learning slowly. Basically when you rev it the revs drop back down slow, ive tried wd40 round the cylinder head and inlet manifold and ive cleaned the carb but still no joy. Has anyone had this problem before?

Link to comment
Share on other sites

Do you want an ad-free experience? Join today and help support the Yamaha Owners Club.
  • Moderator

try turning in (clockwise) the air mixture screw 1/4 of a turn and test again, if same repeat. If you cant sort it before the screw gentlly seats you might have to fit a bigger pilot jet to the one fitted now.

This assuming you have no air leaks anywhere!

Link to comment
Share on other sites

  • Moderator

Ive tried the screw it just made the idle go up. There is defo no air leaks ive made sure of that.

which screw did you try? I didnt say the idle AKA 'throttle stop' screw...I said the air mixture screw, its a small one and may be recessed somewhere on the filter side of the carb slide

Link to comment
Share on other sites

I would order the screw from Yamaha or even buy a replacement carb from ebay. It seems someone had tampered with your carb alot and is probably the main cause of your problems. Spend 30-50 on a nice condition one on ebay and have it apart, clean it, check jetting and then set up yourself to know its all correct.

I beleive the air screw should be 1 and 1/2 turns out from fully screwed in.

start with both air and idle all the way in.

Then use the idle to bring the revs down to 1.5k

Screw the air screw 1/2 turn ( this will bring the revs up)

Screw the idle out again gently to bring it down to 1.5k

Screw the air screw 1/2 turn more (now it is 1 turn out)

Screw the idle out again gently to bring it down to 1.5k

Screw the air screw 1/2 turn more (now it is 1 and 1/2 turns out and in its optimum position)

You can now adjust the idle screw to whatever you want the idle engine speed to be ( 1- 1.5k i would guess)

***Check that 1 and 1/2 turns is the optimum setting but I have found that to run nicely***

When you say rounded? The air screw is a flat head screw, are you sure you are looking at the right one? If i get a chance I'll photo a carb and circle and label the two. The air screw is in a recess to the right of the idle as Airhead said. It's kinda 'down a tube'.

If you think the air screw is not set right, avoid running the bike. Too much air will cause the mixture to be lean and the engine will run too hot and you'll hole the piston. Without being rude, if you don't know what you are doing, research it before you mess around or you'll learn the hard way.

Link to comment
Share on other sites

Ok thank you great info il have a look for a carb i think as mine isnt looking in the best condition anyway. Also my bike was running fine the other day its only just started doing this and i havnt touched any thing.

Link to comment
Share on other sites

×
×
  • Create New...