revs hard on start up

[webi]

i have a 2 stroke yam yb 100 1988 i took it out for a ride and when i came back the revs was slowly increasing so i had a look at the carb couldnt see anything wrong so put it back together

the next day started it seemed ok and idled but this was cold so i took it out but it was sluggish and when i changed down gear i had to keep the revs on and when i stopped had to keep revving it.

had another look at the carb and noticed the split pin had come out of the top of the throttle stop rod and was just sitting in the carb bore so i put it back in with a new split pin and made sure it wouldnt come back out now when i start it it revs so high on startup i dont dare leave it on so i turned it off straight away

im also wondering if the throttle stop rod is the rod that attaches onto the end of the screw ontop of the carb that makes it idle?

[Airhead]

webi much as I would like to help I have no idea what you're on about. if you dont know the proper names of things you should perhaps use pictures.

[webi]

webi much as I would like to help I have no idea what you're on about. if you dont know the proper names of things you should perhaps use pictures.

this is the bit that fell out i think i might have put it in different to what it was as it says something about notches which makes it lean out the mixture would that make the bike rev its tits off?

[Airhead]

Thats the carb needle, now the clip (you called a splitpin...ugghh!)need to be in the correct groove...I dont know which this is bu if you dont try the middle one.

As for the revving I suspect you may have fitted the throttle slide in the wrong way, if you see the cut-away section at the bottom...well this should face the air filter ...not the engine. If you have put it in wrong the slide will be full open. You will see there is a groove down one side, this aligns with a peg inside the bore and keeps it all straight

Have you got a manual? this will tell you the correct clip groove to use

...Paul

[chris66]

my moneys on ogoab, you have it in backwards.

[webi]

my moneys on ogoab, you have it in backwards.

on my yb youve got where it connect to the engine but i dont know where the air connect onto but it isnt like a normal carb i can see the throttle slide if i take the casing off where the carb is in with the oil pump i think the air goes onto the carb in the same sort of way as the fuel does my carb also does not have a butterfly valve will take some pictures tomorrow for you

[Airhead]

Does you carb have a slide like in the picture you linked?

If the answer is yes, then put it in so that the cutaway at the bottom of the slide...faces the air filter, You will see that the slide goes right down to the bottom as the spring forces it down.

[webi]

Does you carb have a slide like in the picture you linked?

If the answer is yes, then put it in so that the cutaway at the bottom of the slide...faces the air filter, You will see that the slide goes right down to the bottom as the spring forces it down.

the slide is about 1 cm maybe less from the bottom of the bore in the carb and the air filter isnt connected by a big pipe on the carb it is a little pipe on the side

edit: ill take some pictures tomorrow im not very good at explaining tbh

[up.yours]

i put the slider in back to front on the yam,,,mine did the same....lift out the slider ,,twist in opposit direction drop it back in,,,job done...as ogb said..

[webi]

i put the slider in back to front on the yam,,,mine did the same....lift out the slider ,,twist in opposit direction drop it back in,,,job done...as ogb said..

slider was in the right way blew out the jets and air ways and now it runs spot on thanks guys

[up.yours]

good ,well we will see you at squires cafe then.