yamaha 125 starts but dont run right

[yamaha driver]

i bought this from a guy that stopped me on the road when i was riding on my 250r he asked if i wanted to buy a 175 for 50 bucks i get there to find out its a 125 he said it ran great before but not for 3 years so i cleaned the carb with carb and choke cleaner bought a new plug cleaned air filter checked compression which is perfect but will not start with rewind. when you pull it over it like rips your hand off, i broke 2 rewind ropes so i decided to push start it it started in like 6 inches if that but you can hold it wide open and it just stays at like 1/4 throttle. why is it doin these 2 things?? it also smoking more than usual
P.S a day before this it auctaly ran great opened up and everything.
any suggestions would be great thanks

[tri again]

almost sounds like the timing changed.
My guess is that since it ran great the other day.
the spark advance plate may have stuck in the advanced position and wants
to break ropes since it's firing with the piston on the way up....
way too soon on the way up.

You have a manual?
free in the 'world class help' section.
Recheck your timing. Should be easy.

If it has cdi ignition, the advance curve is moderated by that but may also
have a regular spring loaded advance plate under the points
or pulse generator run off the cam.

What else could it be?
new crud from the tank getting into your nice clean carb?

[yamaha driver]

its a 2-stroke so i didnt think it had all that stuff??? i though it all ran off the stator

[tri again]

oops.

Where DO they get spark from I wonder?
Did you get a free manual in the world class help section?
They seem different than the book I have.

Generally, what could make those changes since it ran good and then changed it's mind dramatically
...poor running and
killer pullstart rope resistance.?

The only 2 strokes in my world are my chainsaws and little generator
and for some reason, those are the only things that have not given me any trouble.

Wish I knew.
Surely someone will chime in.

Please post what you find.
I like to learn something new every day.

[just ben]

sounds like water in the fuel. although you said it ran fine the day before. did you happen to switch the petcock to res. In that time period? that would let pick up the water on the bottom of the tank.what size rope are you putting in the recoil? was in new rope or something you had laying around?

[Jason125m]

Water in the fuel x2.. but, did you actually clean your carb, or did you do like most and not take the jets out and clean them properly...

I find a lot of people just dont know how to clean a carb.

Also, what are you mixing your gas/oil at? More smoke = too rich...

[yamaha driver]

ok i totaly drained tank took air hose blew it out cleaned for dirt and such and put gas in a clear jug and let sit for a bit no water in it but a little iso-propohal (sorry for spelling) i took the carb completley apart used like half a can of carb and choke cleaner took the pet cock apart completly cleaned with carb cleaner and dissasembled and put back together. made sure all ports little crevaces everythine was clean. Jason125m i still have the oil injector hooked up and its at its lowest setting. air cleaner is clean i took it off and runs the same choke cable is not stuck. but it still ran exactly the same when i took the cable out of the carb?? same with air screw i turned it all the way in then took it out same... i tried diffrent carb that was on running 125 same thing 2... it doesnt pull over very hard but every id say 3rd pull it like pulls it back in and rips your arm off

[yamaha driver]

and ben i got a brand new 6 ft rope from a polaris dealer same thing thats on 500cc 4 wheelers EDIT and drjoe the killer pull start was like that 2 when it ran good.

[yamaha driver]

and drjoe i couldnt find a manual for this trike i looked for a bit dont think there is one on here but thanks for helping so far everyone. also if this helps i was driving it down are road i went to the end then back up to my house i went around the house then it started to bog a little so i slowed down to 2nd gear then tried going up a small incline to our garage and it woulnt do it just wouldnt open up so i shut if off pushed it to the side on level ground started it by pushing it and never opened up since then... i have a parts trike so if anyone has suggestions mabey switch stators or sometin. just dont feel like doing it if its not that

[just ben]

if it has good compression and your fairly sure its not fuel related I would go onto electrical one componant at a time

[Six Stroke]

You know, they could start an entirely separate forum just for these Yamaha 125/175 "not running right" threads.

[just ben]

You know, they could start an entirely separate forum just for these Yamaha 125/175 "not running right" threads. i have owned both the 125 and 175 the only trouble I ever had was water in the fuel on the 125(which ran just as the original poster explained) and the flywheel hub cracking on the 175. great,fun little machines IMO

[MonroeMike]

and drjoe i couldnt find a manual for this trike...There's "some" info for your machine here. http://www.3wheelerworld.com/showthread.php?126386-YT125-175-Service-Data

[yamaha driver]

ok thanks and not picking on six stroke but ive never had one this bad of shape looks like guy ran it and never maintaned it or just beat the s*&$ out of it. EDIT also trying to start it today when i pulled it over every 4th pull it like its a quiet backfire not load kinda like puhhh. and pumps out alot a smoke. im gonna pull of flywheel make sure that little pin aint sheared on the flywheel makin it off time

[RID3R]

I would listen to whats been said... and also dont ride on the road.

[RubberSalt]

Alright, check these things; carb/air filter, reeds, air leaks, recoil starter is wound correctly.

If it doesn't go past 1/4th throttle, then odds are that it's a fuel issue. Also mentioned that your smoking a ton...
Change the needle clip position on the carb. Try the middle spot or the 2nd notch from the top. You might also have a main jet that is just way to big, try needle first. Make sure your air filter is clean, a dirty filter restricts air flow and creates a larger vacuum in the carb. carb + stronger vacuum=more gas leaving carb.

Recoil starter; If this is wound the wrong direction, when you go to start it, it will fire very early. There wont be much compression before ignition meaning a weak fire. Youll get smoke and thats about it... when you push it, it runs - thats a sign of a recoil wrong backwards.

It is possible that the reeds are not fully closing, this can really hurt things when it comes to starting - take the air box off and put your hand behind the carb after you get it running. If you feel tons of gas on your hand.. or even see it coming out(like i did with mine) then you have leaky reeds. This causes excessive smoke when running and hard starting.

air leaks; could have a bad seal, causing excessive air to leak in. The previous own could have tried and compensate with more gas but never got it right so he sold it.. More gas+leak=never going to run right.

I put my money on carb/filter and recoil.

I run a 32:1 in my 175 and my 125 - they like that number with some good oil (i know i could go leaner but im paranoid)

[yamaha driver]

ok for rider not being mean just saying i wear a helmet. if i ride in the ditch i get b%(^hed at because they bale it around here for hay.. all the fields have corn in or beans so i cant go there... i have no trails around at all except private... all my neighbors ride dirtbikes/ atvs everythin on the road BTW im 10 miles from a little town so im in country.
ive got holared at so many times for driving anywhere except the road so i asked if my noisy trikes (300r) bother any of my neighbors and none care if i drive anything on the road. and rubber salt thanks for the info but i swaped reeds from a running 125 same thing happened. tried all needle postions notin... the main jet in there ran great the same day ... cleaned tank i made sure no water in anything... we wound correctly i made sure of that and i still have oil injector on mine with fresh 2 stroke injection oil. left aircleaner on ran bad took off completley right from carb ran excact same.. when i put my hand behind the carb i feel a little gas not much. i shot starting fluid around boots and head... all gaskets never ran diffrent (P.S. i did it when it was running).... im so confuzzled... thanks for posting

[just ben]

Recoil starter; If this is wound the wrong direction, when you go to start it, it will fire very early. There wont be much compression before ignition meaning a weak fire. Youll get smoke and thats about it... when you push it, it runs - thats a sign of a recoil wrong backwardsIf the recoil were wound backwards it wouldnt work at all. the dawgs in the recoil only work in one direction. and if the engine were turned backward it would fire late not early, if affected at all. depending on the particular engine.I have run many mx bikes and snowmobiles "backwards" just to show that it will

[RubberSalt]

check your plug, see what it says

Still sounds like carb has something plugging it up some what. Tiny something in the main jet or the choke is stuck on. Check the choke isn't on after starting. That choke might be out of adjustment, or cable is busted somewhat.