new bike wont run

[funkymunky]

ive recently bough a 2000 yz 250 and cant get it to run. ive had it out only a handful of times, without any problems other than a fouled plug. now i cant get it to start and stay running right. i choked it with a new plug in and finally got it to start but it would just rev up and smoke bad. i run 32/1 fuel, any help would be great, im new to the forum, and am just getting back into riding.

[Macho393]

things I would do are: clean filter and replace when dry...but tacky. Clean boot behind the carb, in sure it has no oil film on it. Check plug to see if its wet fouiled or carbon fouled.Adjust fuel screw accordingly.

[yamracer58]

this my sound dumb but alot of people over look this and i have dont it before!! but do you have gas?? your engine will rev up when it is out!!

also you might have your idle screw up too high and for the fouling plugs you need to rejet your bike!1

hope this helps!!

[funkymunky]

i did run it out of gas before i had this problem, and know 2 strokes can be pretty tempermental, but i mixed some fresh gas using suzuki oil (couldnt find any yamalube)

[funkymunky]

filter was tacky but not dirty, does the owners manual have the setting for the fuel screw, and the new plug is wet with fuel but still sparks when held against the case

[Silver_Fox]

Originally Posted by funkymunky

i did run it out of gas before i had this problem, and know 2 strokes can be pretty tempermental, but i mixed some fresh gas using suzuki oil (couldnt find any yamalube)

Suzuki oil in a Yamaha.....Oh oh there's your problem. JK

Sounds like it may be a vacuum leak in your boot between carb and reed block.

How is the compression?

Also check your reads and clean your carb, sometimes the smallest particle of dirt can mess up your carb.

[funkymunky]

dont scare me talking about compression, ive only had the bike out four times. it sounds like theres good compression when i kick it over, im going to try to check it monday. that was going to be my next step to clean the carb.

[yamracer58]

k the suzki oil will work untill you get the problem fixed but then i susgest draing the gas and gettin yamalube!!

have you tried to start it with the new gas yet?


im thinking maybe an air leak!!

[funkymunky]

drained the gas and tried new gas with no results

[funkymunky]

where would the air leak be? i tried to start it without the air filter, just to make sure that wasnt the problem

[yamracer58]

-drained the gas and tried new gas with no results-

as in no resultes do you mean not starting or do you mean its still reving up

[yamracer58]

the air leak could be anywhere. most air leaks are on the gasket between the cylinder and the crank.

alos check and see if you throttle cable is stuck if it is still reving high!!

hope this helps

[funkymunky]

still wont start

[funkymunky]

i gotta go, thanks for all the help

[dixienw123]

hows the compression man, check that, make sure everything is cleaned(motorwise), and there's no fuel blockages, or air blockages.


{you just received words of advise from #7735...cherish it}

[ridered2]

check the reads clean the carb see if u have good spark

[Vintage Dave393]

If the bike revs high and smokes you most likely have a bad crank seal on the clutch side of the crank. It is letting air and tranny oil into the mix and causing a loss of compression and an overly rich mixture.

[Crazy]

My friends YZ did this and his was because his reeds were sitting in the airbox.

[superrooster]

Well theres your problem, you bought a yamaha if that was a honda it would have started on the first kick . Anyways back to the subjet, check the spark plug, timing, jetting, exhuast valves,top end, float level and make sure you there is nothing keeping the gas from getting to the carborator.

[yamracer58]

also one more thinkg to try!! Take off your silencer!! ive had mine plug up befor and it wouldnt start!!