Need big bike help...

[6IX]

Well i have a 02 yz250f that i got in on trade, the guy i got it from says it doesnt run, but heres the thing... if i bump start the bike it will fire right up and run good, but i cant get it to idle, and if i do get it to idle, and then rev it, it will rev up then not rev back down until i turn the idle down. Also i cant get the bike to start by kicking it for the life of me, wether its hot or cold. I got it to fire up from kicking it once but it took like 549 kicks.... It has outstanding compression, great spark, clean plug, just replaced the pilot jet.... Im so lost with this bike. If i could get it to fire up from a couple kicks and idle like it should id be extremly happy. What do you guys think?

[PlanetMinis.com]

[redirt78]

I would start by cleaning the carb, float, bowl, jets, lines, etc... Check out the air filter too, might be nasty



Just re read your post, looks like you probably already checked all that out if you replaced the pilot jet

[6IX]

I would start by cleaning the carb, float, bowl, jets, lines, etc... Check out the air filter too, might be nasty



Just re read your post, looks like you probably already checked all that out if you replaced the pilot jet

Yep, cleaned everything out already, and the air filter is properly oiled...

[redirt78]

I'm far from an expert but what about the line from the the tank to the carb? Might have some junk in it and fuel only gets through when forced like when bump starting.

[doopsx3]

sounds to me it has a vacuum leak

[wingding]

the early years of stroke were VERY finicky. i had an 01 yzf and it was the same way if you shut it off it would start if your fell and it died you were... kicking 549 times... BUT it would bump start fine. dont take this the wrong way but do you know the "routine" for starting these bikes. they are not like kicking a 2t where you can snap kick them , you have to kick HARD.ill wait for your reply before i address this further. if this was my bike i would check a few things.



1- carb replacing the pilot jet doesnt mean its all cleaned out. i have been riding /racing for 30+ years and have never had to replace a pilot jet on a properly jetted bike. you need to clean ALL the air passageways all the fuel passageways , make sure theres no burrs in the slide prventing it from sliding smoothly, make sure the float is set right etc. be VERY thourough whos knows what was done to this unrunning bike before you got it.



2- valves- make sure the valves are set to spec.( this is my bet as to why the bike wont run). just because you have a ton of compresion doesnt mean the valves arent out of spec.



3- spark how is the spark and also how is the plug. if it looks okay throw it away anyways. 5.00 spark plugs sometimes work wonders.



keep us posted Brad

[6IX]

I'm far from an expert but what about the line from the the tank to the carb? Might have some junk in it and fuel only gets through when forced like when bump starting.

I replaced that 2 days ago... didnt change a thing.

sounds to me it has a vacuum leak

I didnt know these had vacuum lines...? Where do they go to/come from?

the early years of stroke were VERY finicky. i had an 01 yzf and it was the same way if you shut it off it would start if your fell and it died you were... kicking 549 times... BUT it would bump start fine. dont take this the wrong way but do you know the "routine" for starting these bikes. they are not like kicking a 2t where you can snap kick them , you have to kick HARD.ill wait for your reply before i address this further. if this was my bike i would check a few things.



1- carb replacing the pilot jet doesnt mean its all cleaned out. i have been riding /racing for 30+ years and have never had to replace a pilot jet on a properly jetted bike. you need to clean ALL the air passageways all the fuel passageways , make sure theres no burrs in the slide prventing it from sliding smoothly, make sure the float is set right etc. be VERY thourough whos knows what was done to this unrunning bike before you got it.



2- valves- make sure the valves are set to spec.( this is my bet as to why the bike wont run). just because you have a ton of compresion doesnt mean the valves arent out of spec.



3- spark how is the spark and also how is the plug. if it looks okay throw it away anyways. 5.00 spark plugs sometimes work wonders.



keep us posted Brad

Yes i know the proper routine for starting the bike, i use to have a 01' yz426f... just never had a problem like this before. Im going to give the carb a once over tomorrow and test it... if nothing im gonna tear her down and check valve clearances...



Thanks for the input so far guys.

[LongMooie]

i came off a 2stroke then 6years without riding and just got a 08 crf450

i hated the bloody thing when i firsts got it i couldnt start the whore to save my life

i was ready to place an ad looking to trade for a 2stroke but when i took the bike to honda just to have them give it a once over and they showed my the ways of the 4 banger i start it fine

i like it now apart from after i drop it and i dont have any energy left in me lol



as for the air leak if you can get it started spray some carb cleaner around any areas that could leak if theres a leak your bike with rev up alittle more