bike starts, wont run

[pudge]

ok this is a 94 honda xr250r, i know is not a trike but bikersville doesnt get many hits. anyway, my buddy brought it over last week for me to look at, it hasnt run in 2 years, ran fine when put away. gas was old, mouse made a nice nest in the airbox all the way to the choke valve of the carb, slide was stuck, carb nasty. i cleaned it all up, new gas, ran wire and compressed air through all the screws, jets, holes....seems to be pretty good, some aluminum of the carb body is corroded but not too bad, got the slide free today. new plug, good spark, good compression, i can kick this thing all day and nothing. i shoot some ether in the carb and she'll turn over, rev up and stall, everytime, if i hit the throttle it doesnt seem to change anything, i can try to flood it and nothing come out the overflow tube of set screw. should i try getting a carb kit? or just junk the whole thing and get a new carb for it? i thought i cleaned it good but no luck... could it be something wrong or clogged in the body of the throttle? also it will NOT pop start either. spark, compression and fuel right? how can i get the fuel.

[rdlsz24]

If you pull the gas line from the tank to the carb does gas run out? Either the gas is not making it to the carb from the tank or it's not making it from the carb to the cylinder or both.

Rob

[outtaline]

your not gettin fuel get some real carb cleaner not aerosol get the liquid and soak it over night then reassemble and try again

[Macs]

Probly the fuel gummed up and clogged the petcock. Try to get fuel out of there. Blow out the fuel line and see what happens.

[pudge]

fuel does drain from the petcock and line. so its the carb, should i just soak that sucker or do a full rebuild

[Erics350x]

The needle valve for the float isnt opening. Take it back apart and see if its sticking in the up position. You could also try tapping on the side of the bowl with the drain unscrewed and see if it free's up.

[pudge]

the slide with the needle in it ,moved up and down just fine. is that the needle valve? or is it the little piece that has a pointed rubber tip on it under where the float attaches?

[Dirtcrasher]

When they sit for that long, I always strip em down to the body, soak them and spray them with carb cleaner and comp air and install a new kit.

You have to be really super thorough after the gas turns to varnish. I also take out those stock filters and just run an inline I can see and verify fuel flow with.

Hasn't failed me yet :D

[CRAZY70MAN]

You need to take apart and soak for 2-3 days if ya' got white corrosion in bowl. That schmit will jack a carb all up:eek: You will be surprised what ya get out when it soaks..... try evaporust.......TSC carries it in oil and spray can section...... works awesome.....

[pudge]

ok, i will soak it in gas and or carb cleaner pull it apart and put it back together, hopefully i can get it going by sunday, we have a ride planned and he wants to go, then he wants to sell the XR and get a trike

[Erics350x]

the slide with the needle in it ,moved up and down just fine. is that the needle valve? or is it the little piece that has a pointed rubber tip on it under where the float attaches?

Rubber tipped under the float

[pudge]

cool, thanks everyone, i having it soaking now and will put it all back together saturday and hope for the best

[pudge]

thanks for your help guys, i soaked it in gas and cleaner for 3 days, blow out the jets and everything. put it all back and she fired right up. it idles pretty good and throttle responds ok, when actually riding it it is very choppy, doesnt cut out but unless your on the gas it doesnt run well at all, when i hit the gas it hesitates, do you think this is the jets? or screw settings? air/fuel?

[pudge]

this is why i hate having to post this is bikersville.... a carb problem is a carb problem. if this was a trike i would have 20 responses by now

[pudge]

ok guys i know some will know what to do here.

i got a new air cleaner, plug, and STOCK carb kit with 118 main and 38 slow.

it had 125 main and 45 slow in it, it has a white bros pipe but no other mods as far as i know

it idles OK now, but not great, it starts kinda tough but better. it back fires like a mofo after revving it or coming down a hill. and it stays revved when riding, doesnt want to come down to idle when its in gear so i need to be on the brakes a lot. i really dont know signs of lean or rich or really what they mean or how to fix it. im sure its pretty minor but im stuck

[Vealmonkey]

Pull the plug and see what it looks like. If the plug is sooty black, it rich, which means too much fuel. If the plug is white looking, it's lean or not enough gas. if the plug is brown or tan looking, it's just right. If the plug is brown and black, just a little bit too much fuel and brown to white mean just slightly not enough fuel. Now back firing could be caused by air getting back into the exhaust. It could be sucked in at the exhaust pipe, which you may need a new exhaust pipe gasket or it coulc be getting sucked in between the carb and the head which would mean you either need new intake gaskets or your rubber intake boot between the carb is either loose or could be dry rotted and have a crack in it. As far as jets go though, the idle jet or the main jet can be too small or too big. And to really tell which is which, you would have to do several plug chops, which is another matter altogether. Best of luck with your tune up. Also I'm figuring that you have your valves and timing properly set. If you don't than those are the first things you need to address before worrying about the carb and such.

[pudge]

ok so i did notice it to run a little better with 1/2 choke, so i figured it needed more gas, i gave the pilot screw 1 turn in and it seems a little better. i have the needle on the middles clip, should i move it up or down? or will i need to change the jets.


i have not checked the valves or timing but this bike ran perfect until it sat in a barn for 2 years and became a mouse nest. could this affect timing and valves?

[Mikeproc]

try turning the air fuel mix screw in or out and see if that helps your back fire.

came in a little late, Vealmonkey set you right, start reading your plug and that will tell you what to do next.