hard to start bike xr250

well i took out my bike i picked up last weekend for the first time. i had a great time and overall i was very happy with the bike, except for one thing...it can be a real bitch to start sometimes. it usually takes no less than 10 kicks to get the thing going. my starting routine is this-

put the choke on half way

pull the decompression lever and kick the bike

let go of the decompression lever and find tdc and kick it hard.

i am pretty sure it is the jetting and possibly the valves need to be adjusted. im going to try and adjust them going by the article posted at the top of this forum.

specs on the bike-

97 xr250

whites bro e-series exhaust

before i ride it next i am going to-

*pull the snorkle

*grind the header welds down

can anyone give any suggestions on where to start?

Yeah i would check your valve clearances. why are you using the choke if the bike is all ready warmed up

If it is hard to start, start with the valves. Check your plug. Check and clean the fuel lines and petcock assembly. Good luck. :thumbsup::thumbsup:

this is how it SHOULD start.


-full choke.

-turn idle adjustment up 2 turns

-decomp in, kill switch held, kick it though about 8 times (this is really important if it hasn't been ridden in a while and has no gas in the carb)

-kick till you feel the hard spot of TDC,

-pull decomp and get the kicker JUST PAST TDC,

-give it man-sized kick.

a properly jetted bike with proper valve adjustment and a good plug should start in 1-3 kicks. run it for a few minutes, or until it begins to run rough, then move it to half choke, once it's running nice and strong and starts to stumble a bit, take it off choke. then take your idle back down to normal. i started our 250 these last couple days in 40 degree weather had no problems at all. the whole warm up takes 3-4 minutes, tops. longer if the air is colder.

warm (as in, you just dumped it or just stopped to talk about that last trail, and need to get it started again)

-NO choke.

-NO idle adjustment should be needed.

-some guys hold the decomp and kill switch and kick it through 5-10 times to clear the cylinder and get some fresh, cool air in there.

-find TDC, hold decomp lever (let off kill, obviously) and kick it just past TDC.

-man-sized kick, should fire right up

kicking it through with the kill switch and decomp lever held seems to be more important when the bike has dumped and might be flooded. i almost never do it because the bike fires right up once warmed. it can be tough to start after it's dumped, generally because it's flooded. usually those times when i find my GF in the dirt with the bike all wadded up on the trail dumping gas out the overflow. then i know it's going to be work. sometimes it will just start. sometimes it will need to be kicked through with kill switch/decomp 12 times. sometimes we just need to wait a few minutes, sometimes i have push-started it. when it's this bad i can smell the fuel, there's no doubting that it's flooded. occasionally holding the throttle WFO and kicking it will work.

the most common cause of hard starting is poor valve clearance. also, make sure your manual decomp isn't engaged.

My $.02

Since replacing the spark plug resistor with a piece of metal, my XR starts soooo much easier. 5 minute mod...

Totally agree with Bobby,

However, I would add that when you are trying to clear the carb - apply full throttle when kicking. Once you have TDC let go of the throttle.

Kevin in the Northwest


And don't forget to let go of the comp release before kicking to start.

would going to a 48 pilot jet help or should i adjust the valves and do the resistor mod first?

resistor mod to me is total shite. save that for when you're bored and have nothing else to do. if you pull your plug out, put it back into the plug wire, close the garage door and touch the plug to the frame while kicking it over, you should see a nice STRONG blue spark. once you see that, screw the resistor mod. 1st things first.

1. check valves.

2. check plug so you can see what you're jetting is like.

3. change plug and jetting accordingly.

4. let us know if these two things don't help.

and listen to the other two fellows who posted after me, they are correct in both instances.

thanks. i ordered the feeler guage for the valves so ill get that going when it gets here.

when checking the plug for jetting, do i need to check it at idle,1/4,1/2, and full throttle?

thanks. i ordered the feeler guage for the valves so ill get that going when it gets here.

when checking the plug for jetting, do i need to check it at idle,1/4,1/2, and full throttle?

yeah idle, 1/4, 1/2, 3/4, and WOT. It is important that you do the check in 2nd or 3 gear under load and to pull the clutch in and hit the kill switch simutaniously while the throttle is still at said throttle position. Cutting the throttle before hitting the kill switch will give you a false reading. Plug color should be medium brown to light tan possibly getting lighter as you increase trottle position

is it safe to try and just go to a 135 main jet like i have read that most people do, or should i got the extra length and check the plug? i would like to avoid having to check the plug because i live a pretty residential area and have no where to really hold the bike at wot in 2nd, or is this something i should do next time i take the bike out to go riding?

i know these questions are pretty basic but this is my first bike so im just trying to figure out the best way to go about these things.

Thought I'd throw this into the fray as well. Over time my XR400 was getting harder to start cold. I could dump the bowl, and get it going. I went through the carb, thinking the float was sticking or needed adjustment, but didn't find anything. But flooding kept showing up as a symptom. The best and simplest thing I've done is to make sure to turn the fuel valve off between rides. Without any clearing, I can usually get my bike started in 1 or 2 kicks with the choke full on after tuning the fuel valve on.

When I dump it, it's a pain, but similar drill. Turn the fuel off, clear the engine with the decomp lever and a few kicks. Kick the snot out of it a few times in rapid succession and it starts. Turn the fuel valve back on quickly once it starts.

I stepped up to a 50 pilot jet/135 main jet and adjusted the fuel screw about 2 1/4 turns out, starts 1-2 kicks.....feel around for TDC then kick hard, mine is Gordon modded also

i know this thread is old now but i just wanted to post an update. when i bought this bike it was hell to start. i ended up adjusting the valves, rejetting to 135 M and 45 P with the fuel screw 2 1/4 turns out. the main problem was that the stock pilot jet (45) was totally clogged up. there was about a pinhole size area that was still open when i held it up to a light compared to the new 45 i bought that had a much larger opening. i put in a new plug for good measure and adjusted the fuel screw and now the bike starts on the first kick cold or hot if i find TDC before kicking.

for anyone that has a hard starting 250 i would deffinately recommend checking the pilot jet to see that it is open with no build up.

Good info and thanks for reporting. I see people putting an unprecedented 50 pilot jet in a 250 and have to look to your discovery--check the pilot for blockage.:lol:

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