Tim Hancock or Honda XR 250 owners....cold start problems

[Dueller]

I have a late 90's vintage Honda XR250 (4 stroke) dirt bike, It is almost impossible to start when cold....once warmed up it starts with half a kick. Gas is fresh, carb is clean, new plug. Suggestions on choke settings, use of comp release, throttle position when starting cold?

[Tim Hancock]

While I never owned that exact bike (but have started and rode them while already warm), normal procedure IMO would be choke on, throttle closed. If that did not work, I would crack the throttle slightly and try again. Something probably is screwed up if it is that hard to start. The tiny pilot jet might be partialy plugged or maybe someone screwed with the jetting or the airscrew at some point in it's life. With my luck lately, without seeing/trying it, my best stab in the dark is a plugged pilot jet due to the crappy formulation of gas in the past year or so. I know you said you cleaned the carb, but unless you visually verified that the tiny pilot jet is actually unplugged, that is my initial gut diagnosis. All that said, it could be anything.

[Dueller]

Sorry , Tim...thot you had a thumper. Thanks for the stab at it anyway. I'll pull the carb and check it.

[SLO-BOB]

Open gas petcock and let sit a minute. Crack the choke open just a hair. Try "no gas" for a few of kicks, then just a hair on the throttle for a few kicks. If it starts, note procedure and repeat in future. If not, check plugs. Wet? Dry? Wet your flooding - obviously. Wet or dry, you may need to adjust the float. Will it start cold with a shot of starting fluid? Does the XR have a battery?

[911boost]

Make sure you are 100% positive you have the exact correct spark plug. My 2001 CR250R was an absolute nightmare to start, out of the blue, and lo and behold I had swapped out a plug on the trail once, and when the bike was warm it started just fine, cold, no way no how I could get it to start. I evne replaced the coil thinking that was the problem.

Bill

[on2wheels52]

I have an '84 XL185 that gets ridden once/month or so. Takes a few prods with full choke to get any signs of life but always fires up eventually, even with year old gas.
Jim

[charleskieffner]

as an owner of a 1985 xr-350rf, since new, original owner, i may be able to help. my xr served me 14 years 364 days of ungodly baja/calif/new mex/az/colo/abuse. from below sea level to 14,000ft elevation. i have since had xr's only zoom out the motor and a frame up restore with ktm 500xc upside down forks.

every known speed goodie has been put into this.


anyway numero uno cold start issues on 4 strokes is usually valves havent been adjusted correctly. everyjuan thinks fuel. well dump the fuel and keep kicking. good luck.


make sure valves adjusted to spec. make sure, then throw in plug, gap correctly, then check your decompression lever for correct play. if cable bagged replace and then adjust as per manual.

come on its fuel/air/spark . place piston at TDC and kick like hell. if no start check stator.

[Tim Hancock]

Originally Posted by Dueller

Sorry , Tim...thot you had a thumper. Thanks for the stab at it anyway. I'll pull the carb and check it.

I have and have had plenty of four stroke Hondas as well as two strokes. Something is wrong if that bike won't start easily. As I and others have eluded to, it could be several things, but assuming good spark, stock bike and fresh (less than a month old) gas, I still think the carb is the culprit. Has the carb ever been adjusted by anyone? If not, then it probably has some crap in it somewhere. If it has been tinkered with at some point in it's life, then I would check the jet sizes and check a manual or on-line somewhere for stock air screw and needle clip positions. An XR250 should not be all that hard to start whether using compression release or not.

[Tim Hancock]

FWIW, I tried to start an old Honda QA 50 last night that had 6 month old gas with stabil in it and it would not start. A few years ago, this bike had sat for over a year with non stabil treated gas and still started OK. Last night I had to drain the tank and carb and put new gas in it. It started first kick! I used to make fun of folks who always worried about having fresh gas in their small engines, but now with the recent god awful gasoline formulation, I am going to have to figure a better way of dealing with all my gasoline powered occasional use tools/toys.

I also just had a generator with 6 month old gas (with stabil in it) not start for me when we lost our power last week. I ended up having to tear the carb apart to clean it out. I think I am going to buy some 100LL avgas and go thru the hassle of draining seasonal gas and running a bit of the avgas thru the things prior to seasonal storage. Avgas will not varnish up carbs for a long time.

[charleskieffner]

yep if it doesnt have a cat, slap av gas in it. end of subject. barnone easiest fix for crap that doesnt run for long periods.

since there is no battery on a xr, xl's yes, xr's no, if ya aint got spark, and ya got gas(fresh), and air is free, then i would suggest aside from stator, the coil.

no sparky no run.

man my honad generator sits for years and then starts within 4 pulls with avgas. no varnish in jets.

same with my xr. my xr died because of a broken valve spring. 14 years 364 days or some crap. amazing motor. all i did was adjust valves/decompressor, change oil every 200 miles. 20/50 valvoline with a new filter.

amortize out initial purchase price of $2500 bucks from western honda scottsdale az and 15 years of unreal abuse. pretty cheap thrills.

if ya need parts call xr's only and ask fer reverand roy(a checker m.c.-we were sun offroad/m.c.) he can steer ya thru the fog.

its a kiehen carb more than likely, blow air thru all jets/spray the hell outta it with some carb cleaner/make sure tank and or inline fuel filter doesnt have crap and kick like hell.

but my finger would be pointed at spark, then valve adjust/decompressor adjust. find TDC and kick like a mutha.