cold weather starting

[dolphinfantn]

I just changed out the main jet on an XR 250 to 135, removed snorkle, UNI filter, oil change, new plug......so

The bike was seemed very cold natured and took many kicks to finally start. ONce it did start, it would run for aprox. 15-20 sec. and then die. it did this about five times until it finally warmed up and was fine after that.

my question. is that typical for cold weather start up's. also, I do use the decompressor several times before kicking it, say three or four times with the kill switch also.

anyone else experience this?

thanks as always. (the knowledge here is unreal and for someone new to all this I am really thankful) 😢

[MN_XR420]

Yup she is a cold hearted beast until warm, open choke wide open, start her up, blip throttle, put choke to half, let run a min, blip throttle few times, turn choke off, she's warm.. I find it helps to ride it around ur shed/garage a few times while she is just warm, get the oil moving everywhere. Dont jump on and ride her hard till she is above 150 or so, if you dont already have one, get an xr's only oil temp dipstick.. 😢

Easier to start with 48 pilot as well if you went up one on the main..opened up the airbox etc...

[msuncy]

Id like to see the size of your shed hahahaid have a job riding around mine!!

[98xr250]

define cold?

what your bike is doing is normal if the pilot jet is the same one as for summer,

stu

[MN_XR420]

Id like to see the size of your shed hahahaid have a job riding around mine!!

the outside of the shed or garage u dork.

[dolphinfantn]

cold as in 35 degrees outside. have not changed the pilot jet, only the main to 135. will take a look at that now however.

thanks

[dirtsquirt101]

My garage is on top of a small hill, so when I pull my bike out of it I just pop-start it down my driveway. It usually fires up when I do this but if not should fire first kick. It's probably unnecessary but its easier than kicking it over several times if it doesn't want to start. And if you can clear it this way if you want and not have to keep kicking, either way its win win. 😢

[Red_Snapper]

You probably don't need to change the pilot jet. Just turn the fuel screw out (richer) a half turn or so--unless you are already at 3 turns out, then the next bigger pilot is in order. Turning up the idle speed a turn with the big black knob (expressly for this purpose) is helpful. It's your manual fast idle mechanism. You'll need to turn it down again once its warmed up. This pilot mixture adjustment is a seasonal ritual.

Synthetic oil spins alot easier than dino. The "pour point" is ridiculously low, whereas dino oil is congealing and slowing down the cranking speed all 4strokes crave.

Gasoline in the summer is formulated with a lower vapor pressure too. If you expect good starts in the winter, ditch last season's gas. The gas isn't "bad" it's just the wrong VP for the temperature.

[dolphinfantn]

You probably don't need to change the pilot jet. Just turn the fuel screw out (richer) a half turn or so--unless you are already at 3 turns out, then the next bigger pilot is in order. Turning up the idle speed a turn with the big black knob (expressly for this purpose) is helpful. It's your manual fast idle mechanism. You'll need to turn it down again once its warmed up. This pilot mixture adjustment is a seasonal ritual.

Synthetic oil spins alot easier than dino. The "pour point" is ridiculously low, whereas dino oil is congealing and slowing down the cranking speed all 4strokes crave.

Gasoline in the summer is formulated with a lower vapor pressure too. If you expect good starts in the winter, ditch last season's gas. The gas isn't "bad" it's just the wrong VP for the temperature.

Are you referring to the idle adjustment, or the turning the fuel screw out when you said the pilot mixture adjustment being seasonal? I think I am asking that right, I'm a few beers into a Christmas party. 😢

[98xr250]

cold as in 35 degrees outside. have not changed the pilot jet, only the main to 135. will take a look at that now however.

thanks

unscrew the pilot jet another turn or so, if thats ok for you then so be it otherwise its going to be necessary to change the pilot jet~$3.00 no big deal.

go up 2 or 3 points you'll be fine.

stu

[Red_Snapper]

Are you referring to the idle adjustment, or the turning the fuel screw out when you said the pilot mixture adjustment being seasonal? I think I am asking that right, I'm a few beers into a Christmas party. 😢

Ahhhhh, beer goggles...

Turning the fuel screw out (richer) in colder temps is the seasonal pilot mixture adjustment (cold dense air needs more fuel). If you can't get what you need before 3 turns out you need the next bigger pilot. The fuel screw adjusts the pilot mixture for the low throttle range (idle mostly). The size of the pilot jet just defines how much fuel the fuel screw has to work with for adjustments.

In the cold seasons, your warm season fuel screw adjustment is too lean and that's why the anemic cold starts.

[dolphinfantn]

Ahhhhh, beer goggles...

Turning the fuel screw out (richer) in colder temps is the seasonal pilot mixture adjustment (cold dense air needs more fuel). If you can't get what you need before 3 turns out you need the next bigger pilot. The fuel screw adjusts the pilot mixture for the low throttle range (idle mostly). The size of the pilot jet just defines how much fuel the fuel screw has to work with for adjustments.

In the cold seasons, your warm season fuel screw adjustment is too lean and that's why the anemic cold starts.

Well that makes good sense....... I also think I try and give it some throttle to compensate or try and get her running quickly and strong, which causes it to die almost immediately. MAR, you seem to suggest just letting it do its thing right after it fires and the choke has been moved to the center position. Gonna try that and the fuel screw adjustment also. I'm guessing that will fix the issue to some degree.