Bike won't start

[trial_07]

Hey guys,
I've been absent for a week now and just came back home tonight. I tried starting the CRF250R just to warm it up a bit and hear the sound you know. The bike doesn't want to start. I suspect it's cold weather because it is currently -5 degree celsius. After so many trials, I suspected the plug could be fouled. So I changed the plug (other one came out black). Bike won't start again. It has been very cold all week long, is it normal to have such difficulty at starting it? Any tips? Should I worry about anything? The bike ran great last week end.
Thanks.

 

[Matt90GT]

check the hotstart. It is probably stuck open.

if that does not help, then clean the pilot jet.

 

[junkjeeps]

Another thing you can try is draining the float bowl. I've seen where they won't start on what's been sitting in the bowl for a week or two. They like it fresh.

 

[trial_07]

Ok I'll try draining the bowl. How do I know if the hot start is stuck (I'm new at that stuff)? Should I try starting in 3rd behing the four wheeler or something? Thanks for the replies.

 

[Ol'89r]

Ok I'll try draining the bowl. How do I know if the hot start is stuck (I'm new at that stuff)? Should I try starting in 3rd behing the four wheeler or something? Thanks for the replies.

troll_07 :whoa: Oops, I mean trial_07 ;) jk

Don't pull it behind anything. If there is something wrong with the engine, pulling it may do more damage.

Chances are, you are flooding it when trying to start it. Keep your hand off of the throttle when you kick start it. Grab the right side at the handlebar instead of the throttle until you get used to it. The carb on your bike has an accelerator pump in it. Every time you twist the throttle, it pumps raw gas into the engine.

If you think the engine is flooded, twist the throttle wide open and hold it open. Then kick the engine through about 8 to 10 times. Then shut the throttle and try to start it without giving it any throttle.

The way to check the hot start is to disassemble it and visually check it for dirt or a bad seat. Refer to your manual for this.

You can try to bump-start it. Put it up in 2nd gear and have one or two of your buddies push you by hand. Hold the throttle wide open and keep it open until it pops. I don't recommend pulling it behind a quad or a car.

Also, if you bought the bike used, do a compression check and check the valve clearance. Tight valves will cause your bike to be hard to start.

Good luck with your new bike. :cool:

 

[trial_07]

There are no problems with the engine, it ran great last weekend and the valves were adjusted not long ago, piston and rings were changed too (he showed me the old piston and it looks new). The one who sold it to me is coming tomorrow to show me how to start it and finalize the paper work, he says there's a ''special trick'' in cold weather.

Ol'89r, if the engine is flooded and I hold the throttle wide open and kick it ten times, wouldn't it flood even more (I'm a bit confused)?

Am I supposed to change the plug every time? They cost 20 bucks and are a pain to change!

Sorry for being a troll lol. Thanks for your help! It is appreciated.

 

[BSWIFT]

Holding the throttle wide open only actuates the accelerator pump once. Holding the throttle open and kicking thru several times allows maximum air flow thru the cylinder. If the plug is fouled, the carb will need some adjustments. My YZ450F fouled plugs badly until I had a shop adjust it. Never replaced after that.
PLEASE take the advice about bump starting. Too many people are hurt pulling a bike behind a car or quad trying to start a bike. I have a friend that doesn't walk very good now having learned that lesson the hard way.

 

[Ol'89r]

Ol'89r, if the engine is flooded and I hold the throttle wide open and kick it ten times, wouldn't it flood even more (I'm a bit confused)?

Am I supposed to change the plug every time? They cost 20 bucks and are a pain to change!

Sorry for being a troll lol. Thanks for your help! It is appreciated.

Trial_07

BSWIFT did an excellent job of answering the flooded engine question. :cool:

You can allow the wet plugs to air dry or squirt them with some carb cleaner or brake clean and compressed air to dry them out. I have had the same plug in my CRF450 for over a year.

Don't worry about being a troll, ;) I was just messin' with ya. :debil:

I think your biggest problem is just getting the starting procedure figured out.

 

[trial_07]

The one who sold it to me just came. He took the bike outside, kicked it 3 times slowly, twisted the throttle two or three times, opened the choke, kicked it with the throttle closed. It started right away making me feel kinda stupid lol. Thanks for your help everybody! I won't lie that it is a bit harder to start than the 125 though, I hope I get to know the bike fairly quickly.

 

[jason33]

-- as for the throttle wide open - it also sucks in fuel -but more air ,allowing it to clean out the flooded cyl

 

[Fireboy121]

Hey Trial 07, I too just bought a crf250r, Mine is also very difficult to start, even when it's been warm outside. If you figure out a trick let me know, otherwise I'll bring mine to a shop to check everything (valves, piston, etc) on it.