Bike won't start when cold

2008 wr250r. Bike was running fine. Then as winter grew near it started beginning to have trouble starting cold. Runs fine when warm. Has spark. I can hear the pump. I think it's the valves unless someone thinks otherwise. Any body have a manual I can download to do the valves? Or other problems someone may think.

Usually tight valves will make the bike start harder when its hot.

You dont explain what happens, does the bike crank fine?
How about some help with jumpercables? Perhaps the battery is just a bit tired...

Bike cranks fine. I've had a trickle charger on it to make sure the battery is good, I believe it is. I also just checked the valves and I am within spec. I left the gas tank and and getting a new spark plug tomorrow. Just for good measure. The bike only has 4K on it too.

Meassure the voltage on the battery as the bike cranks, if they drop too low, the bike wont fire.
4k for a sparkplug on a 4 stroke is nothing.

The battery wouldn't make sense. I'll check it. I can literally crank the bike 2-5 minutes before it'll start and the battery never dies. I have also tried bump starting multiple times down hills to it not starting either. I've also had full charge on a battery to it not staring right away. On a side note. I cracked the radiator over the summer on a ride, I had to ride out no other option. I had it fixed and the bike ran fine for the first month and then started having problems going into the colder months or colder mornings

Justanotherguyonabike wrote:

The battery wouldn't make sense. I'll check it. I can literally crank the bike 2-5 minutes before it'll start and the battery never dies. I have also tried bump starting multiple times down hills to it not starting either. I've also had full charge on a battery to it not staring right away. On a side note. I cracked the radiator over the summer on a ride, I had to ride out no other option. I had it fixed and the bike ran fine for the first month and then started having problems going into the colder months or colder mornings

Did the temperature light come on when you rode it with a cracked radiator and how long was it in? Is it using coolant? Have you checked the compression? I wonder if a blown head gasket might affect compression making it hard to start.

-morgan

First thing I would check is the valve clearances......hard start is a classic sign of tight valves.

Post stated above. I already checked the valves I'm within spec. The check engine light and temp light came on. Is on because of the fan wire got melted together on that ride. w
Waiting on new fan. It was a little low on coolant when I checked last night. Added some. I still had them same jug which I didn't/forgot to burb the system. The jug level is to about right at the .9L mark. Still have my concerns about the head. The good news. Could be of three things. I changed the spark plug, cleaned the air filter 1500miles since last one. Didn't look to bad. It was about 70 in my garage today. Bike started on second try. Way better from last go. Going to try it in the AM. To see if there's a difference.

Back to the same problem. Took forever to start this morning. I'm lost. I've checked spark, battery, cleaned air filter, fuel pump sounds just like my r6, and valves are in spec.

Blown headgasket making issues? An overly warm bike, down on coolant... Most of the signs are there anyway.

Your battery sure sounds healthy.

How could I check to see if it's the head gasket?