[Longw8]

I just bought a left over 07 CRF150R for my son. When you kick it over it is very hard to turn over. Once you get past the initial 'Lock up" it turns over easier. The engine then spins till the next compression stroke (if it doesn’t start). When you go to kick it again its "locked up". I use the term "locked up" because I'm not sure how to describe it. As you kick it over it either won’t move or turns a small amount and stops. You can manage to get past the compression stroke but it's very tough. I'm not a small guy and have kicked over my share of bikes and this seems way to hard for a 150. It is much harder to kick than my CRF250R or my CR250. All though the closest I ever came to a new bike is my CRF250R with about 18 hours on it. Is this normal and will "loosen up" a bit after a few hours? Once the bike starts, it runs fine (after re-jetting it of course). It is a bit discouraging to my son who can’t even kick over his new bike. A buddy of mine, who has a 450, just came over and had trouble kicking it over.

[captain falcon]

Exhaust valves must be tight, talk to your dealer and see if they can adjust your clearances.

[McCrfman1]

I have had many bikes, some two strokes and mostly four strokes. I currently own a 07 Crf150R, and a 02 Crf450r. I love them both. I also owned a 02 Yam Yz250f that gave me fits to crank! It had the fully manual comp release. Unlike all the latest four strokes that have a auto decomp.
You describe a brand new leftover stock bike, you also say it runs great when it's running, just hard to start.
Of all the bikes mentioned above my valve adjustments have always been to the intake and very rarely to the exhaust. Before I looked at the valves I would suggest trying a different cranking procedure.
There are two ways to crank these bikes.
1. crank and crank and crank until it eventualy runs
2. find TDC (top dead center)
Most people go with crank,crank,crank.
Try this:
Slowly roll the engine through until you find the hard spot followed by a short divet or drop on the kickstarter.This short drop you feel is TDC. You must stop right at the end of that drop. Return kicklever to top and crank with a swift kick. It will take some practice but will pay off.
When it's hot, same drill just use hotstart.
This works great on both my Crf's 3-4 kicks cold. usually first kick when warm.
On my Yamaha, if you did not use the drill, you simply were not going riding. I called it my anti theft protection.
I did master the drill and had many happy hours on it.
Hope this helps.

[sak384]

Wow, that is strange. My son has an 07crf150r. He is ten. He can start it cold or hot with a modest kick 1 -2 tries. Since you just bought the bike why not let dealer give it a look over? Show them what you are describing and see what they say. It sounds like the auto decompressor may not be working. If it gets stuck anywhere in the range while kicking it over that is a problem that i would get corrected asap.