Ok guys here’s my issue. My stock 08 WR250X has been difficult to start lately. It cranks just fine but is reluctant to light. It will do that all day long and if I continue to crank it and I can smell raw gas from the exhaust. The only way to get it to fire is to hold the throttle open. This problem is pretty intermittent; it will do it mainly cold but not always. Other than the starting issue it runs fine. I have 1400 miles on it and had the first service done at 600 miles. I can’t take the bike back to the dealership due to the fact I live in the U.K. now thanks to the military (not quite the same riding weather as California!), so I have to figure this out on my own. I’m wondering if out of adjustment valves could cause this, but would they go out of adjustment that quickly? I’m running the gas completely out of it hoping it will help but I can’t see bad gas only affecting the staring. I have tried to adjust the idle but that doesn’t seem to help. Could the Throttle Position sensor require adjustment? I’m figuring it has to be simple as it runs fine and doesn’t pop any codes, plus the age of the bike doesn’t lead me to believe it’s major. Any help here would be appreciated.

yes check valve first. usually this is problem with all 4 strokes. if they are out, adjust them and listen to the difference when you fire the bike. big difference. good luck..

Try changing the spark plug. I fouled one last winter which caused difficult starting.

I will check the plug first, hopefully that is the issue. After that i'll dig into the valves. I ll post my findings.

How's the air filter looking? :)

Checking the valves would be the last place I'd go. Seems highly unlikely there'd be that big an issue with a 2008 that's only got 1400 miles.

Check the battery.
Check the fuel pump. (there seems to be an issue with some of those)
Check you gas. Empty the tank and fill with fresh gas from a reputable station.
Check your plug.
Check you air filter. Is it clogged?

Is the bike stock?
Is there a pattern you've noticed as to when it won't start?
Is the problem showing up only when the bike is hot?


Why wouldn't a Yamaha dealer on the UK honor a warranty on a Yamaha? It'd be worth it to check.

I pulled the plug out last night and it didn’t looked fouled, but it was barely torque in. The manual specs the plug torque at 9.4 FT/LB’s and it definitely was not that. I also put in fresh gas so we will see. It was always an intermittent issue so I will give it a few trips before I call it good. As far as the dealer taking care of it, it is over 1 year old (just) so it is out of warranty, plus the dealer here said they won’t touch a US spec bike. They do have the same bike here in England, but they still won’t touch it. I have the same problem with my car and it’s a VW, but because it’s US spec they won’t work on it. It’s wonderful having a brand new vehicle and no warranty!

How long ago did your bike make the trip over, and how long was it away from you all together (drop off, shipping time, customs etc)?

Copa, The military shipped my bike with all my other stuff. It took about 2 months to get over here. I got most of the paperwork stuff handled within 2 weeks of it being here so it wasn’t too bad.

Update; actually installing and torquing the plug seems to help! I’ve put a few miles on it and so far it is good. It was an intermittent problem so I won’t call it fixed till I’ve ridden some more but hopefully……..

crazydog said:

That could explain the smell of raw fuel from the exhaust. The loose plug was not firing due to a bad ground. When you pulled the plug did you look down into the cavity to see if there was any residue build up that could have been leaking out around the loose threads. That would be a good clue that you have nailed the problem. It may be dirty down in that cavity, but you shouldn't see any carbon-like build up in there. Keep us posted on how it runs (and starts) after you have more time on it.

I just had my bike in the shop from poor starting they replaced the fuel pump under warranty. When you turn the key can you hear the pump?

mwakey- I didn't look at the plug hole, but hopefully this is the fix, nice and simple!

Fox- the pump always seems to run fine when you turn the key. When I shipped the bike over here I had to purge all the gas from the tank. You can hear a difference when the pump isn’t moving any gas, (empty thank or internal issues). I am conscious of that sound when I power the bike up now. Im really hoping that was the fix, I’m pretty confident it is.

Thanks for all the help and suggestions!