09 WR450, bog = stall

Hi guys, I’ve just bought a 2009 WR450 two weeks ago and have been breaking it in. The bike is an import from the USA (I live in the UK) so I’m pretty sure the stock jetting is no good for my location (no more than 300ft above sea level).

Where others have reported a hesitation when throttling it from low rpm my wr just dies, even after warming up for 5 minutes it still dies and requires choke to start again.

When its been ran for a while it doesn’t die as easily but has done.

Is this problem the same problem others are getting with “hesitation” only a bit more extreme or is it a completely different problem?

Would the jd jetting kit and r&d power pump aid in solving this problem?

Thanks for any help anyone can give me.

Hi guys, I’ve just bought a 2009 WR450 two weeks ago and have been breaking it in. The bike is an import from the USA (I live in the UK) so I’m pretty sure the stock jetting is no good for my location (no more than 300ft above sea level).

Where others have reported a hesitation when throttling it from low rpm my wr just dies, even after warming up for 5 minutes it still dies and requires choke to start again.

When its been ran for a while it doesn’t die as easily but has done.

Is this problem the same problem others are getting with “hesitation” only a bit more extreme or is it a completely different problem?

Would the jd jetting kit and r&d power pump aid in solving this problem?

Thanks for any help anyone can give me.

It does sound like the jetting is way off for your location. I wouldn't spend the money on a jd kit or power pump, it's just a waste of money. Do some research on the jetting database thread for this forum, you'll find plenty of real world examples of what jetting specs people are using at different locations. The best way to go about it is to de-restrict your bike(see the mods sticky thread for all the info), and get yourself a yz450f needle, throttle stop, and some pilot/main jets, it would help to get a fuel screw too. Way cheaper that way.

Well said Eric.

Your pilot jet could be clogged with dirt(replace), try a new spark plug(irodium), don't try cleaning it! Do the mod's, yz needle(ais kit), pipe it and look at the jetting thread and pic up a few various jets!

Hi guys, I’ve just bought a 2009 WR450 two weeks ago and have been breaking it in. The bike is an import from the USA (I live in the UK) so I’m pretty sure the stock jetting is no good for my location (no more than 300ft above sea level).

Where others have reported a hesitation when throttling it from low rpm my wr just dies, even after warming up for 5 minutes it still dies and requires choke to start again.

When its been ran for a while it doesn’t die as easily but has done.

Is this problem the same problem others are getting with “hesitation” only a bit more extreme or is it a completely different problem?

Would the jd jetting kit and r&d power pump aid in solving this problem?

Thanks for any help anyone can give me.

I'd start with comparing the jets in it to the jets found in a UK model. Figure out which are different, and order the UK spec replacements. On previous models i have worked on, they only required the odd jet changing in order to behave here in the UK.

Also, i presume it has all the usual restrictions that come with the US bikes? If so, remove them and then concentrate on the jetting.

My WRF450 is an 09 model as well, bought it a few months ago.

Standard jetting in Europe is:

Main jet : #160

Pilot jet #48

Jet needle : GDDUQ

Jet needle groove : 4

Leak jet #60

Pilot screw: 2 turns out

My bike had the mods done by the dealer to have full power, and had the stutter problem apparently most WRF's suffer from. But it never stalled and when driving off-road the stutter was never a problem.

Mod's done on a "European" bike :

-Throttle stop changed

-Adapted jetting

-Air Induction system removed

-Changed the exhaust pipe (in Europe the bikes are sold with a catalyst exhaust pipe - sticks out and breaks anyway the first time you fall with the bike)

-Don't know about the grey wire...

The dealer did change the settings by moving one jet needle groove lower to 5, and changing the pilot jet (don't know what they put in). As I live in Belgium, the UK shouldn't be that much different (same climate, same altitude, unless you live in the scottish highlands :banana: )

Results were much better, with still a light stutter at cruising speed.

The bike now has 700 km and the stutter is gone. I guess a good break-in helped a lot.

Do check your idle speed, maybe that's off ?

Right now I am not riding anymore, so I can't tell you how it evolves. I had a "whiskey throttle" last week, and went airborn. Broke my right collar bone :banana: So I'm out for 2-3 months. :busted::thumbsup:

But hey, no worries, the bike is fine ! :banana:

Who said these bikes aren't strong ?

i have a usa 2009 and ride it in the uk no pbobs atall

mayba a problem petrol/sparks

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