250-500cc 2009 WR300 Hard to Start

[RobNewy]

My 300 has been a mongrel to start since the day I brought it new 7 weeks ago. It takes 10-15 kicks when cold or hot.
The bike only has 123 kms on it now, so I'm ruling out compression or reeds. When it is going, it is a rocket ship!!
There is a small hesitation at about 1/8 throttle in the higher gears.
My jetting is:
#420 Main jet
#40 Pilot Jet
#80 Start Jet
#4 Slide
Air Screw 2 turns out.
CLip is in the standard spot, I'm assuming.
Also the idle screw, I have had to wind in until it's flush with the locknut.
Seems pretty excessive
I have had the carb apart, and blown the jets out with contact cleaner, but still hard to start.
I am at sea level to about 600'
Any advice would be great
Thanks

 

[Norman Foley]

Try a 45 pilot and check your air screw position. If you have starting and 0-1/8th throttle problems, this is where I would start. Pilot can be changed through float bowl drain on new style TMX.

 

[RobNewy]

Cheers Norman.
I might grab some jets tomorrow and have a play.

 

[Rob578]

Mine has been hard to start since Day 1. I've had mine about 5 weeks now. My final jetting before I tossed the Mikuni was 420MJ Clp in #1 37.5 PJ. It was still too rich but I'm running VP 110 and Motul @ 50:1.

With the PWK mostly dialed in it usually starts with one kick, no throttle and the choke on. But when it's hot like stalling it in the big rock piles it is a bear to start. doesn't help that I'm tired and only giving it a half-a** kick.

It does seem to be getting better, maybe I'm just getting accustomed to the bizarro kick starter... start perfecting the stand beside the bike and kick with your left leg.

The KDX spoiled me...... all I had to do was look at the kick starter and it would crank

 

[motosapiens]

you guys may have a totally different needle than the us models, but ours come jetted very rich, and can be difficult to start due to that. lowering the needle and going to a smaller pilot jet helped mine.

however, it seemed to me that the stock mikuni carb just doesn't handle starting all that well. even when i got it jetted right (or borderline lean) it would balky hot starting, esp in warm or humid weather, and acted like it was way too rich at 0 throttle. the keihin carb from motosportz fixed that for me. starts easier now hot or cold, and requires less fussing with the airscrew to make it behave.

even with everything perfect, it's definitely harder to start than my wussy little 200xcw. as a result, i choose the 200 for trail work days (packing a saw), course marking, riding with slow people, or other situations that require lots of stopping and starting.

 

[BikePilot]

My WXC250 had way too much compression when I got it (used, so don't know if that was factory or if someone had screwed it up along the way) and could be quite hard to start. Once I installed the proper thickness base gaskets it started and ran much better. If the 300 uses the same system where base gasket thickenesses are varied to achieve correct deck height maybe husqvarna accidentally slipped too-thin a gasket in place. just a thought. Once I had my WXC dialed in my ~115 lbs sister could start and ride the bike just fine.

good luck!

 

[letitsnow]

My WR250 has 200 lbs of compression and would probably start upside down with one kick. Something is wrong...

 

[MOTORHEAD]

I think the low compression 300's are harder to start than the 250's anyway, but a richer pilot seems to help.

 

[RobNewy]

Thanks guys
I've been hearing good things about the 42.5 pilot so I might grab a couple each side of that today.
I will let yous know what I come up with

 

[RobNewy]

I have just been having a bit of a look at Motosportz and saw the PWK for a really nice price.
Do you have to do any mods to anything to get it to fit.
And also, do they ship international?
Cheers

 

[Johnnymannen]

I have just been having a bit of a look at Motosportz and saw the PWK for a really nice price.
Do you have to do any mods to anything to get it to fit.
And also, do they ship international?
Cheers

Hello! No mods are required. It´s a tighter fit in the intake boot, and it pushes the intake boot back a bit, but that´s no problem. And yes, they ship international! I got mine quick to Sweden. Good and fast service and a big improvement! I think i can start my 300 with my hand if i want to! Buy it!

Johnny

 

[RobNewy]

Cheers Johnny.
I will see if I can get the TMX going first.
Just on $600 here for a PWK in Australia!

 

[RobNewy]

Well, I lowered the clip one position, it's now in the middle, and it fires first or second kick, hot or cold.
Not sure if that got rid of the small hesitation at low throttle, because the wether is pretty ordinary.
Thanks for the advice!

 

[Johnnymannen]

Well, I lowered the clip one position, it's now in the middle, and it fires first or second kick, hot or cold.
Not sure if that got rid of the small hesitation at low throttle, because the wether is pretty ordinary.
Thanks for the advice!

Ok, good! Do you know which needle you have? Mine started well with the Mikuni too after i found then right jetting, but no matter how well you jet the Mikuni, the PWK is still a big improvement! Stronger bottom, easier rejetting, and not so sensitive as the Mikuni. BTW, strange that you have a #4 slide. I have #7 in mine, but maybe it´s different here in Europe

Johnny

 

[RobNewy]

I'm not real sure of the needle. I know it is the stock one for Australia.
I had it out today, so I should have written it down
Not sure what a #7 slide would do here, but I have heard that the #5 is excellent for here, but that is a pretty big expense, that I don't need just yet.
The PWK may still be an option. I don't really do much drastic elevation changes, but temperature is definantly a factor. It will go from 45C and 85% humidity in summer, down to 5C and 20% humidity in winter, so it is a dramatic change.
Do you think the PWK would be less fiddly?
Cheers

 

[Johnnymannen]

Ok, i guess there is different slides in different countries. Yes, the PWK is not so sensitive as the TMX. You will get an easier starting bike with a stronger bottom too. It´s actually a quite big difference in bottom end power delivery. And when you want to do any changes to your jetting you just twist the carb in the boot and unscrew the top of the carb and lift out the throttle. I change needle in 3 minutes maximum.

Johnny

 

[2stroked]

The pilot sounds to rich, I only have a 250 but with the JD kit I have a 32.5 pilot and my bike runs good everywhere, I can pull right off idle and start out in 2nd most of the time unless i'm on a hill with stock gearing.
The TMX seems to be finicky with jetting but I can't see my bike running much better, more power everywhere than I need.
I was running a 30 pilot with out the JD kit and some guys were running 27.5 with good results, the 300 couldn't be that much richer for jetting.
The JD kit is the same for both bikes, only comes with a 32.5 pilot, new needle jet, red/blue needles and some main jets

 

[buzuki]

im running

#4 slide
# 430 main
# 40 pilot
3rd clip on needle
1 and 3/4 turns on screw

Tested today and seems to be almost spot on

 

[firecrotch]

I cant get my 300 to start for cr@p unless I absolutely have piston tdc. Then it fires right up everytime. Probably not your problem Just thought I would mention.

 

[fletchman45]

My buddy who is a wussy and a c-rider and a small guy gets his 09 300 started ALWAYS on the 1st or 2nd kick with stock jetting. HMMM ... I used to ride wr 250's all the time and what I found was kick it like a man and they would start on 1st kick. Kick it like a tired wuss and your lookingt at 5 or 6. Wait, buy a 125 pass your buddy aqnd then give him crap!! Just kidding a 300 would work well in some places. Good luck!