250-500cc WR300 2011 wont start

Tried everything....

Carb been apart several times, cleaned, setup etc.

Checked all electronic connections and seem to be good.

Bike has done 50hrs.

Repalced reeds/inlet manifold.

I have good spark but get the feeling it is almost intermittent? Kick starter every now and then tries to throw you over the bars which I have never experienced in the past.

Im wondering if its sheared the flywheel key and thrown the timing out? Dont have a flywheel puller to check it.

Story was bike was leant to a mate that rides on the pipe like its a 125. Halfway through a ride he pulled over for a rest then it wouldn't kick start only push started. He tried to get it going checking various plugs and clean/re setting carb then gave it back to me. I have tried the same but to no avail.

Plug is drenched so plenty of Fuel. Visible strong spark but could be out of time.

If the bike actually did start (as it has been very close) would it run good at high RPM but die at low rpm due to timing, or would it just not run at all?

Need your help guys!

Stu

Sounds like it fired a piston or has a compression leak. Might pull the head and take a look.

Did he go through any deep water? I had a very similar experience after a creek crossing.

wasn't there a thread on here about the ignition being a problem on these, is this the year that was the issue

Dumb question..
Did you replace the plug with a clean one? I think the bike wants to fire if its kicking back at you.

Another thing..
If you know anything about shooting a rifle or even throwing a punch lol...Follow thru is sooo important
Its the same thing with the kicker. Follow thru with the kick or it will hurt haha

if you have to push start the piston or rings are done

not sure if they are the same but before my 360 got a new ignition it was impossible to start, I would bump start it when I was worn out from kicking

Head and barrel straight to after taking it apart...




Everything looks pretty nice so far. Barrel off next...oh and for those in the USA...im in South Australia and it is 45 degrees Celsius today and will be 46 tomorrow. Work that out on the imperial scale.

Humidity will be at about 15%...love the desert!

Stu

I see a "B" stamped on the piston, is that the size? Are their like "A", "B", or "C" pistons and such for the 300?

Good question.

Something I am sure anyone but us can probably answer....

Stu

I can usually start the thing, standing next to the forks, facing the back of the bike....with my left leg so thats not the problem.

Stu

yes there are 4 sizes of pistons.
i think if your woodruff key has sheared you may not need the flywheel puller. i would check and see as its that as it would be a quick fix oh and see if the back plate of the stator is tight as if thats moved your timing may be detonation and causing the kick back.
was there any oil in the stator cover?

Shot in the dark but had a similiar problem on my 125. When I ground the spark plug to the head I got good spark. When it was in the bike it was arcing. Took 3 months to figure it out.

I found out by arcing from the boot to plug with a screwdriver and it started instantly. Give it a shot, may simply be the boot.

Also check under the gas tank where the kill switch can rub on the frame. This happened to me on my 2011.

its a faulty ignition system.you will find the spark is intermitent & weak

G'day, My WR 300 will not start with the head light on.. Check the head light is off.
Spent 3/4 hour one day with just kick backs ouch! Light off 2 kicks latter, big grin lots of smoke.

I have had similar experience and others have to...the wires down bu the coil where it bends up chaff thru and ground out on the frame. worth a check. unplug it and pull out so you can visually verify it's not grounding out.

but if you have to roll start down a big hill when engine hot with full choke & throttle on a near new 2012 300 with fresh fuel,clean plug etc you know you have the biggest lemon on the lemon tree.any one with a ducati ignition fitted,it should be the 1st thing checked with problems like starting,kickback,stopping or stalling for no reason & DETONATION,SEIZURES,ENGINE FAILURES.push hard to get a warranty repair & replacement of complete ignition system.pity Husky changed from Kokusan to made in INDIA rubbish ignition as overall it's a very good bush bike.

My 2012 wr300 bogged out mid race about 35 miles in. Runs like its super rich(first 1/8th of the throttle it's really crisp but then when you get on the top end it just flattens waaaaay out. Almost like the power valve isn't connected properly, but it is haha.) but jetting is perfect and I run 50:1. I'm starting to lean towards an ignition issue but don't really have any idea where to start with that one. When I made it to the pits after about 10 miles of not being able to get above about 30mph I noticed my ignition had snapped off the frame and was dangling on the head. Didn't see any melted wires or rubbing if any sorts. I've been scratching my head over it the past week and even bought a new keihi carb because I thought the float was acting up once again on the mikuni. Please please help me out! Haha I've got the itch to go racing again real soon but can't figure this one out