85 kx500 won't fire up after top end rebuild.

[GMC]

Pulled the stator casing then the flywheel and couldn't believe it,the woodruff key(flywheel key) had sheared in two,

I’ve had that happen before too, they can shear on the first fire.
I had only just checked the stator was on properly so it wasn’t on my high suspicion list.

[Lozza]

Pulled the stator casing then the flywheel and couldn't believe it,the woodruff key(flywheel key) had sheared in two,half of it in the flywheel and half of it in the crank shaft!!Strange to as i've always got a good strong spark so wasn't even thinking about electrics.This doesn't solve the fact though fuel isn't getting drawn up to the spark plug though from the reeds!

You might have got a spark but it was at the wrong time.

[floberts]

Be careful doing a tow start, or I should say, be careful who you choose to tow start you.

I had a "friend" tow start me once. Finally the RM fired up but the driver didn't hear it start (or wasn't taking notice) so i gassed it up a bit took my left hand off the bars to wave to him to stop. Dickhead kept going and when the slack was taken back up in the tow rope I foolishly was still waving frantically. Anyway the bars got jerked out of my hands, I went down, the bike went down my "mate" kept driving and somehow I had the bike pulled over the top of me. I wasn't happy. The bars and a lever broke and that was the last straw, I sold the bike after that (had also broken an ankle and a collar bone in the last 6 months.

It is funny to look back at now. I have some nice foot peg scars on my shin to remind me of the incident. And I cannot completely blame my friend.

Eventually the bike bug got the better of me again and I bought the PE 3 years ago. So a happy ending of sorts.

[matcho mick]

towstart & with a crankcase full of fuel,bending the rod with hydraulic lockups possible too,hmmm no comp ,
ps mate was towing me home ,20ft rope,he went round the corner & accelerated as i was still coming up to it,oops, apex over base sideways

[rumpelstiltskin]

Be careful doing a tow start, or I should say, be careful who you choose to tow start you.

I had a "friend" tow start me once. Finally the RM fired up but the driver didn't hear it start (or wasn't taking notice) so i gassed it up a bit took my left hand off the bars to wave to him to stop. Dickhead kept going and when the slack was taken back up in the tow rope I foolishly was still waving frantically. Anyway the bars got jerked out of my hands, I went down, the bike went down my "mate" kept driving and somehow I had the bike pulled over the top of me. I wasn't happy. The bars and a lever broke and that was the last straw, I sold the bike after that (had also broken an ankle and a collar bone in the last 6 months.

It is funny to look back at now. I have some nice foot peg scars on my shin to remind me of the incident. And I cannot completely blame my friend.

Eventually the bike bug got the better of me again and I bought the PE 3 years ago. So a happy ending of sorts.

Seen the guy up the road do that,just as he bumped it the bike just got pulled onto it's side and was was dragged along behind the car!

[pancho]

 Back in the olden days when I was game enough to let a mate tow my road bike, some even older, wiser person told me to wrap the rope one turn 'round the handlebars close as possible to the middle and then clamp the end of the rope on the left side grip [holding it with your hand,] then you can release it easily if needs be.
 best idea is dont be towed. cheers pancho

[Curly3]

Personally I wouldn't tow start, full stop.
To much fuel & rotations happening before ignition.
If it won't start off the kicker or the average push start, summpin aint rght.

[rumpelstiltskin]

Well,got the woodruff/flywheel key fitted and still wont fire up,spark plug still not getting fuel,im convinced about that.If the reeds are wet and with the manifold off i can see the reeds are moving so fuel must be getting there,and compression is good!Im just on the verge of getting rid of it,it's getting on my nerves!I've spent a fortune restoring it and it can't even do me the pleasure of firing up,the sod!  :cry:

[LWC82PE]

Ok you probably checked this but check again
- air leaks at manifold
- ignition timing
- How fresh is your fuel? Is it as fresh as you think it is?
- fuel tap issues
- kill switch issues
- tank cap issues (blocked vent)
- carby - correct settings and jets. Completly strip it and blow out all orifices with compressed air. Check for blocked vent tubes etc
or loose parts.
- pour some petrol in the plug hole or spray some instant starting fluid in. That should start it if its gonna star or at least get it firing a bit.
- Are you sure you are getting a good spark? If not check plug cap and plug lead for faulty connections and get one of those spark testers that you can test if the amount of spark is actually enough and not just enough to make the plug spark outside the engine. Dont just assume that if the plug sparks that it is a good enough spark for ignition. I have had weak flywheels/rotors that will produce a spark at the plug but have lost enough magnetism for the spark to be weak enough to be not enough to fire it up.
- has it got a power valve? Could there be issues with the set up of that?
- have you fitted new crank seals, if so are they in the right way?

There are only so many things it can be, it can not be anymore easier than a 2 stroke like this. It will be obvious when you find it. I have heaps of different problems like this over the years, eventually you will find it after thinking you have checked everything and you may find out it was the thing you least expected.

[PEZBerq]

Some Husky 500's including mine require a shot of raw fuel down the spark plug before they will start when stone cold  .  Just cant seem to get enough fuel in to the cylinder by kicking it over.  Once it starts that way it is OK for the rest of the day  .

No way would it start otherwise (being an auto push starting is out of the question  . 

Other people have no trouble however with their big bore H and dont need to do this ritual - go figure  . Anyway worth a shot on the big KX. Use a length of small clear tubing to dip into the fuel and drop a few mls (say 10 - 20mm of fuel in the tube) down the spark plug hole being careful not to knock any dirt in!

Good luck I know how frustrating it is.