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6767
Joined
8/30/2008
Location
Stockholm
SE
DrSweden
8/22/2016 3:49pm
8/22/2016 3:49pm
Bike runs great when it rides: on idle, half or full gas. It is crisp, no misfire or bogs, can run full motos. But I can't kick start it because it either kills my foot, or it breaks the kick axle (has happened twice). I have owned many bikes (another YZ250), no problem with my kick skills.
Imagine kicking it and halfway through, it hits back hard in the soil of the foot, to the degree that the kick axle breaks. I have rotated the stator plate in all possible ways. Right now full retarded. It is so mellow its mad. If I hold down the kill switch, or pull the spark plug I can kick it like a normal two stroke (but it doesn't fire up of course). I have OEM piston, cylinder and head. Hotrod crank. Bought a new CDI, new reeds, tested a new cylinder head nothing changed.
Previous owner repaired the stator, one coil was bad. He put new wirings in it.
I had high hopes in a new CDI, but noooooo. It's like I get an extra spark before TDC when I kick it, but as it fires up, no issues.
It's a bitch to jump start it as well. This back fire seems to add extra compression, makes the back wheel lock, even on tarmac. I need to really jump on the saddle in third.
I have an extra coil and spark cap. Also extra wiring. Well of course test that...
Imagine kicking it and halfway through, it hits back hard in the soil of the foot, to the degree that the kick axle breaks. I have rotated the stator plate in all possible ways. Right now full retarded. It is so mellow its mad. If I hold down the kill switch, or pull the spark plug I can kick it like a normal two stroke (but it doesn't fire up of course). I have OEM piston, cylinder and head. Hotrod crank. Bought a new CDI, new reeds, tested a new cylinder head nothing changed.
Previous owner repaired the stator, one coil was bad. He put new wirings in it.
I had high hopes in a new CDI, but noooooo. It's like I get an extra spark before TDC when I kick it, but as it fires up, no issues.
It's a bitch to jump start it as well. This back fire seems to add extra compression, makes the back wheel lock, even on tarmac. I need to really jump on the saddle in third.
I have an extra coil and spark cap. Also extra wiring. Well of course test that...
The squish thing I don't get? Would it end up with backfire if faulty?
Would a bad wired stator be able to give extra sparks?
Power valve, I have no idea? What would it do if it was faulty? Bikes runs great as soon as it fires up?
I have no idea about the crankshaft, previous owner bought it. But would another bikes crank even fit and make it run?
So strange...
The Shop
RE: Compression....100psi is very low, so the guage must be incorrect. At that pressure it should not even start.
RE: Stator....Yes a bad stator can do all sorts of strange things to the spark timing .
RE: Power valve....If dirty it can be sticking and not allowing full power.
RE: Kick back...Timing is not correct.
Paw Paw
220 PSI is in race has territory
Compression gauges do vary from gauge to gauge, but not that much
Picture you kick down, you get this extra spark before TDC, it kicks back, but you are already committed so bang in your foot, or kick axle breaks. While jump starting you get some serious tire marks on the asphalt, despite third gear. But as soon as you overcome this back firing, it starts right away.
So if I had a bulky kick shaft made of titanium, and a foot worthy an terminator, I would start, no problem.
Position of the stator,
Installed incorect, coil backwards, wire not insulated????????????
.004 is 1 degree retared
That thing kicked back so hard, I thought I had broken my foot / ankle. It had me on the ground for about 20 minutes. Reversed the wires to the correct positions, and all was fine.
Would bet it's an ignition problem.
It definitely sounds like ignition though.
Pit Row
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