CR250R: Stalled, Won't Restart

[BBowski66]

I recently bought a 97' CR250. Bike was recently rebuilt with a Wiseco piston, ring, etc. Has an FMF Knarly pipe, and FMF silencer.

I was riding today (only the second ride) in a fairly moderate rain and the bike stalled. It almost got ugly as the rear tire locked up and the tail end of the bike went into a tail slide. Pulled the clutch, got stopped, made sure fuel was on, touched jug and radiator with bare hand and they were hardly hot (I'd only been riding about 5-6 minutes).

The damn thing would not restart and I pushed it home 3 miles. Tried disconnecting the kill switch, pulled the tank and checked electrical due to all of the water, pulled the plug and I am getting spark (plug is dark grey-brown), pulled the carb and disassembled (all vents clear, no contamination in bowl, air checked all passages, found O-ring for air screw to idle jet misinstalled and torn). Checked reeds, closed and opening slightly while kicking, pulled inspection cap from power valve and it is sitting solid at 'L' (won't move with a flat blade, not sure if it should.)

Put it all back together and started kicking again. After a while I got 3-4 backfires from the pipe (silencer off at this point) with a decent blue flame, but wouldn't start....

HELP? :think:

 

[76GMC1500]

Is this your first time running a 2-stroke? If it's hard to start, the first thing is to put it in neutral. When you kick it, start with the throttle closed and roll it on a little bit as you do the kick. This usually gets it going. When it's cold you usually use the choke and don't touch the throttle, like a 4-stroke. But it it pops a little but wont fire up, sometimes I do the roll on the gas thing as I kick and it usually goes in 1 or 2 more tries.

 

[BBowski66]

Any idea why it just up and quit? I was on it in 5th, probably doing about 50-55mph?

 

[whenfoxforks-ruled]

Check the ignition rotor key. Make sure you have all that do ring out.

 

[BBowski66]

Check the ignition rotor key. Make sure you have all that do ring out.

I don't follow? I'm getting spark, where is the key located?

 

[IndyMX]

I don't follow? I'm getting spark, where is the key located?

he's talking about the key in the shaft on the stator..

It's what keeps the ignition on the crank shaft from spinning.

 

[BBowski66]

So if I have spark, this has to be okay. Right?

 

[IndyMX]

So if I have spark, this has to be okay. Right?

No.

You may have spark that's 180 degrees out from TDC

 

[BBowski66]

I see, why would it have happened while riding though? How do I check it?

 

[whenfoxforks-ruled]

Pull the nut off and check

 

[IndyMX]

I see, why would it have happened while riding though? How do I check it?

Sh!t happens?

 

[BBowski66]

What nut? behind left or right side cover?

 

[whenfoxforks-ruled]

Left

 

[BBowski66]

Why would this have sheared in 5th gear while hauling ass down the road though?

 

[BBowski66]

If the key sheared, would the rear tire just lock up and go into a skid?

 

[IndyMX]

Why would this have sheared in 5th gear while hauling ass down the road though?

Because things usually break when they are under stress, not when sitting still in your garage.

 

[DLHamblin]

If the key sheared, would the rear tire just lock up and go into a skid?

Are you sure you didn't seize it up? That would account for the lock up. Once cooled it might kick over (might even start for a bit).

If you take the spark plug out and push the kick started through with your hand does it move smoothly (no grating or excessive tightness).

If everything else checks out you might want to pull the cylinder and have a look.

 

[BBowski66]

Yeah, the thing kicked fine right when it died. It died, I stopped, and kicked. No evidence of a seizure. With the plug out the thing spins great by hand.

Do I need all new gaskets if I pull the cylinder? Also, could I just take the pipe off and have a look?

 

[berlinetta]

just curious, have you checked the ignition key?

 

[DLHamblin]

Yeah, the thing kicked fine right when it died. It died, I stopped, and kicked. No evidence of a seizure. With the plug out the thing spins great by hand.

Do I need all new gaskets if I pull the cylinder? Also, could I just take the pipe off and have a look?

Yes, depending on what you see decide if further tear-down is needed.

The fact it locked up the rear wheel, but would easily kick over is puzzling.

 

[BBowski66]

Yeah, only thing I can think is that it was pouring rain, the road was slick, and I was in 5th gear. If any gear were going to lock it, I think it would be 5th.??

 

[whenfoxforks-ruled]

If that key sheared it would kill the engine and will not start

 

[IndyMX]

What was the temp outside when this happened?

Could it be that the engine cold seized?

Perhaps you didn't let it warm up enough before you took off?

 

[BBowski66]

What was the temp outside when this happened?

Could it be that the engine cold seized?

Perhaps you didn't let it warm up enough before you took off?

45 or so...how exactly can you cold seize it?

 

[BBowski66]

If that key sheared it would kill the engine and will not start

Yeah, but would it lock the rear tire?