CR250R: Stalled, Won't Restart

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BBowski66

Member

Dec 21, 2006

13

0

• Dec 21, 2006

• #1

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:

 

7

76GMC1500

Uhhh...

Oct 19, 2006

2,142

1

• Dec 21, 2006

• #2

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.

 

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BBowski66

Member

Dec 21, 2006

13

0

• Dec 21, 2006

• Thread starter
• #3

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

 

whenfoxforks-ruled

Old MX Racer

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Oct 19, 2006

8,129

2

Merrillville,Indiana

• Dec 21, 2006

• #4

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

 

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BBowski66

Member

Dec 21, 2006

13

0

• Dec 21, 2006

• Thread starter
• #5

whenfoxforks-ruled said:

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

Click to expand...

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

 

IndyMX

Crash Test Dummy

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Jul 18, 2006

5,548

2

Amo, IN

• Dec 21, 2006

• #6

BBowski66 said:

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

Click to expand...

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

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

 

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BBowski66

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Dec 21, 2006

13

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• Dec 21, 2006

• Thread starter
• #7

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

 

IndyMX

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Jul 18, 2006

5,548

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Amo, IN

• Dec 21, 2006

• #8

BBowski66 said:

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

Click to expand...

No.

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

 

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BBowski66

Member

Dec 21, 2006

13

0

• Dec 21, 2006

• Thread starter
• #9

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

 

whenfoxforks-ruled

Old MX Racer

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Oct 19, 2006

8,129

2

Merrillville,Indiana

• Dec 21, 2006

• #10

Pull the nut off and check

 

IndyMX

Crash Test Dummy

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Jul 18, 2006

5,548

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Amo, IN

• Dec 21, 2006

• #11

BBowski66 said:

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

Click to expand...

Sh!t happens?

 

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BBowski66

Member

Dec 21, 2006

13

0

• Dec 21, 2006

• Thread starter
• #12

What nut? behind left or right side cover?

 

whenfoxforks-ruled

Old MX Racer

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Oct 19, 2006

8,129

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Merrillville,Indiana

• Dec 21, 2006

• #13

Left

 

B

BBowski66

Member

Dec 21, 2006

13

0

• Dec 21, 2006

• Thread starter
• #14

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

 

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BBowski66

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Dec 21, 2006

13

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• Dec 21, 2006

• Thread starter
• #15

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

 

IndyMX

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Jul 18, 2006

5,548

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Amo, IN

• Dec 21, 2006

• #16

BBowski66 said:

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

Click to expand...

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

 

D

DLHamblin

Member

May 27, 2005

268

0

• Dec 22, 2006

• #17

BBowski66 said:

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

Click to expand...

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.

 

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BBowski66

Member

Dec 21, 2006

13

0

• Dec 22, 2006

• Thread starter
• #18

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?

 

B

berlinetta

Member

Dec 16, 2006

56

0

• Dec 22, 2006

• #19

just curious, have you checked the ignition key?

 

D

DLHamblin

Member

May 27, 2005

268

0

• Dec 22, 2006

• #20

BBowski66 said:

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?

Click to expand...

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.

 

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BBowski66

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Dec 21, 2006

13

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• Dec 22, 2006

• Thread starter
• #21

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

Old MX Racer

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Oct 19, 2006

8,129

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Merrillville,Indiana

• Dec 22, 2006

• #22

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

 

IndyMX

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Jul 18, 2006

5,548

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Amo, IN

• Dec 22, 2006

• #23

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?

 

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BBowski66

Member

Dec 21, 2006

13

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• Dec 22, 2006

• Thread starter
• #24

IndyYZ85 said:

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?

Click to expand...

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

 

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BBowski66

Member

Dec 21, 2006

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• Dec 22, 2006

• Thread starter
• #25

whenfoxforks-ruled said:

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

Click to expand...

Yeah, but would it lock the rear tire?