250 The 1999 YZ250

Trfsrfr

Trfsrfr

Mihylo33:
I thought you were there already?
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I might be, I have to recheck. I got 4 bikes apart right now, and sometimes I forget to write things down. Im pretty sure the PJ is a 50 cuz I have a 48 in my carb parts box.
It's been too cold in the garage recently so I've been reluctant to go out there, but its warming now up so I'm gonna go play with the YZ and the KX. Supposed to be 66 today, which is tolerable.

NOW everything is to PC specs, 168, 48, 6.5mm.

If everything is in spec, float, jets, jet needle, ratio, etc, and I still cant get this thing to run cleaner, does that mean I'm looking at a right side crank seal?

And, I just looked at my manual and it's for a 98. What are the chances the float specs I'm looking at are different for my 99???
 
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Mihylo33

Mihylo33

Trfsrfr:
I might be, I have to recheck. I got 4 bikes apart right now, and sometimes I forget to write things down. Im pretty sure the PJ is a 50 cuz I have a 48 in my carb parts box.
It's been too cold in the garage recently so I've been reluctant to go out there, but its warming now up so I'm gonna go play with the YZ and the KX. Supposed to be 66 today, which is tolerable.

NOW everything is to PC specs, 168, 48, 6.5mm.

If everything is in spec, float, jets, jet needle, ratio, etc, and I still cant get this thing to run cleaner, does that mean I'm looking at a right side crank seal?

And, I just looked at my manual and it's for a 98. What are the chances the float specs I'm looking at are different for my 99???
Click to expand...

Have you tried a hotter plug? If it were a crank seal you would now.
 
Trfsrfr

Trfsrfr

Mihylo33:
Also...... just a thought, are you running straight pump?
If you mix 50/50 with a premium pump and some 100ll you will get a better result.
Click to expand...
I'm running premium pump gas and I think its 91 octane. Pretty sure that is all we have here. I can run out to the local dropzone and get some 100ll though...maybe I'll try that as well.
Is that octane boost stuff worth a darn?
 
Mihylo33

Mihylo33

Trfsrfr:
I'm running premium pump gas and I think its 91 octane. Pretty sure that is all we have here. I can run out to the local dropzone and get some 100ll though...maybe I'll try that as well.
Is that octane boost stuff worth a darn?
Click to expand...


Booster. No. 100ll definitely helps. VP makes a great race gas. I use c12 but they make a 94 octane which is good for both stock and worked motors.
 
Trfsrfr

Trfsrfr

Started the bike up again today after repairs, choke on, and once again fouled the plug, a brand new plug.

How does one unfoul a plug, cuz I got a basket full of them...?
 
Trfsrfr

Trfsrfr

The guy that taught me how to be a mechanic when I was 15, and gave me the ability to make a living for 20 years, RIP, once showed me a trick that he used to use that involved an oxy/acetylene torch, but I've never had any success with it...
 
Mihylo33

Mihylo33

Trfsrfr:
Started the bike up again today after repairs, choke on, and once again fouled the plug, a brand new plug.

How does one unfoul a plug, cuz I got a basket full of them...?
Click to expand...

Are there any markings on the head or cylinder? Something that doesn’t look like it belongs?
While you are at it. Remove the coil and sand the frame contact points and the bolts. Do the same to the magneto.
 
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