Please Help

[Badgadjit1]

I have been battling to get my bike running right (1999 YZ 250) for the last month or so. I have replaced my reeds with a Boyesen Rad Valve, I put on a PC Shorty R304 Silencer, jetted it until it made my head spin.

Carb Settings:
Pilot - Stock 50, I have a 45 in there
Needle - Stock 3rd Pos, I have in the 1st Pos (highest clip Pos)
Main - Stock 172, I have a 178

Two weeks ago I went racing and it was bogging from zero to half throttle so I took it as a rich setting, and it was blowing smoke so i dropped the pilot form a 48 to a 45. It ran slightly better.

This weekend I practiced in the morning it would again bog through zero to mid throttle like it was a rich setting again. So i raised the clip to lean it out more, i didn't have any more jets so this is all i could do. I took it for a test run in the pits and it seemed to run fine from zero to full throttle. Raced it and it was right back to the way it was in practice. Just bogging real bad zero to mid again.

I talk to somebody, and showed my plug, my plug looks pretty close to good (the chocolate brown color everyone speaks of) so he told me i probably have something stuck in my pilot, so i once again tore my bike apart, my carb was FULL of dirt, i looked in my airbox boot and it had wet dirt in it. not sure if it was oil or what, with all the dirt inside there. I thought that was kinda odd, so i took that all apart and cleaned it out really really good, and clean out my carb completly. I thought this would have fixed my problem. I got up for the second moto and i got it on the gate and reved it until i got a nice crisp sound not bogging. Took off okay and then about the second turn, back to bogging. This time is would bog from zero to mid and when i would land hard on a jump.

I haven't opened it up again to see if theres more dirt in it, but i have seen it in there before and had to clean it out. Could this be my problem? (i don't mean the dirt i mean the air leak or how ever that dirt is getting in there) I'm going to silicone around the gasket of the boot, I feel like i'm leaning it out way to much. I do have an extremely slow drip out of the crankcase.

Sorry for the long post, i just don't know what to do anymore, i have no power in the bike and i cant clear jumps and not getting good starts.

Thanks in advance.

 

[MikeT]

I would clean out your fuel tank, air box, air box boot, air filter, carb and then go back to the stock carb settings. The clip position needs to be either in the middle or one position up or down from there. IMO if you move it farther out than that you need another jet. Also, when you change jets just do one thing at a time. If you don't then you won't know which change made the effect you are experiencing.

 

[motogps]

I would set everything back to stock clean it so you can eat off it and do a leakdown test.

 

[Badgadjit1]

i read in eric gore's carb info about that test. how do you do it? and is there any cleaners i should or shouldn't be using? carb sprays, i use just normal carb cleaner from auto zone. or pj1 cleaner. and how should i clean out my fuel tank i use fresh gas every race, should i empty the fuel out and flush with water?

and when i clean my carb i take out the jets and spray all the holes in the carb and clean the jets, is there more to it?

 

[Badgadjit1]

i found this

http://www.dirtrider.net/forums3/showthread.php?t=87952&page=1&pp=10&highlight=leakdown

that work?

how will i know where the leak is internaly? is there any prep work with the motor before you do the test? drain oil or anything?

 

[j32]

do you need to keep adding oil to the crank case? it might be a oil seal leaking ,or a center gasket leak,but clean everything!!!!

 

[Badgadjit1]

going to clean everything, check my coil and do a pressure leakdown test today. I have a small leak out of the crank case i think, i'll be sure of where today

 

[Badgadjit1]

k just did my leak test and i'm not holding pressure AT ALL air is blwing out of my cover that is on the magneto side and out of the crankcase......could this be the entire problem or just part of it?

 

[motogps]

I would say that it is the main problem. Those crank seals are real easy to get to on a Honda, not sure on a yz.

 

[daniel 40]

When u get it back together, and if u still have jetting/ prombles call the Boyesen tech support line 1-800-441-1177/ they can tell u what to do from there.

 

[Badgadjit1]

Thanks guys, its comming completly apart tuesday. Have to wait for all my new parts to come in. Hopefully this is it!