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Discussion Starter · #1 ·
can anyone tell me why i have to run the choke half on?
i just put a hmf slip on and airbox lid off with stock filter my jetting is 175 main and a 45 pilot needle is in the stock position i ride in very cold weather when the bike warms up it boggs and dies when full throttle . but if i put the choke half on it runs good under full throttle.a 175 main cant be too big in 20 degree weather could it.? can anyone help me??
 
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Originally posted by 97banshee@Jan 31 2004, 05:24 PM
can anyone tell me why i have to run the choke half on?
i just put a hmf slip on and airbox lid off with stock filter my jetting is 175 main and a 45 pilot needle is in the stock position i ride in very cold weather when the bike warms up it boggs and dies when full throttle . but if i put the choke half on it runs good under full throttle.a 175 main cant be too big in 20 degree weather could it.? can anyone help me??
LEMME GET THIS STRAIT YOU PUT A 175 main and a 45 PILOT BUT U STILL HAVE THE STOCK NEEDLE ON THE 3RD CLIP! :wtf :eek

TRY CHANGING IT TO CLIP 5 OR 6 FOR NOW (YOU MUST GRING OFF THE END! TAPERED END!.)

BUT YOU WILL MOST LIKELY TRY TO GET THE YF NEEDLE! AND PUT IT ON CLIP 3 OR 4

:nono :eek
 

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Discussion Starter · #3 ·
ok so im fine with the clip postion just back off the air screw ? the air screw is in stock position too
 

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whats your elevation?the choke is actually an enrichener, so it sounds like a lean problem. move clip on needle to 5 position and dorp down to a 170 main. any way thats what id try. :O and if that doesnt work :ihit . :lol
 

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Originally posted by 97banshee@Jan 31 2004, 05:45 PM
i believe im sea level how can i be lean with a 175 main?
i think u are too rich but whatever
 

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Too rich?

No, too lean. When the weather is cold, typically it is under high barometric pressure conditions which means that the engine can take in more air. Also cold air is much denser and contains much more oxygen than warm air. Therefore, you have to go up about two clips on your needle, and maybe even one jet size to get it to run right in cold. I am running a 180 main right now to ride when it's cold, when it's warm out I run a 175. It's an easy fix. Good luck...

Maxx

P.S. I am running the stock needle in the 5th position
 

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Originally posted by Clutch123@Jan 31 2004, 05:33 PM

LEMME GET THIS STRAIT YOU PUT A 175 main and a 45 PILOT BUT U STILL HAVE THE STOCK NEEDLE ON THE 3RD CLIP! :wtf :eek

TRY CHANGING IT TO CLIP 5 OR 6 FOR NOW (YOU MUST GRING OFF THE END! TAPERED END!.)

BUT YOU WILL MOST LIKELY TRY TO GET THE YF NEEDLE! AND PUT IT ON CLIP 3 OR 4

:nono :eek
Easy there killa... You don't grind off the tapered end you grind off the flat end. If he grinds the tapered end off he is gonna have hella problems.


I say keeo the 175 main (that is pleanty). How does it start? If good keep the 45 pilot, set your mixture screw to 2 turns out to start, and you may need to go out to 2 1/2 - 2 1/2 turns out.

If you don't want to buy another needle trake the stocker out grind a little off the flat end, (a file will work) and then put it on clip 6 replace it and enjoy your new ride.

But to get the most out of it buy a YZ (NCVQ) needle and put it on the 3rd/4th clip.

I bet that you have some popping when you let off the throttle right?
 

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running in cold weather leans out the motor, need more fuel go to 4th/5th clip setting on needle. dont touch air/fuel mixture screw until you got the main, needle setting and pilot right. air/fuel mixture screw is an adjust at idle to 1/4 throttle
 
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Originally posted by Pahrump+Feb 1 2004, 08:20 AM--></span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Pahrump @ Feb 1 2004, 08:20 AM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin--Clutch123@Jan 31 2004, 05:33 PM

LEMME GET THIS STRAIT YOU PUT A 175 main and a 45 PILOT BUT U STILL HAVE THE STOCK NEEDLE ON THE 3RD CLIP! :wtf  :eek

TRY CHANGING IT TO CLIP 5 OR 6 FOR NOW (YOU MUST GRING OFF THE END! TAPERED END!.)

BUT YOU WILL MOST LIKELY TRY TO GET THE YF NEEDLE! AND PUT IT ON CLIP 3 OR 4

:nono  :eek
Easy there killa... You don't grind off the tapered end you grind off the flat end. If he grinds the tapered end off he is gonna have hella problems.


I say keeo the 175 main (that is pleanty). How does it start? If good keep the 45 pilot, set your mixture screw to 2 turns out to start, and you may need to go out to 2 1/2 - 2 1/2 turns out.

If you don't want to buy another needle trake the stocker out grind a little off the flat end, (a file will work) and then put it on clip 6 replace it and enjoy your new ride.

But to get the most out of it buy a YZ (NCVQ) needle and put it on the 3rd/4th clip.

I bet that you have some popping when you let off the throttle right? [/b][/quote]
bansheebc told me to grind off the tapered end. thank god i used my common sense! :lol i thought that was called the tapered end. ohh well!
 

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yea i'm having the same problem...choke half on when cold (40-) and fine when it warm (60+)...and it does pop when I let off ...so thats a lean condition? btw I have a 172 main and 45 pilot....also does anyone know what the difference between the long hex main jets (stock style) and the stubby jets with the slot for a flat head screwdriver? I went to the dealer and thats what they gave me...it worked but am wondering if there is a reason for the longer jets?
 

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yes, you are running lean. go up in main, and/or 4th/5th clip setting on the needle..... then run it.............gooodluck!!!!!!!!!!

the difference between the long hex main jets and the stubby jets with the slot for a flat head screwdriver is the hex main jets are keihin jets (keihin carb is in the YFZ450) and the stubby jets are probably dyno jets ( if so you will need the dyno adapter to make them the same length as the keihin jets).

You should ask for jets for the keihin carburetor.....
 

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Originally posted by 03'z400@Feb 2 2004, 05:12 AM
yea i'm having the same problem...choke half on when cold (40-) and fine when it warm (60+)...and it does pop when I let off ...so thats a lean condition? btw I have a 172 main and 45 pilot....also does anyone know what the difference between the long hex main jets (stock style) and the stubby jets with the slot for a flat head screwdriver? I went to the dealer and thats what they gave me...it worked but am wondering if there is a reason for the longer jets?
Alba I take it? They almost did that to me and i was like "No! wrong jets buddy"

Im running a 180 MJ, 45 pilot, 2.5 out on air screw, blue JD needle on 3rd clip and runs perfect! a TAD rich though. This is with my rossier pipe
 

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You are gonna run the long hex jets as they stick deeper into the float bowl.
 

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Originally posted by YFZCentral+Feb 1 2004, 11:12 PM--></span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (YFZCentral @ Feb 1 2004, 11:12 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin--03'z400@Feb 2 2004, 05:12 AM
yea i'm having the same problem...choke half on when cold (40-) and fine when it warm (60+)...and it does pop when I let off ...so thats a lean condition? btw I have a 172 main and 45 pilot....also does anyone know what the difference between the long hex main jets (stock style) and the stubby jets with the slot for a flat head screwdriver? I went to the dealer and thats what they gave me...it worked but am wondering if there is a reason for the longer jets?
Alba I take it? They almost did that to me and i was like "No! wrong jets buddy"

Im running a 180 MJ, 45 pilot, 2.5 out on air screw, blue JD needle on 3rd clip and runs perfect! a TAD rich though. This is with my rossier pipe [/b][/quote]
nah it was north county yamaha, they were the closest shop to my work. I had to pick up some jets and they were the only shop I could make it to before everyone was closed....I really don't like that shop but had no choice
 

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Why does everyone have to grind the end off the stock needle when raising it?

I have no problem fitting the neeld back in in any position all the way to #7 if need be. The top scews back in fine and everything. Just curious.

By the way I dont know what its like in The US but here in Canada, BLue is WWWWAAAAAYYYYYYY Faster!! :lol
 
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