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new2blue450

how much is normal?

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i just got a 04 yz450f last night!! its great a great bike in great condition, but i was wandering :applause: how much back firing is normal? does air temp or engine temp make a differance? thanks in advance for any feed back!!

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It could be leaner because of the temp outside. You could back your fuel screw out about a half a turn to see if it stops. It could also be an exhaust leak.

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thats what i figured, fuel screw.....this is my first bike, only ridden 4 wheelers and never had and popping or backfiring from them,thats why i ask. can i mess up my bike if i mess with the fuel screw??

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thats what i figured, fuel screw.....this is my first bike, only ridden 4 wheelers and never had and popping or backfiring from them,thats why i ask. can i mess up my bike if i mess with the fuel screw??

Just don't open it much. If it is open more than 2 1/2 turns then it's time to change your jetting, but I don't think it will be a problem. It is harmful to run it lean however.

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thats what i figured, fuel screw.....this is my first bike, only ridden 4 wheelers and never had and popping or backfiring from them,thats why i ask. can i mess up my bike if i mess with the fuel screw??

No man.

We'll help you out.

Try to buy the manual for that bike. It's like the Bible of knowledge.

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so screw it in all the way and then out 2-1/2 turns? is the zip-ty a good idea? and how often do you have to mess with the screw?

BTW thanks for putting up with me....lol

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so screw it in all the way and then out 2-1/2 turns? is the zip-ty a good idea? and how often do you have to mess with the screw?

BTW thanks for putting up with me....lol

All of us cool kids have the zip ty screw, its worth every penny.

Your adjustment is correct as you describe.

You use the screw to make it perfect so just about ever ride. It's really no big deal.

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perfect, and how much do the zip ty's run, can seem to find it on RM, and is there any other mods you would suggest? this bike is all stock, except for the precision concept suspention..

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perfect, and how much do the zip ty's run, can seem to find it on RM, and is there any other mods you would suggest? this bike is all stock, except for the precision concept suspention..

http://ziptyracing.com/display/eCommerce/Products.asp?CategoryID=110&order=

That's what it looks like. You can order from there or the TT store. I've ordered from both places and its very safe and secure.

http://shop.thumpertalk.com/default.asp

Do a search in this forum for your bike and you'll find a wealth of information. It's all here. Try that search thingy out, seriously. You'll be an expert on your bike in no time. Read every thread I've linked, I did your search for you. :applause:

http://www.thumpertalk.com/forum/search.php?searchid=937054

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so screw it in all the way and then out 2-1/2 turns? is the zip-ty a good idea? and how often do you have to mess with the screw?

BTW thanks for putting up with me....lol

YES and YES get the fuel screw! You will adjust often - I do.

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Just remember when you screw in the new Zip-Ty fuel screw......

Screw it in till it LIGHTLY makes contact, you don't want to really screw it in tight because you will crush the little tip at the end and render your adjustments moot. Just turn it in till it lightly seats, than count the number of turns out.

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I had a problem with backfiring after rolling off the throttle in fifth gear. I got used to it and I think you won't have any problem if left alone. The problem was finely solved when I de-carboned the head and valves after doing a top end on my 98 400. It sounds like you ride in the deserts east of San Diego if you have precision concepts suspension. I wouldn't push my bike out of the garage until they reworked my valving.

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