Got my first Yamaha. Are fuel screws different from Hondas?

I used to have a '05 CRF 250X. I had pulled the carburetor a couple of times so I was familiar with it. I knew where the fuel screw was and had replaced it. The stock fuel screw was also visible when just looking at the bike.

I just picked up a '07 YZ450F. I went to the track yesterday to start breaking it in. I had to make a very minor adjustment to the idle (I hadn't started riding at the track yet). While doing so I noticed the lack of a fuel screw. I could not see it. Is it supposed to be visible? I see the hole where it came out on my 250X.

Now what I'm wondering is are Yamaha's different? Both carburetors are Keinin so I imagine design is the same. Or did my fuel screw already fall out? I had never touched it and prior to arriving to the track I putted around for less than 1 mile. But what is weird is my bike ran fine yesterday so that's why I'm confused about it falling out.


You can not see the fuel screw if jou are just kneeling down looking at the side of the carb. You can see the hole where the fuel screw is but not the fuel screw Your best bet is to buy an aftermarket fuel screw. Just take the existing spring, brass washer and o-ring and put it on the after market fuel screw and screw it back in. If your bike is running good,screw the existing fuel screw all the way in and count how far it's out so when you put the new one in you know exactly how many turns it needs to be out. I bought my fuel screw at rockmountainatvmc and it was $20.00. You can also buy them here at the TT store

I think the fuel screws are the same. I have one from a Honda in my 06YZ450 right now.

Well I just meant in terms of visibility from looking on the side of the bike.

No you won't be able to see it, just the hole on the bottom of the carb in front.

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