CBR 600F4 1999 - 2000 Honda CBR 600F4 Forum

need help installing jet kit

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Old 05-18-2010, 10:45 PM
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Default need help installing jet kit

I got the factory pro jet kit, but 140 on the outside carbs and 142 on the inside carbs, put the new needles in on the 3rd clip from the top.

Started the bike, and it spits around 5-8.

the paper it came with says fuel screw 2 turns to start, I do not know where the fuel screw is, so this is more than likely my problem, anyone know where the fuel screw is, please don't say in the float bowls, I really am hoping to not take the carbs off again.

so I guess my main question is

Where is the fuel screw

This is with giannelli slip on and k&n filter

and are these normal jet selections, or should I have done 38 outside and 40 inside, and Is my clip setting ok?
 
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Old 05-19-2010, 04:16 AM
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ok I found the fuel screw, i set them to 2 turns out from seated, the instructions say 2 turns out, but they dont say if it is 2 turns from seated, or 2 turns from factory setting
 
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Old 05-19-2010, 10:45 AM
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Lightly seat them then back them out required turns. If it's sputtering from 5-8K rpm's, it isn't your fuel screws but your needles.
 
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Old 05-19-2010, 11:46 AM
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so should I move the clip up a notch or down?
 
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Old 05-19-2010, 09:27 PM
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Only way to tell for sure is to get bike to where it's sputtering and shut motor off, coast to a stop and pull a plug. Or if it's easier, just go one direction and note the change. Whichever way is easier for you.
 
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Old 05-20-2010, 01:28 AM
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ok now I have the needle set to clip #4 which cleared up the sputter, have the fuel screws dialed in, and the bike pulls like crazy up top now, and it runs good down low, but between 5-8 it has a dead spot where it seems to stop making power, but no longer spits and sputters.
I think I should try the last needle adjustment #5, what do you think?

bike runs awesome besides lacking power from 5-8

at 8 the power comes on way harder than ever before and stays on till redline

if the #5 clip setting does not work I will try smaller jets maybe 138 outer and 140 inner

please any thoughts from people with carb/jetting experience would be helpfull, I know jetting is pretty much trial, but experience is everything with this
 
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Old 05-20-2010, 07:42 PM
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If you went to clip pos. #4 you were fattening up the needle. Going to a smaller main would be defeating the purpose as it seem engine is wanting more fuel. Go back up on clip position and try next larger size main.
 
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Old 05-21-2010, 02:31 AM
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i moved the needle to #5, the bike is running good now, no bad spots

if I go one size bigger on the main now, do you think there is more power to gain up top? or would that mean I would have to start all over and find a good needle setting all over agian

as it is now, down low and mid have a really noticable increase in power, up top feels like it gained a little, but I think there is more power to be gained up top by using the bigger jets, the bike definatly is faster tho, really brought the slip on and k&n filter to life!
 
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Old 05-21-2010, 10:56 AM
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It certainly wouldn't hurt to try different sizes. Plug checks are your best friend. They tell you what's going on and they never lie.
 
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Old 05-21-2010, 03:53 PM
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Why did you purchase a jet kit for a slip on/filter?

I'm curious as to whether you actually are gaining any "power".

Remember, more fuel doesn't equal more power. In fact it's the opposite. Lean is mean.

I run stock jets on my f4 with a D&D pipe and k&n and have no issues what so ever.
 


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