Carb tuning...Low end (full throttle / 2k-3k)

1437 Views 7 Replies 3 Participants Last post by Y2KR1, Jul 21, 2002

Y2KR1

Discussion Starter · Jul 20, 2002

From Factory Pro:

If the engine has a "wet" rhythmic, soggy area at full throttle / 3k-4k rpm, that gets worse as the engine heats up, lower the fuel level by resetting the float height 1mm greater (if the original was 13mm - go to 14mm). This will lower the fuel level, making full throttle / 2k-3k rpm leaner.
If the engine is "dry" and flat between 2k to 3k rpm, raise the fuel level.

"wet" rhythmic, soggy area at full throttle / 3k-4k rpm"

How would you best describe this? Almost seems like a small studder, or slight shaking/hesitation in thie area.....

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dano5150

· #2 · Jul 21, 2002

Ok you're sure that it get worse as it gets warmer?? Now are you sure that you have a rich condition? I know kinda dumb questions but...
It's really hard to help w/ problems like this w/ out seeing the machine.
First, put you float level back to spec!! I don't know if you have a jet kit or not.
The low rpm isn't your float level.
Help me out here, what's done to you bike?
Sounds like you have a rich condition only cuz you said it get worse as you machine warms up. Usually machines are lean right at the spot! Did you drill your fuel screw caps yet? Well if it's for sure rich. you need to either turn in your fuel screws a quarter to a half turn. Or you may have to lower your needle (move the clip up). Just a hint, only do one thing at a time. If you don't you'll have no idea what what did.
Hope this helps. If you can fill me in on some more info I may be able to better help you! Good luck!

Ok man, I just read your whole question...lol hell I don't know how to describe that....uhhhh it runs like shit down low under full throttle. Anywhoo I don't know if this helps or not but just my 2cents

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Y2KR1

Discussion Starter · #3 · Jul 21, 2002

Thanks for the reply....it's a config 10 jet kit from factory pro, set to their initial starting suggestions (just re-did it on Friday) with a full micron pipe

My 900RR seems so much smoother from 1200-2500RPM, the R1 seems to have a slight stutter in the same range....I'll have Ken or someone take it out, and get their opinion

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ricerocket

· #4 · Jul 21, 2002

You'd probably be better off to just add 132.5 mains and turn the air/fuel mixture screws (under the brass plugs) out about 3.5 to 4 turns from lightly seated. Leave the pilots and the floats alone.

Most of the guys on our R1 board run Akrapovic exhausts which use a 4-1 header design rather than the 4-2-1 design, but the carb settings have worked pretty well all around. The 4-1 gives a better low end with the 4-2-1 typically sacrificing that area for a bit more top end power.

A full system "dip" between 3-4,000 rpm is almost impossible to work out on the pre '02 R1's with a full system.

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Y2KR1

Discussion Starter · #5 · Jul 21, 2002

ricerocket said:
You'd probably be better off to just add 132.5 mains and turn the air/fuel mixture screws (under the brass plugs) out about 3.5 to 4 turns from lightly seated. Leave the pilots and the floats alone.

Most of the guys on our R1 board run Akrapovic exhausts which use a 4-1 header design rather than the 4-2-1 design, but the carb settings have worked pretty well all around. The 4-1 gives a better low end with the 4-2-1 typically sacrificing that area for a bit more top end power.

A full system "dip" between 3-4,000 rpm is almost impossible to work out on the pre '02 R1's with a full system.

Rght now, I got the 135 Mains, #20Pilot's, 3x out on A/F screws, and 9.5MM on float level, as stated starting point from Factory Pro....

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ricerocket

· #6 · Jul 21, 2002

Y2KR1 said:
Rght now, I got the 135 Mains, #20Pilot's, 3x out on A/F screws, and 9.5MM on float level, as stated starting point from Factory Pro....

I just tore out a factory kit for another guy who was having low end problems. I've been into r1's since I bought mine in 98, and honestly haven't heard any good things about Factory or Dynojet kits for the r1. The hot setup would be a set of Ivan's needles and 132.5 mains with a 4-1 exhaust, but with the 4-2-1 your best results will be with 132.5 mains and around 3.5 turns out. I know it sounds too simple, but it is simple. R1's don't need jetting with slip-ons, and they really don't run half bad with no jetting and a full system.

I don't want to bash your jet kit, I just don't have any other simpler answers to give you other than what I've suggested.

If you have any other r1 specific questions or need more help, try asking on http://www.yzf-r1forum.com . We've got over 1000 R1 guys on there from all over the world and they can address just about any r1 problem you've got.

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ricerocket

· #7 · Jul 21, 2002

Another thought, did you syncronize your carbs after you instaled the kit? Carbs are pretty sensitive to the adjustments you made and a sync after you're done is almost necessary to get a smooth idle and just off idle transition.

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Y2KR1

Discussion Starter · #8 · Jul 21, 2002

ricerocket said:
I just tore out a factory kit for another guy who was having low end problems. I've been into r1's since I bought mine in 98, and honestly haven't heard any good things about Factory or Dynojet kits for the r1. The hot setup would be a set of Ivan's needles and 132.5 mains with a 4-1 exhaust, but with the 4-2-1 your best results will be with 132.5 mains and around 3.5 turns out. I know it sounds too simple, but it is simple. R1's don't need jetting with slip-ons, and they really don't run half bad with no jetting and a full system.

I don't want to bash your jet kit, I just don't have any other simpler answers to give you other than what I've suggested.

If you have any other r1 specific questions or need more help, try asking on http://www.yzf-r1forum.com . We've got over 1000 R1 guys on there from all over the world and they can address just about any r1 problem you've got.

I used the factory jet kit, becouse it came with my Micron full exhaust, which was a deal from somewhere

brand new, so I was not going to complain....

I was going to go with Ivan's needles and Akrapovic origionally....

I'll try swapping in the 132.5's, and go another 1/2 turn out...need to get better at working on the carbs w/o pulling them off....

Thanks ricerocket,

(I'm a member over at yzf-r1forum.com, just don't post over there much...)

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