Finicky carb tuning
07-07-2005, 01:14 AM
#1
Guest
Posts: n/a
Finicky carb tuning
is there anyone who has had great success with jetting their carbs? I'm looking around and everyone says its a pain in the ***. (well that's the nature of carbs i know 
) I was seriously considering jetting carbs and degreeing the cams, but there are a lot of posts about people saying that it never ran that great anymore and yielded a measely <10hp. I like the bike, its comforterable, but I hate being just on-par with some 600cc 4 bangers
01 Black VTR
RS3 slipon Yoshi's, stock carbs, stock box
) I was seriously considering jetting carbs and degreeing the cams, but there are a lot of posts about people saying that it never ran that great anymore and yielded a measely <10hp. I like the bike, its comforterable, but I hate being just on-par with some 600cc 4 bangers01 Black VTR
RS3 slipon Yoshi's, stock carbs, stock box
07-07-2005, 09:40 AM
#2
Member
Squid
Join Date: May 2005
Location: Nashville, TN
Posts: 84
If you consider it logically, by modifying anything on your bike, you're essentially saying you think you are smarter than Honda's engineers. I have a PhD, and I don't think I'm smarter than those good folks in Japan. I've made mods, and usually there's bad that comes with the good. It's always a compromise. My carbs are jetted and seriously tweaked, and my bike runs great...but my fuel mileage sucks. Ask the folks who've tried the TPS mod about how much smarter they are than the Honda engineers. 8)
If it ain't broke, don't fix it. Jet kits are usually not a big deal for experienced tuners, but if your bike is running well now, and the spark plugs read right, leave it alone. If "keeping up with the Joneses" is a priority to you, your best bet is to take the money you'd spend modifying your VTR, and spend it on a bike that is faster from the factory.
...but I never follow my own advice. 8)
If it ain't broke, don't fix it. Jet kits are usually not a big deal for experienced tuners, but if your bike is running well now, and the spark plugs read right, leave it alone. If "keeping up with the Joneses" is a priority to you, your best bet is to take the money you'd spend modifying your VTR, and spend it on a bike that is faster from the factory.
...but I never follow my own advice. 8)
07-07-2005, 10:28 AM
#5
Senior Member
SuperBike
Join Date: Jul 2004
Posts: 1,015
Re: Finicky carb tuning
Oh well i guess another Nashvillian can chime in too. I sorta of agree with SuperChicken, but i am a tinkerer and enjoy working on my ride as much as i enjoy riding her.
Yes the TPS mod is noticable
Yes the K&N filter is noticable
Yes the Jet kit (tuned right) is noticable
All that being said if you don't plan on a Dyno run with Fuel/Air mixture info before and after the mods then you will never know.
I added all the above including the Factory Pro ignition Advancer and my ride Air/fuel mixture is spot on from the bottom to the top, not to rich, not too lean right in the sweat spot.
I went with the Factory Pro TI kit, used their needles and mains, bought Honda 48 pilots when i determined the 50 pilot that come in the kit are too big and cause the bike to surge. I also added the front emulson tube to the rear carb ( or was that vice versa would have to check my notes) as reccommended by Factory pro.
It's all up to you and how mechanically inclined you are and how patient you are.
Most all that complain about Jet Kits, pipes, K&N filters and so on either didn't have the patience to fine tune the carbs (multiple Tank removals) or didn't have the correct tools or mecanical skill set to be doing it in the first place. Finally some go to a dealer for this work, what a money suck that is, chances of them geting the right jetting the first time is very slim and do you think they are going to fine tune the carbs a second or third time for free, well NO.
Yes the TPS mod is noticable
Yes the K&N filter is noticable
Yes the Jet kit (tuned right) is noticable
All that being said if you don't plan on a Dyno run with Fuel/Air mixture info before and after the mods then you will never know.
I added all the above including the Factory Pro ignition Advancer and my ride Air/fuel mixture is spot on from the bottom to the top, not to rich, not too lean right in the sweat spot.
I went with the Factory Pro TI kit, used their needles and mains, bought Honda 48 pilots when i determined the 50 pilot that come in the kit are too big and cause the bike to surge. I also added the front emulson tube to the rear carb ( or was that vice versa would have to check my notes) as reccommended by Factory pro.
It's all up to you and how mechanically inclined you are and how patient you are.
Most all that complain about Jet Kits, pipes, K&N filters and so on either didn't have the patience to fine tune the carbs (multiple Tank removals) or didn't have the correct tools or mecanical skill set to be doing it in the first place. Finally some go to a dealer for this work, what a money suck that is, chances of them geting the right jetting the first time is very slim and do you think they are going to fine tune the carbs a second or third time for free, well NO.
07-07-2005, 10:29 AM
#6
Senior Member
SuperSport
Join Date: Mar 2005
Location: Laurel, MD
Posts: 758
Yep. I've succesfully tuned a Factory kit. There is a slight richness between 34-3600 rpm that causes a burble on steady state throttle, but otherwise everything is fine.
Frankly, carb jetting is not for the novice or impatient person. But its a valid mod for more power. It also requires some individual initiative. Each engine is a little different.
The biggest mistake most novices make is to just pop in the biggest jets. The second mistake is an unwillingness to R&R the carbs enough times to get it right.
Frankly, carb jetting is not for the novice or impatient person. But its a valid mod for more power. It also requires some individual initiative. Each engine is a little different.
The biggest mistake most novices make is to just pop in the biggest jets. The second mistake is an unwillingness to R&R the carbs enough times to get it right.
07-07-2005, 10:41 AM
#7
Senior Member
SuperBike
Join Date: Jul 2004
Posts: 1,015
Re: Finicky carb tuning
07-07-2005, 11:05 AM
#8
Senior Member
MotoGP
Join Date: Jan 2005
Location: Gainesville FLA.
Posts: 3,844
Re: Finicky carb tuning
Amazinglly, from what everyone else has posted, I put the Factory jet kit in mine with no problems. Set it like the instructions and beside very little adjusting and I mean very little it ran like a top from day one.
No blurbs, burps, crackles, snorts, flat spots etc. Guess I'm too good or more likely just damn lucky! :P
No blurbs, burps, crackles, snorts, flat spots etc. Guess I'm too good or more likely just damn lucky! :P
07-07-2005, 11:50 AM
#9
Senior Member
SuperSport
Join Date: Mar 2005
Location: Laurel, MD
Posts: 758
Re: Finicky carb tuning
07-07-2005, 02:26 PM
#10
Remember stock is BAD!
SuperSport
SuperSport
Join Date: Jun 2004
Location: Jacksonville FL
Posts: 760
Re: Finicky carb tuning
No problem tuning in my carbs. I did have to remove the tank a total of 2 times though.
The jet kit fixes the flat spot up top and gives better (stronger) throttle response down low.
The jet kit fixes the flat spot up top and gives better (stronger) throttle response down low.
07-07-2005, 03:29 PM
#11
Senior Member
SuperSport
Join Date: Dec 2004
Location: Nananimo, B.C.
Posts: 764
Re: Finicky carb tuning
Jacking this thread a bit here but...I'm thinking my bike might be running lean but instructions I've read say that in order to set your main jets, I need to see which jet pulls a higher top speed.
Holy crap?! I've hit 260km/h before and frankly, it was kinda nerve wracking. I don't relish seeing if 195 mains will pull 264km/h. Is there another way w/o a dyno??
Holy crap?! I've hit 260km/h before and frankly, it was kinda nerve wracking. I don't relish seeing if 195 mains will pull 264km/h. Is there another way w/o a dyno??
07-07-2005, 06:29 PM
#13
Senior Member
SuperSport
Join Date: Dec 2004
Location: Nananimo, B.C.
Posts: 764
Re: Finicky carb tuning
"To get the best, most even top end power (full throttle/after 5000 rpm), select the main jet that produces the highest top speed / pulls hardest at high rpm."
Finding the highest top speed isn't as subjective as "pulls hardest at high rpm".
I have a place where I can do it in relative saftey and I use the word "relative" loosely. I just get the creeps going that speed at high rpm with all the noise that something's going to blow, ya know?
Finding the highest top speed isn't as subjective as "pulls hardest at high rpm".
I have a place where I can do it in relative saftey and I use the word "relative" loosely. I just get the creeps going that speed at high rpm with all the noise that something's going to blow, ya know?
07-07-2005, 06:39 PM
#14
Guest
Posts: n/a
If you consider it logically, by modifying anything on your bike, you're essentially saying you think you are smarter than Honda's engineers. I have a PhD, and I don't think I'm smarter than those good folks in Japan. I've made mods, and usually there's bad that comes with the good. It's always a compromise. My carbs are jetted and seriously tweaked, and my bike runs great...but my fuel mileage sucks. Ask the folks who've tried the TPS mod about how much smarter they are than the Honda engineers. 8)
If it ain't broke, don't fix it. Jet kits are usually not a big deal for experienced tuners, but if your bike is running well now, and the spark plugs read right, leave it alone. If "keeping up with the Joneses" is a priority to you, your best bet is to take the money you'd spend modifying your VTR, and spend it on a bike that is faster from the factory.
...but I never follow my own advice. 8)
If it ain't broke, don't fix it. Jet kits are usually not a big deal for experienced tuners, but if your bike is running well now, and the spark plugs read right, leave it alone. If "keeping up with the Joneses" is a priority to you, your best bet is to take the money you'd spend modifying your VTR, and spend it on a bike that is faster from the factory.
...but I never follow my own advice. 8)
Never owned a carburated vehicle in my life, only fuel injected Mitsubishi's 6g72 turbo and 4g64 stroker turbo to be exact. Frankly, I ******* hate these medival pieces of ****, excuse my french. I'd love to tear into the bike, but I'm not very patient, and the carbs are a mess to remove (done once before due to a low speed jet clog)Just wonder how much power can you pull out of this engine with the basic mods and jetting? Of course, I wouldnt think of fine tuning carbs without a dynometer and that itself is $$.
Thanks
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