Jet kit anyone?
#11
03-14-2008, 03:37 PM
#12
03-17-2008, 12:38 PM
Senior Member
Join Date: Jun 2006
Location:
Posts: 445
Likes: 0
Received 0 Likes
on
0 Posts
RE: Jet kit anyone?
ORIGINAL: Nauree
You tune the vacuum levels to make them even thoughout the carbs.
ORIGINAL: brveagle
Care to explain how the f4 carbs can be tuned? The jets are what control the amount of fuel the engine sees. The only thing you can "tune" on the carb is to adjust the idle mixture. Thats it
ORIGINAL: PlayfulGod
160 - 170 miles is bout normal for my F4. And mine has a full D&D exhaust and a K&N on it. I dont know if it has a jet kit or not, But I suspect a stage 1 has been installed. But carbs can be tuned, and not necessarily need rejetted.
ORIGINAL: jessej05
i bought my bike a month and a half ago now and the guy i bought it form said it was jetted. i have a k&n and a two bros slip on. now i have not torn it apart to make sure it was jetted. but i did have two stickers on the side(laughing out loud). ne ways i ran my tank one time just to see what i got and my trip meter said 163 and the light came on. this is with a lot of high rpms to cuz i was practicing wheelies and riding fast. i think thats normal right?
i bought my bike a month and a half ago now and the guy i bought it form said it was jetted. i have a k&n and a two bros slip on. now i have not torn it apart to make sure it was jetted. but i did have two stickers on the side(laughing out loud). ne ways i ran my tank one time just to see what i got and my trip meter said 163 and the light came on. this is with a lot of high rpms to cuz i was practicing wheelies and riding fast. i think thats normal right?
#13
03-28-2008, 04:47 AM
RE: Jet kit anyone?
Fun stuff.......heres what ive been told...yes you can run with a slip on and filter on stock jetting. Have also been told if you are running a high flow baffle slip on and aftermarket high flow filter that a stage 1 kit will help smooth out the powerband, and not necessarily give you more power. That being said I'm running a slip on and k&n with stock jetting and it runs ok, however, i do have a stage one kit i just got and have yet to install. As for "tuning" or "syncing", thats pretty much mandatory when you jet a bike anyway. And if you ask me...its not the jets that will kill your mileage, its the sprocket changes 
sure plays havoc on my mileage but its a fair trade.
sure plays havoc on my mileage but its a fair trade.
#14
03-28-2008, 06:39 PM
Senior Member
Join Date: Aug 2007
Location:
Posts: 100
Likes: 0
Received 0 Likes
on
0 Posts
RE: Jet kit anyone?
From what I've read, F4's run leanish in the middle rpm range for emmisions reasons, and for MPG reasons. They run a bit rich up top to help will cooling and to make sure that the bike can handle altitude changes. By adding a jet kit, your usually going to wind up putting more fuel into the carbs. If your bike is a bit weak in the middle and feels like its starving for fuel, the jetkit will help. Though the bikes had a small hole around 4-5k rpms even from the factory. When you put a full exhaust, or a slipon/k&n, you are increasing the amount of air that goes through the engine and this creates a leaner mixture all around. The bike will run better up top because of the leaner mixture compared to the factory slightly rich mixture. The bike MAY run a bit worse in the middle ranges because its making a lean mixture even more so. Not all bikes will need a jetkit, the best way is to just ride it and see if it feels like its strugling for fuel. I know two brothers recomends the stock jetting with the stock filter for the best overall power. I currently have a K&N on my bike, but I just ordered an OEM honda one to see if it makes my midrange better. By rejetting and putting a full exhaust on, your peak numbers might increase, but you will most likely loose some in the mid range. Sorry for the long post. Let me know if you have any questions.
#15
03-28-2008, 07:35 PM
RE: Jet kit anyone?
I put a yosh and K&N on my bike 3000 miles after i bought it. The bike had a very noticeablelack ofpower around the midrange 5-7k rpm. The yosh and k&n made a noticeable difference in that blank spot. I put on a stage 1 around 10k miles of having the k&n and yosh on. The powerband was noticeably smoother, and bythe seat of mypants it feels faster.
the jets decreased my mileage from 160 miles to the light, to 145 or so to the light now.
the jets decreased my mileage from 160 miles to the light, to 145 or so to the light now.
#16
03-31-2008, 08:23 AM
RE: Jet kit anyone?
ORIGINAL: DonEverett
From what I've read, F4's run leanish in the middle rpm range for emmisions reasons, and for MPG reasons. They run a bit rich up top to help will cooling and to make sure that the bike can handle altitude changes. By adding a jet kit, your usually going to wind up putting more fuel into the carbs. If your bike is a bit weak in the middle and feels like its starving for fuel, the jetkit will help. Though the bikes had a small hole around 4-5k rpms even from the factory. When you put a full exhaust, or a slipon/k&n, you are increasing the amount of air that goes through the engine and this creates a leaner mixture all around. The bike will run better up top because of the leaner mixture compared to the factory slightly rich mixture. The bike MAY run a bit worse in the middle ranges because its making a lean mixture even more so. Not all bikes will need a jetkit, the best way is to just ride it and see if it feels like its strugling for fuel. I know two brothers recomends the stock jetting with the stock filter for the best overall power. I currently have a K&N on my bike, but I just ordered an OEM honda one to see if it makes my midrange better. By rejetting and putting a full exhaust on, your peak numbers might increase, but you will most likely loose some in the mid range. Sorry for the long post. Let me know if you have any questions.
From what I've read, F4's run leanish in the middle rpm range for emmisions reasons, and for MPG reasons. They run a bit rich up top to help will cooling and to make sure that the bike can handle altitude changes. By adding a jet kit, your usually going to wind up putting more fuel into the carbs. If your bike is a bit weak in the middle and feels like its starving for fuel, the jetkit will help. Though the bikes had a small hole around 4-5k rpms even from the factory. When you put a full exhaust, or a slipon/k&n, you are increasing the amount of air that goes through the engine and this creates a leaner mixture all around. The bike will run better up top because of the leaner mixture compared to the factory slightly rich mixture. The bike MAY run a bit worse in the middle ranges because its making a lean mixture even more so. Not all bikes will need a jetkit, the best way is to just ride it and see if it feels like its strugling for fuel. I know two brothers recomends the stock jetting with the stock filter for the best overall power. I currently have a K&N on my bike, but I just ordered an OEM honda one to see if it makes my midrange better. By rejetting and putting a full exhaust on, your peak numbers might increase, but you will most likely loose some in the mid range. Sorry for the long post. Let me know if you have any questions.
#17
03-31-2008, 12:20 PM
RE: Jet kit anyone?
ok i really have no comparison accept racing. my bike has a two bros slip on and a k&n. i was told it was jetted but how would i know with out tearing it apart. but as far as the race i did a 2nd gear drop with my buddies 04 r6 (he has custom exhaust, airfilter, and 520 sprocket) we did it in 2nd at 50-65 mph and he pulled a lil at first but then when i shifted i started to pass, and continued to pull. its very peppy and seems to have just as much mid range as low and high. the guy i bought it from said it has a stage 1 dyno jet kit. i doubt this helps at all haha but o well.
#18
04-01-2008, 09:29 PM
Senior Member
Join Date: Aug 2007
Location:
Posts: 100
Likes: 0
Received 0 Likes
on
0 Posts
RE: Jet kit anyone?
I didn't know Two Brothers made a full kit for the F4's? Either way, if you notice a loss of power in the mid range you may want to jet it. Depending on which kit you go with, you won't be able to go back to stock if you would choose to do so, so be aware of that. I don't see any reasons why a jet kit would hurt, other then MPG's.
#19
04-02-2008, 11:05 AM
RE: Jet kit anyone?
ORIGINAL: DonEverett
I didn't know Two Brothers made a full kit for the F4's? Either way, if you notice a loss of power in the mid range you may want to jet it. Depending on which kit you go with, you won't be able to go back to stock if you would choose to do so, so be aware of that. I don't see any reasons why a jet kit would hurt, other then MPG's.
I didn't know Two Brothers made a full kit for the F4's? Either way, if you notice a loss of power in the mid range you may want to jet it. Depending on which kit you go with, you won't be able to go back to stock if you would choose to do so, so be aware of that. I don't see any reasons why a jet kit would hurt, other then MPG's.