Oh, and it started doing this once I put the ivans needles and stock jets in to fix a previous problem- engine would not accelerate past 9K rpm. That is fixed now, but this new problem appeared.

 

why did you only install Ivan's needles and not the whole kit?
everybody swears by Ivan's crap, put in the whole kit & if it still has a problem call Ivan.

 

ivans kit is just needles.. it uses stock mains.. if i remember correctly.. tho it may come with one size up for pipe and filter.. been long time since i put mine in.. if its top end problem.. thats main jets. or fuel delivery problem.. maybe kinked hose??? change plugs??

 

didn't know he doesn't provide main jets with the R1 kit.
I remember the FZ1 kit has smaller main jets than stock so I assumed something similar for the R1.

 

i remember on mine.. with slip on it retained stock jet size.. but i think it came with one size larger and one smaller... but damn.. that was like 7 years ago... glad i have pc and wide band.. no more taking carbs off cept when working on other peoples bikes

 

From what I understand, main jet size that I have (130) is perfect for my setup since it pulls hard all the way to redline. I'm thinking maybe some sort of float problem, but I'm trying to find out if anyone has ever seen this. I called Ivan already, and he told me to check a bunch of things- float level, vacuum diaphragms, etc. All is fine, and the plugs are brand new NGKs, also.

Do the pilot or air jets play any role under these conditions?

Thanks for the replies.

 

I thought Ivans kit is for exup headers. Try change the clip on the needle m8.
Allow a bit more fuel to run.

Regards,

 

only a/f figure will tell you whether the bike at said speed/rpm is rich or lean with 130's. try 132.5s and set the floats to std if they are not and report back.

 

Ivan's kit comes with 132.5 mains, for use with a full system using the stock air box and stock filter.

with only a slip-on the stock 130 mains are retained.

If you mod the air box as Ivan has shown and use an aftermarket filter in conjunction with a full system then you use the stock 130 mains. Still has that same top end power, but will now accelerate from low rpm without the stumbling.

 

he basically has a full system (no exup) and motor mods.... so maybe it is lean? anyway going up one jet size wont hurt anything anyway. or maybe lift the needle 1 notch.

 

I already tried going up (rich) one notch on the needles, and it wouldn't accelerate cleanly in midrange, like it was loading up. If I gave it full throttle, it would bog. I had an Innovate Motorsports wideband on it, and it was running 12.5-13.0 afr at wide open at higher speeds. When I let off throttle, it would jump to 20-25:1 afr. Everyone I've asked says this should be normal due to the throttle plates suddendly closing and incomplete combustion happening.

What circuit exactly has the most effect on high rpm close/open throttle? There is no accelerator pump like there is on cars. Maybe my slides need to be drilled so they open quicker?

I'm almost at the point of buying another set of carbs from ebay, put ivans needles in them, and just saying hell with it.

 

needles and main jet are the circuits used. maybe your exhaust is a limiting factor?:dunnoand why not just try the 132.5s? they are in ivans kit anyway.... sometimes especially with carbs it is trial and error. as you have so many variables.....eg: pilot jet.main airjet, main fuel jet, needle taper and positions, float levels, a'f screw turns, etc.
here have a read.http://www.factorypro.com/tech/carbtun.html
http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

 

I put 132.5's in, checked float height again (was ok), turned mixture screws out to 4 turns, and cut 2 loops from the slide springs (to weaken them). The stumble/hesitation is now completely gone. However, it falls on its face at WOT around 9k rpm (too rich?). If I back of the throttle, it keeps accelerating. Also, midrange power seems down a little and exhaust note is noticeably deeper. It does idle much, much better. How could 132.5 mains be too rich for my setup? Even on a stock bike, they shouln't be too rich, should they?

 

no they shouldn't, but unfortunately you changed 3 things at the same time so go back to 130s and dont change anything else and see what happens? unfortunately with carbs it's a slow process of elimination without a a/f data logging capability like i have with a wideband commander.

 

Also, am I safe to assume that all of my other jets are stock, since they have no numbers/markings on them?

 

it sounds too rich. follow blur1's advice & only change 1 thing at a time.
also be careful cutting the springs 'cause if you cut too much you can get flutter & if the springs are too weak you could get the stumble you're talking about at 9 grand.
you say it falls flat at wot at 9 grand, is that at wot & when it gets to 9 or if you are at 9 & then go wfo?

 

It pulls clean from ~4k to about 9k holding wot, any gear. once it hits around 9k, it starts breaking up and surging/not accelerating. Midrange power is also down quite a bit. I rode it again tonight, and couldn't pull it up, even in 1st. 130's are going back in, and I'll have to check it again......

 

It pulls clean from ~4k to about 9k holding wot, any gear. once it hits around 9k, it starts breaking up and surging/not accelerating.

if it's surging that's lean.
had you already clipped the springs before ?

I know it sounds stupid but maybe you need to start from the beginning.
with carb tuning you start at the top & work down.

1) select the main jet that produces the highest top speed.
2) select the needle position that allows clean acceleration.

I know it's a pita but there are so many variables with carbs that it's easy to get confused/overlook something.

 

What you have described is a condition where the throttle shuts complete and no A/F mixure gets past the butter flies. Belive it or not but the eng requires some air fuel mixtuer and idle speed upon fast chopping of the trottle to alow for a faster transiton to off throttle to back on.

What happens is, when the Air/Fuel is shut off completly now, there is only air between the trottle blades and the intake. This comes into play when you want to get back on the gas fast, the dead air pocket with no fuel to mix with the air and burn has to go thru the ingine first, and thus creating a dead spot or lag as you try to accelerate. May sound like you just ran out of gas, or backfiring, or just a bog. Also it is more aparent at high eng speeds and high throttle opening position, and high gear.

To cure this take the carbs completely apart clean it blow out all of the circuits, with a can of carb cleaner. Next pull out the piolit jet, air jet , and emulsifyer if it has one. check all holes and pssages ensure they are not pluged or damamaged. Next pull out the starter choke valve insure plungers, o rings , spring are all in good shape



As you are blowing out all the curciuts make sure you see the carb cleaner coming out of different port and they all act the same.


Don't set your float levels to low you could be starving for fuel on deccel also. set them about 8 mm with a float gauge if you have one, I eyeball the proper float level, and I have been around longenough it works for me.

Next sync and balance, go thru the procedure at least 3 time and blip the trottle a few time in between. final setting of your pilot adusting screw should be between 1 and 3 1/2 turns out, if less then one go to a smaller pilot jet, over 3 1/2 turn larger pilot jet is needed.. This is assming you have all ready selected the main jet and the neddle position. I may take you 20 times going iinto the carbs to get the A/F mixure right.

All of this should get rid of the decell lag. Every eingines need some kind of close throttle enricher to kill the lag. I knot sure how these carb do it, I think the pilot air jet and the pilot jet , or maybe the choke plunger does it.

Maybe some one will chim in and agree or disaree. I am allways ready to learn.

 

If your pilot jet is stock (15) go up to a 17.5. try an ivans or factory pro neddle , you should check the main for proper size first, your setup indicates to me the 130 main will be ok. Do a carefull tune on the syncing and the fuel screw, run thru it at least 3 time, and each time recalibrate the carb sticks. Also each time adjust the fuel screws. Be very detailed when you do this and make sure your readings are repeatable. When tuning the idle mixture use a tach and your ears to get it just right . 1/4 turn wrong can make a big diffrerenc.

Let us know how it goes

 

If your pilot jet is stock (15) go up to a 17.5. TRY AN IVANS OR FACTORY PRO NEEDLE , you should check the main for proper size first, your setup indicates to me the 130 main will be ok. Do a carefull tune on the syncing and the fuel screw, run thru it at least 3 time, and each time recalibrate the carb sticks. Also each time adjust the fuel screws. Be very detailed when you do this and make sure your readings are repeatable. When tuning the idle mixture use a tach and your ears to get it just right . 1/4 turn wrong can make a big diffrerenc.

Let us know how it goes

a couple of points:

1) He already has Ivan's needles.
2) The idle mixture is not going to have a noticeable affect on high speed on/off throttle.
3) Maybe I'm wrong but I don't think his carbs have blades.

maybe someone can correct me if I'm wrong.

 

fixed!!!

Ok, so it's finally figured out. I had a couple of idle mixture screws broken. The end(needle) of them were broken off and blocking the passage into the throttle body. This was probably causing too lean of a mixture when throttle was closed, which explains the hesitation, as it was probably killing those 2 cylinders momentarily. It runs a lot better now. Just have to throw a wideband on again for peace of mind. Thanks a bunch for the help!

 

thanks for the update.