Carb set up
07-01-2011, 09:51 PM
#121
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Location: Lake View Terrace, CA
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07-01-2011, 09:56 PM
#122
Senior Member
SuperBike
Join Date: Mar 2007
Location: Belgium, WI
Posts: 1,611
Now, I dont have a stock exhaust, but I am on the stock filter (finally, ran it tonight) and it is not happy with the lack (read, NOT ENOUGH) fuel that 50 slows at 2 turns were providing. I went to 3.5 turns and will be testing tomorrow. I also may need to shim needles differently from each other (as they are FPro and at the 2nd clip position from the top). I will see what it is like tomorrow, and go from there. My main goal here is to get it back in the upper 40's for FE.
Mains: 188, 185
Mains: 188, 185
07-03-2011, 02:13 PM
#123
Senior Member
SuperBike
Join Date: Mar 2007
Location: Belgium, WI
Posts: 1,611
First ride verdict:
If you haven't ditched your dynojet/factory pro needles for the stock ones, glued your front slide hole (1 of 2)...You are missing something nearly perfect. I just went from 185/188 mains and 50 pilots with a k&n to 175/178 and 45 pilots at 3.5 turns and it is nearly on. I would say, for my bike, 178/181 might be dead on. I imagine the FE is going to be great, and so many little quirks are fixed. Now, to change my signature...
If you haven't ditched your dynojet/factory pro needles for the stock ones, glued your front slide hole (1 of 2)...You are missing something nearly perfect. I just went from 185/188 mains and 50 pilots with a k&n to 175/178 and 45 pilots at 3.5 turns and it is nearly on. I would say, for my bike, 178/181 might be dead on. I imagine the FE is going to be great, and so many little quirks are fixed. Now, to change my signature...
07-06-2011, 05:24 AM
#128
ride it out
SuperSport
Join Date: Feb 2009
Location: NH
Posts: 745
The other day I replaced my slow jets with 48s
needles I lifted a bit
2.5 and 2.75 turns out f/r
my carb still spits every so often, am I still lean?
it really only happens on throttle transistions, like closed to open.
needles I lifted a bit
2.5 and 2.75 turns out f/r
my carb still spits every so often, am I still lean?
it really only happens on throttle transistions, like closed to open.
07-19-2011, 06:23 PM
#130
Junior Member
Squid
Join Date: Apr 2011
Location: Pinckney, Mi
Posts: 8
Had a misfire between 2 and 3k rpm with the dj set up, didnt matter whether I ran the stock or aftermarket cans. Finally found a set of unmolested carbs and put in the 48 pilot shimmed the front .036 and the rear .046 and installed the extra long velocity stack on the front cyl. Vast improvement, very smooth, feels like more low end torque although the topend might be a little less power, still too close to call. No more misfire, smooth as silk. Good set up!
07-19-2011, 07:07 PM
#131
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Location: Lake View Terrace, CA
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Had a misfire between 2 and 3k rpm with the dj set up, didnt matter whether I ran the stock or aftermarket cans. Finally found a set of unmolested carbs and put in the 48 pilot shimmed the front .036 and the rear .046 and installed the extra long velocity stack on the front cyl. Vast improvement, very smooth, feels like more low end torque although the topend might be a little less power, still too close to call. No more misfire, smooth as silk. Good set up!
Everything is a trade off, the trick is finding a balance that works for your application\riding style.
09-03-2011, 10:58 AM
#132
Junior Member
Squid
Join Date: Sep 2011
Posts: 10
I did this mod on a 2002 w/900 miles on the clock, bone stock with slipons only. All PAIR, airbox, air filter, PVC, everything is in place and working.
The bike had a bad surge, hunting at idle before I began the work. Had to idle at 1600 or it would stall. Carbs were out of sync bad, fixed.
After setting up the carbs as per the article, it was way too fat (rich). I only shimmed the needles 30 thou. So I put everything except the #48 back to stock, idle screws 2.5 & 2.75 turns out. Now the bike runs great and I have one small problem left that's kicking my ****. lol
It's doing this exactly VTR1000f Superhawk idle problem - YouTube
Now I see this complaint is all over the internet, but there seems to be no definitive solution. I've been tuning bikes for over 30 years, and never has been one that I couldn't straighten out. Till now. I've been all over with the mixture screws to no avail. Hey, got really good a pulling the carbs!
So, I'll take any suggestion at this point.
Thanks.
The bike had a bad surge, hunting at idle before I began the work. Had to idle at 1600 or it would stall. Carbs were out of sync bad, fixed.
After setting up the carbs as per the article, it was way too fat (rich). I only shimmed the needles 30 thou. So I put everything except the #48 back to stock, idle screws 2.5 & 2.75 turns out. Now the bike runs great and I have one small problem left that's kicking my ****. lol
It's doing this exactly VTR1000f Superhawk idle problem - YouTube
Now I see this complaint is all over the internet, but there seems to be no definitive solution. I've been tuning bikes for over 30 years, and never has been one that I couldn't straighten out. Till now. I've been all over with the mixture screws to no avail. Hey, got really good a pulling the carbs!
So, I'll take any suggestion at this point.
Thanks.
09-06-2011, 09:11 AM
#133
Senior Member
Back Marker
Join Date: May 2011
Location: Farnorcal
Posts: 160
Well its been a month or so since doing the changes. Even though its running way better than before. I think there is room for improvement. I pulled my plugs to see how they were looking after about 2k miles and both are looking rich.... with the rear plug looking more sooty. Both had little dots on the insulator though.Correct me if im wrong but doesnt that indicate a lean condition? Not sure whats going on there?
I do get some slight popping on decel. Nothing too bad. Gas mileage is around 100 until light comes on.
Ive tried running different octanes just for the heck of it and nothing seems to change other than my last tank of 91 seemed to run worse maybe. It has been very hot here as of late too.
My elevation is around 500ft.
Just to note Im running.... 48 jets...and I believe 178/180 with 2 turns out on mixture. .040 shimmed.
Pair removed. ca smog removed. Jardine exhaust. stock filter. tps 500ohms.
Last question.... turning the mixture screw out does what...lean it more?
Cant remember and the manual doesnt say. Thanks.
I do get some slight popping on decel. Nothing too bad. Gas mileage is around 100 until light comes on.
Ive tried running different octanes just for the heck of it and nothing seems to change other than my last tank of 91 seemed to run worse maybe. It has been very hot here as of late too.
My elevation is around 500ft.
Just to note Im running.... 48 jets...and I believe 178/180 with 2 turns out on mixture. .040 shimmed.
Pair removed. ca smog removed. Jardine exhaust. stock filter. tps 500ohms.
Last question.... turning the mixture screw out does what...lean it more?
Cant remember and the manual doesnt say. Thanks.
09-06-2011, 12:46 PM
#134
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Location: Lake View Terrace, CA
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The pilot screws control fuel flow on this model carb. So turning the screws out richens the mixture.
Last edited by 8541Hawk; 09-06-2011 at 12:51 PM.
09-06-2011, 12:50 PM
#135
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Location: Lake View Terrace, CA
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I did this mod on a 2002 w/900 miles on the clock, bone stock with slipons only. All PAIR, airbox, air filter, PVC, everything is in place and working.
The bike had a bad surge, hunting at idle before I began the work. Had to idle at 1600 or it would stall. Carbs were out of sync bad, fixed.
After setting up the carbs as per the article, it was way too fat (rich). I only shimmed the needles 30 thou. So I put everything except the #48 back to stock, idle screws 2.5 & 2.75 turns out. Now the bike runs great and I have one small problem left that's kicking my ****. lol
It's doing this exactly VTR1000f Superhawk idle problem - YouTube
Now I see this complaint is all over the internet, but there seems to be no definitive solution. I've been tuning bikes for over 30 years, and never has been one that I couldn't straighten out. Till now. I've been all over with the mixture screws to no avail. Hey, got really good a pulling the carbs!
So, I'll take any suggestion at this point.
Thanks.
The bike had a bad surge, hunting at idle before I began the work. Had to idle at 1600 or it would stall. Carbs were out of sync bad, fixed.
After setting up the carbs as per the article, it was way too fat (rich). I only shimmed the needles 30 thou. So I put everything except the #48 back to stock, idle screws 2.5 & 2.75 turns out. Now the bike runs great and I have one small problem left that's kicking my ****. lol
It's doing this exactly VTR1000f Superhawk idle problem - YouTube
Now I see this complaint is all over the internet, but there seems to be no definitive solution. I've been tuning bikes for over 30 years, and never has been one that I couldn't straighten out. Till now. I've been all over with the mixture screws to no avail. Hey, got really good a pulling the carbs!
So, I'll take any suggestion at this point.
Thanks.
As for you idle issue, what do you have the TPS set to?
09-06-2011, 01:33 PM
#136
Senior Member
Superstock
Join Date: Jul 2007
Location: Los Angeles & Winston Salem
Posts: 433
Juice.
As 8541hawk says. Setting the TPS and balancing the carbs allowed my bike to idle at 1100rpm with no carbs farts or cluck and die issues, and yea we all get real good at pulling carbs on this bike huh? My bike all stock with stock cans is currently running all stock jet sizes, One shim under each needle and 2 1/4 turns on the mixture screws. Runs perfect, needs very little choke on start up which leads me to think it could still do with less on the mixture screws? I junked all the pair and epa crap, but I don't think this makes any difference to how the bike runs.
Looking at your video, seems your bike still has to idle a little high, Also only 900 miles on a 2002 got to have been some gummed up carbs there for sure huh? maybe gummed up fuel filter? I'm sure there could also been some blockage somewhere else in the carbs? I would try setting the TPS and re-balance the carbs after you make any changes or pull the carbs. Good luck?
As 8541hawk says. Setting the TPS and balancing the carbs allowed my bike to idle at 1100rpm with no carbs farts or cluck and die issues, and yea we all get real good at pulling carbs on this bike huh? My bike all stock with stock cans is currently running all stock jet sizes, One shim under each needle and 2 1/4 turns on the mixture screws. Runs perfect, needs very little choke on start up which leads me to think it could still do with less on the mixture screws? I junked all the pair and epa crap, but I don't think this makes any difference to how the bike runs.
Looking at your video, seems your bike still has to idle a little high, Also only 900 miles on a 2002 got to have been some gummed up carbs there for sure huh? maybe gummed up fuel filter? I'm sure there could also been some blockage somewhere else in the carbs? I would try setting the TPS and re-balance the carbs after you make any changes or pull the carbs. Good luck?
09-06-2011, 03:31 PM
#137
Junior Member
Squid
Join Date: Sep 2011
Posts: 10
Thanks for the responses, I'm going to check the TPS setting as I belive the idle issue is not carb related. (not my bike in the vid, but the same exact issue) As for the 900 miles, the bike sat in the crate at the dealer for several years before it was put in service. I comletely disassembled and cleaned the carbs, sync'd em. I don't think it's anything gummed up related, it runs really strong without any hesitation or anything. Just that idle clunk/ping is the only issue that remains. It sounds like an engine ping anyway, thinking too much timing might be the casue. I may even put a new set of plugs in, but those looked fine when I pulled them to check the gap.
If the TPS is in spec or adjusting it won't fix the issue, I'm going to put the #45 pilots back in so it's 100% stock except for the slipons.
Ps: Friend of mine had the issue on his SH too btw, but sold the bike.
If the TPS is in spec or adjusting it won't fix the issue, I'm going to put the #45 pilots back in so it's 100% stock except for the slipons.
Ps: Friend of mine had the issue on his SH too btw, but sold the bike.
Last edited by Juice; 09-06-2011 at 03:35 PM.
09-06-2011, 03:55 PM
#138
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Location: Lake View Terrace, CA
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Couple of things..... first didn't realize it only had 900 miles on it.
So first, that is actually kind of normal until the engine is actually broken in. Get everything set right and give the bike around 5K miles to loosen up a little bit and it should go away....
The only other thing is did you only disassemble one carb at a time or did you take them both apart?
Just asking because besides the staggered jetting, the emulsion tubes are different from front to rear, so just something to check if you happened to mix the parts up.
So first, that is actually kind of normal until the engine is actually broken in. Get everything set right and give the bike around 5K miles to loosen up a little bit and it should go away....
The only other thing is did you only disassemble one carb at a time or did you take them both apart?
Just asking because besides the staggered jetting, the emulsion tubes are different from front to rear, so just something to check if you happened to mix the parts up.
09-07-2011, 12:04 AM
#140
Hi i am new in this forum, just got my VTR 2 weeks ago 
The bike has carbon exhausts and BMC filter, as from the previous owner said it had nothong done to the carbs just a bigger fuel pump(do know know how this will help to a carb bike). As a new bike i can`t say if its running right ot not, but its a speed train for me.
I previously had Suzuki GSX750f Katana, and did play will the carbs a lot. What surprised me when reading this thread is the pluging hole thing.
I had a DJ kit on my Katana and it had plugs to plug 1 or 2 holes on the slide(depending on what stage you want to go), and in the katana forum all members cursed this pluging as a bed thing, on the KTM forum they drilled even bigger holes to help better throttle responce, nad now i read here that DJ does the oposite thing for the VTRs and you still have to dissagree with them and plug the hole.
Just seemed pretty weird to me, and wanted to share.
SO.......just to show off a bit...here it is my little precious
The bike has carbon exhausts and BMC filter, as from the previous owner said it had nothong done to the carbs just a bigger fuel pump(do know know how this will help to a carb bike). As a new bike i can`t say if its running right ot not, but its a speed train for me.
I previously had Suzuki GSX750f Katana, and did play will the carbs a lot. What surprised me when reading this thread is the pluging hole thing.
I had a DJ kit on my Katana and it had plugs to plug 1 or 2 holes on the slide(depending on what stage you want to go), and in the katana forum all members cursed this pluging as a bed thing, on the KTM forum they drilled even bigger holes to help better throttle responce, nad now i read here that DJ does the oposite thing for the VTRs and you still have to dissagree with them and plug the hole.
Just seemed pretty weird to me, and wanted to share.
SO.......just to show off a bit...here it is my little precious
09-12-2011, 06:45 AM
#144
Junior Member
Squid
Join Date: Sep 2011
Posts: 10
Update: I went back to stock #45 and fine tuned the idle screws and re-synced the carbs. Set idle slightly higher than spec for the next few thousand miles.
IMO, this setup is too rich for a stock airbox setup even with aftermarket cans. I pulled the #48s as I was less than one turn on the mixture screws and it was still too rich at idle.
I'll give away a little tuning trick to get mixture at idle correct without a tailpipe sniffer. With the engine fully warmed up and aircleaner out and carb intakes accessible, spray a very tiny amount of Birkible 2+2 carb cleaner (a few drops only) into one carb at a time. If your idle goes up, you are too lean. If it kills the engine, it's too rich. When the idle drops by a 100 rpm or so and recovers, it's perfect!
Happy riding!
IMO, this setup is too rich for a stock airbox setup even with aftermarket cans. I pulled the #48s as I was less than one turn on the mixture screws and it was still too rich at idle.
I'll give away a little tuning trick to get mixture at idle correct without a tailpipe sniffer. With the engine fully warmed up and aircleaner out and carb intakes accessible, spray a very tiny amount of Birkible 2+2 carb cleaner (a few drops only) into one carb at a time. If your idle goes up, you are too lean. If it kills the engine, it's too rich. When the idle drops by a 100 rpm or so and recovers, it's perfect!
Happy riding!
09-26-2011, 01:41 PM
#146
Good Root
Squid
Squid
Join Date: Jul 2009
Location: Shoebox
Posts: 87
My mechanic is dead set against the use of non stock jets in the VTR and is of the opinion that damage is caused to the carb in doing so.
I had the opportunity to get hold of a stock untouched set of carbs and once I had the chance to pull the old set apart I found it interesting as to what had been done by the previous owner.
Mine was already thirsty but it would quickly degrade into a real guzzler after a couple of months. Turns out that it had #180 and #182 mains and #50 slow! This with the K&N needle jet was never going to be thrifty.
Then I pulled the jets out of the untouched carbs and it turned out to have #172 and #174 with a pair of #48S for the pilot! Score!
Now to get a stock air cleaner and carefully go through your setup and we'll see how we go, here's hoping...
I had the opportunity to get hold of a stock untouched set of carbs and once I had the chance to pull the old set apart I found it interesting as to what had been done by the previous owner.
Mine was already thirsty but it would quickly degrade into a real guzzler after a couple of months. Turns out that it had #180 and #182 mains and #50 slow! This with the K&N needle jet was never going to be thrifty.
Then I pulled the jets out of the untouched carbs and it turned out to have #172 and #174 with a pair of #48S for the pilot! Score!
Now to get a stock air cleaner and carefully go through your setup and we'll see how we go, here's hoping...
09-26-2011, 01:56 PM
#147
Senior Member
MotoGP
Join Date: Mar 2007
Location: Phoenix, AZ
Posts: 3,132
Update: I went back to stock #45 and fine tuned the idle screws and re-synced the carbs. Set idle slightly higher than spec for the next few thousand miles.
IMO, this setup is too rich for a stock airbox setup even with aftermarket cans. I pulled the #48s as I was less than one turn on the mixture screws and it was still too rich at idle.
IMO, this setup is too rich for a stock airbox setup even with aftermarket cans. I pulled the #48s as I was less than one turn on the mixture screws and it was still too rich at idle.
09-30-2011, 04:16 PM
#149
Good Root
Squid
Squid
Join Date: Jul 2009
Location: Shoebox
Posts: 87
My mechanic is dead set against the use of non stock jets in the VTR and is of the opinion that damage is caused to the carb in doing so.
I had the opportunity to get hold of a stock untouched set of carbs and once I had the chance to pull the old set apart I found it interesting as to what had been done by the previous owner.
Mine was already thirsty but it would quickly degrade into a real guzzler after a couple of months. Turns out that it had #180 and #182 mains and #50 slow! This with the K&N needle jet was never going to be thrifty.
Then I pulled the jets out of the untouched carbs and it turned out to have #172 and #174 with a pair of #48S for the pilot! Score!
Now to get a stock air cleaner and carefully go through your setup and we'll see how we go, here's hoping...
I had the opportunity to get hold of a stock untouched set of carbs and once I had the chance to pull the old set apart I found it interesting as to what had been done by the previous owner.
Mine was already thirsty but it would quickly degrade into a real guzzler after a couple of months. Turns out that it had #180 and #182 mains and #50 slow! This with the K&N needle jet was never going to be thrifty.
Then I pulled the jets out of the untouched carbs and it turned out to have #172 and #174 with a pair of #48S for the pilot! Score!
Now to get a stock air cleaner and carefully go through your setup and we'll see how we go, here's hoping...
Runs well, rides so much better. Now needs sync and final mix setup and jobs done. TPS was way out, > 900 ohm, and had to work hard to get exactly 490
Its sooo smooth from nothing, no hint of carb backfire which nearly always happened from cold. No exhaust backfire either on deceleration.
Now tempted to dyno it to get it spot on.
10-05-2011, 09:02 PM
#150
Member
Squid
Join Date: Sep 2011
Posts: 48
8541hawk, thanks for this info but I have a question about the shims:
" So what I do when setting up a set of carbs is remove the stock thin washer that is under the front needle and leave it in place on the rear. With this method you actually end up with the front needle approx. .030" higher than stock and the rear .040" higher than stock which seems to work well."
The 'thin' factory installed washers are .020" thick. How are you getting a .010" differential by leaving out the stock .020" shim from the front?
Am I interpreting the total shim stack correctly based on your statement above since both needles come stock with a .020" shim?:
Front:.050"
Rear:.060"
TIA for clarifying, maybe I'm just dense or something.
" So what I do when setting up a set of carbs is remove the stock thin washer that is under the front needle and leave it in place on the rear. With this method you actually end up with the front needle approx. .030" higher than stock and the rear .040" higher than stock which seems to work well."
The 'thin' factory installed washers are .020" thick. How are you getting a .010" differential by leaving out the stock .020" shim from the front?
Am I interpreting the total shim stack correctly based on your statement above since both needles come stock with a .020" shim?:
Front:.050"
Rear:.060"
TIA for clarifying, maybe I'm just dense or something.
