i have the carb farts
10-20-2011 | 06:05 AM
#31
Out of my mind, back in 5
MotoGP
Joined: Nov 2006
Posts: 6,109
From: Skurup, Sweden
My bike does occasionally have the odd carb fart, usually if I go off throttle to abrubtly... But not often enough that I can relate to what others here talk about...
If a bike behaves like this, it's setup the wrong way, as simple as that... And 9 times out of 10, the VTR's i have come across is set too rich... Syncronisation or lack there of does make the bike act up a lot, so I'd start there... And BTW, the spec that the manual states as "OK", is where i start when mine are out of sync... You can get the difference down to nearly zero without too much effort, and it's well worth it...
10-20-2011 | 12:14 PM
#32
Senior Member
Superstock
Joined: Jan 2011
Posts: 258
From: Santa Clara, CA
I've been rebuilding carbs (and tuning them) for years and the superhawk that I own and work on almost daily still has some issues in the carbs. It takes a little bit of time and some work to get them to where as they're perfect, like everything else.
With the variety of mods done to these bikes, there's no cut and paste solution to every carb, only general help tips and places to look to see how to solve your particular problem.
01-27-2012 | 04:39 PM
#37
Senior Member
Superstock
Joined: Jul 2007
Posts: 433
From: Los Angeles & Winston Salem
Ok, Does anyone here actually have a Superhawk that does not FART once in awhile? I've owned three and they all seem to do it to. You can tune them to run really smooth, but your still going to get a hicup or fart every now and then.
01-27-2012 | 05:34 PM
#40
Banned
MotoGP
Joined: Aug 2007
Posts: 5,942
From: Lake View Terrace, CA
01-27-2012 | 05:35 PM
#41
Banned
MotoGP
Joined: Aug 2007
Posts: 5,942
From: Lake View Terrace, CA
When it's common, then there is a problem
01-27-2012 | 05:36 PM
#42
Connie Demico does toad?
Superstock
Joined: Oct 2011
Posts: 383
From: Lakeway
I have none of these issues on a 39k mile used bike. I have not checked the synch but it is on the short list. The bike has hiccuped slightly a couple of times at idle over the last few thousand miles, but nothing I would complain about unless it did get chronic.
01-27-2012 | 05:37 PM
#43
Banned
MotoGP
Joined: Aug 2007
Posts: 5,942
From: Lake View Terrace, CA
01-27-2012 | 07:46 PM
#45
Senior Member
SuperSport
Joined: Aug 2009
Posts: 684
From: Richmond, VA
01-28-2012 | 12:17 AM
#46
Senior Member
MotoGP
Joined: Sep 2006
Posts: 4,138
From: Austin, Tx
I had the same performance issue in the 2-3k rpm range because this is the range where the pilot (meaning first) jets hand off to the mains. If the mains don't come on strong enough at that handoff the engine starts to run out of fuel and it clatters. I ride my Superhawk primarily around town so I use that 2-3k rpm band alot.
After just a few short rides, I took it back to my tech. He rode it up the parking lot and back down. Put it in the shop. "I'll call ya when it's ready."
I get back to the office, check in w/everybody and barely get my *** in the chair, Tim is on the phone. "It's ready." I go up to the shop and he says go ride so I get out on the service road, roll it on, good through first, smooth into second, on ramp to the freeway coming up and I think - why not? The roll on from 45mph in third to 110 was just like sitting on a rocket. Full on. I get back and find out he used the 45's and went to the 48's - IIRC. Huge difference in performance - no more dead spot.
At that moment I understood the tuning dynamic of the Superhawk. It runs and breathes like a tractor. The more you unleash it the more fuel and air it needs. And yes, I think my current build would rev until it blew. I don't think this monster runs out of torque until that very moment.
This is worth getting right.
Lots of things make a Superhawk, cough, puke up through the carbs or clack. The carbs have to be synced everytime you take them off. Don't use premium grade fuels. They hate being cold and the more they're hopped up the worse it is. They don't like being overly hot either. The heat causes them to run lean at idle.
If you're new to the Superhawk these noises are a reason for concern to you. As you get more time on the bike it's no big. Little wrist action to clear the carbs and pissoff the bitches on their phones - you're good to go.
After just a few short rides, I took it back to my tech. He rode it up the parking lot and back down. Put it in the shop. "I'll call ya when it's ready."
I get back to the office, check in w/everybody and barely get my *** in the chair, Tim is on the phone. "It's ready." I go up to the shop and he says go ride so I get out on the service road, roll it on, good through first, smooth into second, on ramp to the freeway coming up and I think - why not? The roll on from 45mph in third to 110 was just like sitting on a rocket. Full on. I get back and find out he used the 45's and went to the 48's - IIRC. Huge difference in performance - no more dead spot.
At that moment I understood the tuning dynamic of the Superhawk. It runs and breathes like a tractor. The more you unleash it the more fuel and air it needs. And yes, I think my current build would rev until it blew. I don't think this monster runs out of torque until that very moment.
This is worth getting right.
Lots of things make a Superhawk, cough, puke up through the carbs or clack. The carbs have to be synced everytime you take them off. Don't use premium grade fuels. They hate being cold and the more they're hopped up the worse it is. They don't like being overly hot either. The heat causes them to run lean at idle.
If you're new to the Superhawk these noises are a reason for concern to you. As you get more time on the bike it's no big. Little wrist action to clear the carbs and pissoff the bitches on their phones - you're good to go.
Last edited by nuhawk; 01-28-2012 at 12:32 AM.
01-28-2012 | 04:10 AM
#47
Senior Member
Superstock
Joined: Oct 2011
Posts: 344
why not?
my bike runs great in this range, doesn't feel like its lugging, and I usually shift between 3k and 3500 if I'm just putting around on the street...I'll rev a bit higher if I'm riding 2 up so the engine doesn't have to work hard at lower rpm.
my bike runs great in this range, doesn't feel like its lugging, and I usually shift between 3k and 3500 if I'm just putting around on the street...I'll rev a bit higher if I'm riding 2 up so the engine doesn't have to work hard at lower rpm.
10-03-2018 | 09:55 PM
#48
Junior Member
Squid
Joined: Jan 2014
Posts: 13
From: Columbia, SC
Ok, I know this is an really old thread but I just got my bike run again after not running for a year. Carbs were beyond gunked up. I bought a can of Berryman's stripped them down to nothing (done this several times), replace the pet **** cover assembly (made a huge difference) and not my bike is carb farting until it warms ups. I have NEVER turned the air/fuel mixture screws (they are still at factory settings) and I am using factory jets. I synced the carbs with a vacuum gauge albeit, I am not sure if that was the best method. Has anyone synced carbs with a single vacuum gauge? Also, how did you adjust the sync screw with the airbox still on? I shut the bike down, used a small wrench and turned the screw, then started it back up and checked vacuum on each port until I got close to the same vacuum while holding idle at 3k.
10-04-2018 | 07:14 AM
#49
Administrator
MotoGP
Joined: Apr 2006
Posts: 4,402
From: Kempner, TX
Im hoping you mean adjusted, not that you tried to clean the carbs with the mixture screws in place.
Did you strip the carbs down completely? Or dunk them together?
There is an access hole in the plastic deflector on the right side that you can reach the sync screw. I use a 1/4" drive driver handle an extension and a flex joint socket.
Doing it once with the tank off so you can better see what your doing will make it easier to figure out the needed tools from what you have or need and the technique.
I cant imagine getting a correct Carb Sync the way you described doing it.....It really needs to be running and the Sync done with your choice of dual gauges. There are Home made Manometers all the way to electronic digital stuff. I am using these right now https://www.carbtune.com
Did you strip the carbs down completely? Or dunk them together?
There is an access hole in the plastic deflector on the right side that you can reach the sync screw. I use a 1/4" drive driver handle an extension and a flex joint socket.
Doing it once with the tank off so you can better see what your doing will make it easier to figure out the needed tools from what you have or need and the technique.
I cant imagine getting a correct Carb Sync the way you described doing it.....It really needs to be running and the Sync done with your choice of dual gauges. There are Home made Manometers all the way to electronic digital stuff. I am using these right now https://www.carbtune.com
10-04-2018 | 07:05 PM
#50
Junior Member
Squid
Joined: Jan 2014
Posts: 13
From: Columbia, SC
Yes, I have never removed the idle/air screws. I have always been told not to. I will try to fabricate a sync tool. I really do not want to buy anything for this bike as I am selling it. I have owned if for 15 years, it has never been wrecked or dropped, or raced (with the seldom gentle wheelie), and as of lately I have dumped more money into than I care to think about.
it does backfire on cold starts for some reason. Could this be related to carb sync?
it does backfire on cold starts for some reason. Could this be related to carb sync?
10-04-2018 | 09:59 PM
#52
Senior Member
MotoGP
Joined: Jul 2007
Posts: 5,053
From: NYC
It sounds very lean to me. Did you try running it with the choke slightly pulled to see if it improves?
I had a terrible issue recently and used the jack flash thumb screws to richen the mixture and it now runs like new.
For what they cost its worth it. Otherwise you are removing the carbs every adjustment. A week of that and you may be in good shape but I am not that patient. Plus I need to ride the bike daily.
I had a terrible issue recently and used the jack flash thumb screws to richen the mixture and it now runs like new.
For what they cost its worth it. Otherwise you are removing the carbs every adjustment. A week of that and you may be in good shape but I am not that patient. Plus I need to ride the bike daily.
10-06-2018 | 09:20 AM
#53
Junior Member
Squid
Joined: Jan 2014
Posts: 13
From: Columbia, SC
Ok, I think I found the problem. I have an intake leak. I replaced the carb boots this last time around. I sprayed carb cleaner around the boots. it revved up, then died. I had a feeling they were not set when I installed them. could this be the culprit? Anyone had this problem before?
10-06-2018 | 10:35 AM
#54
Senior Member
SuperBike
Joined: Sep 2008
Posts: 1,707
From: Essex, UK
Ok, I think I found the problem. I have an intake leak. I replaced the carb boots this last time around. I sprayed carb cleaner around the boots. it revved up, then died. I had a feeling they were not set when I installed them. could this be the culprit? Anyone had this problem before?
10-07-2018 | 07:18 AM
#56
Administrator
MotoGP
Joined: Apr 2006
Posts: 4,402
From: Kempner, TX
Only when they get Old and hard...normally two things that do not go together,. but are common on motorcycle rubber intake manifolds. Replace them once and awhile with new ones, and the need to tighten the band clamp to within an inch of its limitations goes away.
10-07-2018 | 09:47 AM
#58
Junior Member
Squid
Joined: Jan 2014
Posts: 13
From: Columbia, SC
Ok, I am struggling here. I THOUGHT I had the front boot tighted down pretty good. I check back this more, and the damn thing has come unseated. Now and I have a really high idle (major intake leak). I used a little bit of motor oil on the rubber to make it easier to seat otherwise, its so tight it wont go on. Any idea to fix this? I am just before junking this bike that I have spent 1000 dollars on in the past year and have not put one mile on it.
10-07-2018 | 10:07 AM
#59
Junior Member
Squid
Joined: Jan 2014
Posts: 13
From: Columbia, SC
Ok, I pulled the carbs BACK off for the 7 time. took carb cleaner to the METAL and cleaned the engine and carb body. Washed the carb boot in dish detergent and water. Will put back together. Just for future reference, do NOT use motor oil on the carb boots. its cause you not to be able to get tight and the essentially slip off the engine.
