Another CARB set up thread
11-01-2013, 07:11 AM
#31
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
Follow up:
Pulled one shim from the rear carb before a 3500 mile trip last month.
rideability remains excellent, fuel mileage increased some 20 miles per tank.
I'll get some dyno time here in the next few days if all goes as planned... will be interesting to see what the AF is
Pulled one shim from the rear carb before a 3500 mile trip last month.
rideability remains excellent, fuel mileage increased some 20 miles per tank.
I'll get some dyno time here in the next few days if all goes as planned... will be interesting to see what the AF is
11-01-2013, 08:31 AM
#32
Senior Member
Superstock
Join Date: Apr 2013
Location: Seattle
Posts: 250
You guys are killing me... y'all live too far away! I need a local expert that can be bought (or borrowed) with a six pack of beer!
I have my carbs in pieces, and I'm almost scared about putting them back together, and trying to get all those hoses right.
I took loads of pictures before and during disassembly, but I'm really wishing I had labeled and numbered each one. V engines always get me in trouble, I'm an inline four guy.
I have my carbs in pieces, and I'm almost scared about putting them back together, and trying to get all those hoses right.
I took loads of pictures before and during disassembly, but I'm really wishing I had labeled and numbered each one. V engines always get me in trouble, I'm an inline four guy.
02-12-2014, 09:32 PM
#34
Rex Kramer-Thrill Seeker
SuperBike
Join Date: Jan 2011
Location: Brookfield, WI
Posts: 2,312
E., have you messed with the carbs anymore or hit the dyno lately?
I'm getting as much information possible crammed into my grey matter before tackling my carb tuning with the F.I.L. (Filter In Lid) mod. I'm going to miss the 130-150 miles per tank!
I'm getting as much information possible crammed into my grey matter before tackling my carb tuning with the F.I.L. (Filter In Lid) mod. I'm going to miss the 130-150 miles per tank!
02-13-2014, 06:06 AM
#35
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
Feels about the same, need to get back on the dyno to confirm the AF.
My AF monitoring planes on a stand alone on board system got set aside as Im putting all funds and time toward a new venture.
Im teaching an MSF class at the shop on Friday... if weather is not bad I might get the bike down there for a quick pull.
08-30-2014, 03:39 PM
#37
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
Fat, fat, fat
The current setup 175/178, 48 pilots (Mikuni brand jets), Honda OEm needles all OEM shims plus 1 additional .030 shim per needle, OEM long slide springs, is waaaaay rich... pilot circuit, transition to and main jet
Like almost plug killing rich. ...idles at 11.4 drops to 10 and lower just off idle and stays at 11.1-12.3 all though the main circuit.
So back to 45 pilots and no extra shims under the stock needles with the current 175/178 mains and I'll run it again in the next few days.
Bottom line
At least on my bike the "magic carb set up" while not un rideable
It is slow to rev out . Stinky rich. And the AFR does not lie .... It's just Plain way rich
The current setup 175/178, 48 pilots (Mikuni brand jets), Honda OEm needles all OEM shims plus 1 additional .030 shim per needle, OEM long slide springs, is waaaaay rich... pilot circuit, transition to and main jet
Like almost plug killing rich. ...idles at 11.4 drops to 10 and lower just off idle and stays at 11.1-12.3 all though the main circuit.
So back to 45 pilots and no extra shims under the stock needles with the current 175/178 mains and I'll run it again in the next few days.
Bottom line
At least on my bike the "magic carb set up" while not un rideable
It is slow to rev out . Stinky rich. And the AFR does not lie .... It's just Plain way rich
Last edited by E.Marquez; 11-04-2018 at 12:48 PM.
08-30-2014, 06:11 PM
#38
Senior Member
SuperSport
Join Date: Apr 2013
Posts: 972
Fat, fat, fat
The current setup 175/128, 48 pilots (Mikuni brand jets), Honda OEm needles all OEM shims plus 1 additional .030 shim per needle, OEM long slide springs, is waaaaay rich... pilot circuit, transition to and main jet
Like almost plug killing rich. ...idles at 11.4 drops to 10 and lower just off idle and stays at 11.1-12.3 all though the main circuit.
So back to 45 pilots and no extra shims under the stock needles with the current 175/178 mains and I'll run it again in the next few days.
Bottom line
At least on my bike the "magic carb set up" while not in rideable
It is slow to rev out . Stinky rich. And the AFR does not lie .... It's just Plain way rich
The current setup 175/128, 48 pilots (Mikuni brand jets), Honda OEm needles all OEM shims plus 1 additional .030 shim per needle, OEM long slide springs, is waaaaay rich... pilot circuit, transition to and main jet
Like almost plug killing rich. ...idles at 11.4 drops to 10 and lower just off idle and stays at 11.1-12.3 all though the main circuit.
So back to 45 pilots and no extra shims under the stock needles with the current 175/178 mains and I'll run it again in the next few days.
Bottom line
At least on my bike the "magic carb set up" while not in rideable
It is slow to rev out . Stinky rich. And the AFR does not lie .... It's just Plain way rich
09-03-2014, 07:42 AM
#42
Well take off, eh.
SuperBike
Join Date: Jun 2012
Location: QC, Canada
Posts: 1,201
Good show Erik. 2 Questions: Are you running the stock stacks, or Dr. Honda's ? Also, have you ended up blocking a hole on the rear slide, or just the front ?
The stack question is the most important, since this affects airflow to the carbs alot in comparison to the stock.
The stack question is the most important, since this affects airflow to the carbs alot in comparison to the stock.
09-03-2014, 08:20 AM
#43
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
Good show Erik. 2 Questions: Are you running the stock stacks, or Dr. Honda's ? Also, have you ended up blocking a hole on the rear slide, or just the front ?
The stack question is the most important, since this affects airflow to the carbs alot in comparison to the stock.
The stack question is the most important, since this affects airflow to the carbs alot in comparison to the stock.
Currently
Plugged one factory slide hole and the one drilled for the DJ kit install in the front slide. On the rear slide, I plugged just the DJ kit drilled hole, leaving the OEM ones.
The tuner Im working with on the dyno has more than 30 years of experience, he is a former World Superbike racer, then mechanic, from back when carbs ruled the track.
So based on his advice and several hours of dyno time so far..we are going back to stock.
Not dissing the carb set up many have found to work... just that, it's not working on my bike,, and the AFR clearly proves that.
09-03-2014, 11:55 AM
#44
Senior Member
SuperSport
Join Date: Apr 2014
Location: Auckland, new Zealand
Posts: 932
OEM stacks
Currently
But when I install the 45 pilots I'll be drilling the factory hole again.
The tuner Im working with on the dyno has more than 30 years of experience, he is a former World Superbike racer, then mechanic, from back when carbs ruled the track.
So based on his advice and several hours of dyno time so far..we are going back to stock.
Not dissing the carb set up many have found to work... just that, it's not working on my bike,, and the AFR clearly proves that.
Currently
But when I install the 45 pilots I'll be drilling the factory hole again.
The tuner Im working with on the dyno has more than 30 years of experience, he is a former World Superbike racer, then mechanic, from back when carbs ruled the track.
So based on his advice and several hours of dyno time so far..we are going back to stock.
Not dissing the carb set up many have found to work... just that, it's not working on my bike,, and the AFR clearly proves that.
10-16-2014, 03:55 PM
#45
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
Round 3:
Carbs came out today, new slides (factory holes only) new jets (factory size and brand) new plugs, and air cleaner.
Going to base line the bike on the Dyno saturday... Lets see what this perceived seat of the pants issue is that so many have "cured" by adding enough fuel to feed a GT car at Le Mans.
Starting to wonder is the OEM jetting is nearly as bad as some have posted after using a SEAToPANTS dyno to decide shimming needles, bugger jets, blocking slide holes was the answer.
Carbs came out today, new slides (factory holes only) new jets (factory size and brand) new plugs, and air cleaner.
Going to base line the bike on the Dyno saturday... Lets see what this perceived seat of the pants issue is that so many have "cured" by adding enough fuel to feed a GT car at Le Mans.
Starting to wonder is the OEM jetting is nearly as bad as some have posted after using a SEAToPANTS dyno to decide shimming needles, bugger jets, blocking slide holes was the answer.
10-17-2014, 05:47 PM
#46
Senior Member
Superstock
Join Date: May 2012
Location: UK
Posts: 397
Interestingly after fitting stacks im leaning it off all over. Just dropped .5mm shims as blowing black smoke on the needles. Probably heading back to 45 idles to.
Erik I really appreciate what your doing here with all this testing and dyno's in-between. Thanks.
For the record I ran totally standard for a while apart from Micron non race cans (totally baffled street legal) when I first had the bike. IIRC I had some carb farts and stalling issues which I cured with the TPS, a tweak of the Mixture and obviously carb balancing. The bike ran beautifully, idled perfect and was smooth all the way through, fuel consumption wasn't too bad either, when taking it easy. But by the seat one thing always niggled me, it always felt a little flat. And then the tinkering began LOL
What AF's are you aiming for and where? Are you starting off on the lean side and then going a little richer towards the top? Which exhaust can do you think is best for taking a reading from or should both sides be probed and then let the dyno do the calculations? Sorry for all the questions but I would be interested in your opinion.
I was reading something interesting the other day that got me thinking.
The following is copied and pasted snippets (notes) I took while surfing the web. Sorry I couldn't say from where exactly or how reliable a source they are.
Note 1:
A fuel air ratio of 12.5 : 1 is good for maximum power, 17 : 1 is good for fuel economy and 14.7 : 1 is the ideal for complete burning and lowest emissions. Most people try for 14.7 since this is where the engine runs best and since too rich (12:5) wastes fuel, and too lean (17:1) makes an engine run hot. There are other things such as air temperature and barometric pressure which vary quite a bit so a carburetor is not set up for peak power (or maximum economy) unless you are prepared tweak it like racers do just before each race.
Note 2 (this I found particularly interesting):
neither cylinder is always leaner or richer. through the rpm and TP range, it can vary a bit. a dual cylinder tune is better than a single cylinder tune, and an experienced tuner can make a good dual cylinder map in just a few hours. but is it necessary? nope. a good single cylinder tune is good enough for most people. since it is tuned based on both cylinders, the average may be 13:1, but one cylinder might actually be 12:1 and the other 14:1. if the map is based solely on the cylinder that runs the leanest, it will be tuned for 13:1, while the other could be running at 11:1 on the other
(:-})
10-17-2014, 08:56 PM
#47
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
As for which pipe to draw samples from.... I've used both and not seen a huge difference . That is with OEM headers, to include the Y "restriction" and OEM cans that have been debaffled.
I have a set of headers at the coaters now that have O2 sensor bungs in them. The intent is to run a real time Af gauge set up at some point... but it could be used otherwise for the Dyno probe as well...
Last edited by E.Marquez; 10-17-2014 at 09:05 PM.
10-18-2014, 01:02 AM
#48
Senior Member
SuperBike
Join Date: Mar 2012
Location: New South Wales Australia
Posts: 1,544
Keep going mate.
This may just be the holy grail of carb set ups.
My bike is so finicky that by stopping an exhaust leak the carbs were out of sync.
I am running a DJ kit with no holes drilled, standard air filter, high comp J.E and a few other tweaks.
I love the power and torque but always feel there is more compared to my EFI bikes.
Watching this with interest.
Please keep us informed as to your progress as dyno time here in Oz I'd stupid $$$$ and I rely on my seat of the pants.
This may just be the holy grail of carb set ups.
My bike is so finicky that by stopping an exhaust leak the carbs were out of sync.
I am running a DJ kit with no holes drilled, standard air filter, high comp J.E and a few other tweaks.
I love the power and torque but always feel there is more compared to my EFI bikes.
Watching this with interest.
Please keep us informed as to your progress as dyno time here in Oz I'd stupid $$$$ and I rely on my seat of the pants.
10-18-2014, 03:41 AM
#49
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
One of my former Soldiers is a Tech now, rebuilds carbs for airplanes, he works in a shop that builds one brand and only a few dozen types of carbs.
Each carb is rebuilt where every passage, is redrilled to spec, every jet replaced THEN drilled to spec, every orifice redrilled.
Then each carb is run on a mammoth flow bench against a "Master" carb set of specs..
Fuel and air flow at many points and passages are checked.. anyone even slightly out of tolerance means the rebuild is rejected, and has to have adjustment.. another .0001 increase in a hole there, .001 reduced there.
Watching the process reminds me carbs are very imperfect..and the reason there is NO ONE perfect carb set up. Add to it the many other variables from a second carb bolted on via mechanical linkage, to engine and exhaust and it makes the myth of the common carb set up even more folly.
10-18-2014, 11:29 AM
#50
Banned
MotoGP
Join Date: Aug 2007
Location: Lake View Terrace, CA
Posts: 5,942
Yes there was a bit of road (or seat of the pants) testing thrown in to test real world ridablity.
So I do hope you get your stuff dialed in. All I can say is I have had good results with the set up I posted.
Like I have said many times, each bike is different and there is no "One" set up.
The only reason for this post is to clear up that Yes I did user a dyno to look at the fuel curves after each change I listed.... Shimmed needles, Larger pilots and the HRC blocked lift hole (just listing it that way as that is where the whole thing came from)
Carry on and good luck
10-18-2014, 11:55 AM
#51
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
Please post the Dyno results if you will.. I never saw them in your set up thread... The set up that worked on YOUR bike, failed to work on mine,, as we both could have guessed it would as, each bike, carb, are is different. .. Thats not a slam on you.. heck I liked your approach enough i copied it to see if it would work for me..It did not so Im on to a better approach
love to see your AF charts as you worked up your set up.
Thanks
Erik
10-18-2014, 02:28 PM
#52
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
Round three on the dyno
Butt dyno on the way to the shop says we are way off
No power, slow to rev
If I was missing a glove I'd look in the air box
Last edited by E.Marquez; 10-18-2014 at 04:47 PM.
10-18-2014, 03:07 PM
#53
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
And on to round 3.5
Something is amiss and it's not the set up.
One slide is not coming up.
The new used slides may be sticking in my carb body or there is a diaphragm issue.
So back apart it comes and we will see what we see.
Last edited by E.Marquez; 10-18-2014 at 04:48 PM.
10-18-2014, 04:09 PM
#54
Senior Member
SuperSport
Join Date: Apr 2014
Location: Auckland, new Zealand
Posts: 932
As this comment might be taken as an attack on the info I posted a while back all I will say is that when I did the set up work, it was all done on a dyno.
Yes there was a bit of road (or seat of the pants) testing thrown in to test real world ridablity.
So I do hope you get your stuff dialed in. All I can say is I have had good results with the set up I posted.
Like I have said many times, each bike is different and there is no "One" set up.
The only reason for this post is to clear up that Yes I did user a dyno to look at the fuel curves after each change I listed.... Shimmed needles, Larger pilots and the HRC blocked lift hole (just listing it that way as that is where the whole thing came from)
Carry on and good luck
Yes there was a bit of road (or seat of the pants) testing thrown in to test real world ridablity.
So I do hope you get your stuff dialed in. All I can say is I have had good results with the set up I posted.
Like I have said many times, each bike is different and there is no "One" set up.
The only reason for this post is to clear up that Yes I did user a dyno to look at the fuel curves after each change I listed.... Shimmed needles, Larger pilots and the HRC blocked lift hole (just listing it that way as that is where the whole thing came from)
Carry on and good luck
Thats off the table now with FIL. But the bike ran very well with it.
My set up Im currently reading the rear as to rich. Doing some plug reading. But am looking for a dual O2 gauge setup.
10-18-2014, 04:54 PM
#55
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
I have a very early 1st year VTR1000F... perhaps it has different carbs, head, valves, or just a combination of tolerances and worn parts ect that causes the "Hawk Set Up" to not work well on my bike. Thats not a knock on anyone else, just what I have to work with.
I look forward to reading the Dyno graphs and AF charts from Hawks many Dyno runs. It would greatly assist in displaying the changes he made and the effects it had.
Last edited by E.Marquez; 10-18-2014 at 04:57 PM.
10-20-2014, 04:15 AM
#56
Administrator
MotoGP
Thread Starter
Join Date: Apr 2006
Location: Kempner, TX
Posts: 4,402
Found a tear in the front carb slide diaphragm. Was large enough to cause the slide to lift slowly or not at all. Was not there on install, such is the way with install old used parts.
Ordered some new carb slides from Honda, stock order goes in this morning at work so I should have them mid week.
Ordered some new carb slides from Honda, stock order goes in this morning at work so I should have them mid week.
10-20-2014, 03:01 PM
#57
Senior Member
Back Marker
Join Date: Jul 2012
Location: Melbourne, Australia
Posts: 144
Found a tear in the front carb slide diaphragm. Was large enough to cause the slide to lift slowly or not at all. Was not there on install, such is the way with install old used parts.
Ordered some new carb slides from Honda, stock order goes in this morning at work so I should have them mid week.
Ordered some new carb slides from Honda, stock order goes in this morning at work so I should have them mid week.
Great work mate there is always a cause when things suddenly go wrong the bitch is finding it
10-22-2014, 01:53 AM
#58
Senior Member
SuperBike
Join Date: Mar 2012
Location: New South Wales Australia
Posts: 1,544
Keep going Erik!
I am happy with my set up but Dyno time is so expensive here that I can't really tell if all is well with my set up.
I rang a Dyno shop the other day and when I told the guy what I had he lost interest very quickly.
Words to the effect of too much drama for me are still ringing in my ears.
I am envious of you and look forward to your post with the new diaphragm when you get back on the dyno.
I am happy with my set up but Dyno time is so expensive here that I can't really tell if all is well with my set up.
I rang a Dyno shop the other day and when I told the guy what I had he lost interest very quickly.
Words to the effect of too much drama for me are still ringing in my ears.
I am envious of you and look forward to your post with the new diaphragm when you get back on the dyno.
07-04-2017, 09:00 AM
#60
Senior Member
Superstock
Join Date: Jul 2007
Location: CA, South of Heaven
Posts: 342
I don't mean to hijack this thread, but lots of carbs experience here, so rather than start a new one I just would like to post my DJ run. I got a bitchin lean spot at 3.5k. I can't see anymore the runs the OP posted to compare. Unfortunately the pics expired. But, at least for my bike, it's always been there, even when I dynoed it years ago. Oddly now it's causing misfires every time I cruise at that regime (1/8-1/4 throttle). Not sure if it's on the front or the rear since I didn't have separate AF probes during the runs. Other than that, the engine runs solid all the way to redline. What do you guys think could be the culprit? I'm using a pilot jet #45. Change it or maybe try first to raise the needles a notch? I'll appreciate any advices that may save me from going more insane than the last time I worked on the carbs. Thanks!
