carb setup.
06-29-2012 | 09:35 AM
#1
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SuperSport
Joined: Aug 2010
Posts: 506
From: Toronto, Ontario, Canada
carb setup.
I've got a dynojet kit installed by the PO. I have read through the carb setup threads in the knowledge base.
I was thinking of changing the mains back to the stock keihin jets, running the dynojet needles, filling the extra slide holes, and keeping the Dynojet needles.
I'd rather not mix and match parts, but if I can't source the stock bits, I may have little choice (at least for the time being...)
Anyone have any experience in doing this?
The stock needles may be pretty decent, but can I just adjust the clips to the stock needle height and use the needles I have?
I was checking out the conversion chart for keihin to DJ jets... Seems with a 185f and 190r DJ needle, I'm at the equivalent of a keihin 208f & 215r... Unreal.
If I baby it with this setup, I still get over 100 miles to the tank, mostly highway running, constant 70-80mph.
I was thinking of changing the mains back to the stock keihin jets, running the dynojet needles, filling the extra slide holes, and keeping the Dynojet needles.
I'd rather not mix and match parts, but if I can't source the stock bits, I may have little choice (at least for the time being...)
Anyone have any experience in doing this?
The stock needles may be pretty decent, but can I just adjust the clips to the stock needle height and use the needles I have?
I was checking out the conversion chart for keihin to DJ jets... Seems with a 185f and 190r DJ needle, I'm at the equivalent of a keihin 208f & 215r... Unreal.
If I baby it with this setup, I still get over 100 miles to the tank, mostly highway running, constant 70-80mph.
07-03-2012 | 04:44 PM
#3
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SuperSport
Joined: Aug 2010
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From: Toronto, Ontario, Canada
I haven't checked up on this thread in a coupe days.
I'll be putting a new stock filter in it.
I'm going to be putting the jetting back to stock, and running the dynojet needles and springs. My plan is to fill one lift hole in the front slide (the one dynojet has us drill...)
I need to figure out what the clip height on the aftermarket needles is comparable to the stock needle height.
If anyones got a measurement on the stock needles that'd help. (betting the top position is the same as stock, but I'm not quite sure...)
I'll be putting a new stock filter in it.
I'm going to be putting the jetting back to stock, and running the dynojet needles and springs. My plan is to fill one lift hole in the front slide (the one dynojet has us drill...)
I need to figure out what the clip height on the aftermarket needles is comparable to the stock needle height.
If anyones got a measurement on the stock needles that'd help. (betting the top position is the same as stock, but I'm not quite sure...)
07-03-2012 | 05:06 PM
#4
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MotoGP
Joined: Aug 2007
Posts: 5,942
From: Lake View Terrace, CA
I haven't checked up on this thread in a coupe days.
I'll be putting a new stock filter in it.
I'm going to be putting the jetting back to stock, and running the dynojet needles and springs. My plan is to fill one lift hole in the front slide (the one dynojet has us drill...)
I need to figure out what the clip height on the aftermarket needles is comparable to the stock needle height.
If anyones got a measurement on the stock needles that'd help. (betting the top position is the same as stock, but I'm not quite sure...)
I'll be putting a new stock filter in it.
I'm going to be putting the jetting back to stock, and running the dynojet needles and springs. My plan is to fill one lift hole in the front slide (the one dynojet has us drill...)
I need to figure out what the clip height on the aftermarket needles is comparable to the stock needle height.
If anyones got a measurement on the stock needles that'd help. (betting the top position is the same as stock, but I'm not quite sure...)
So if you are going to start mixing and matching parts you will be pretty much on your own to figure out how to get it all to work, IMHO.
07-03-2012 | 05:41 PM
#5
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Superstock
Joined: Jun 2005
Posts: 489
From: San Antonio, TX
If you have been running a stock air filter with those 185/190 mains, your mid-range has been extremely rich and will partially account for the low fuel mileage.
I have more testing to do, but so far the results have been excellent using Keihin mains and DJ needles and springs along with a BMC street air filter. I would also like to plug the front slide lift hole and see how she runs, and then possibly stagger the needle height.
As for the chart you referenced, I have absolutely no confidence in it's accuracy.
As best I can recall, the stock needle height corresponds to the #4 groove on the DJ needles. I will double check that when I have time.
I have more testing to do, but so far the results have been excellent using Keihin mains and DJ needles and springs along with a BMC street air filter. I would also like to plug the front slide lift hole and see how she runs, and then possibly stagger the needle height.
As for the chart you referenced, I have absolutely no confidence in it's accuracy.
As best I can recall, the stock needle height corresponds to the #4 groove on the DJ needles. I will double check that when I have time.
07-03-2012 | 06:16 PM
#6
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SuperSport
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From: Toronto, Ontario, Canada
Yeah, pretty much figured that one. I figure I' try and make due with what I have for now. My VTR, and the parts VTR both have the same DJ kit in them...
Beerhunter, what jetting are you running?
-Is that 4th groove from the top, or from the bottom of the neede?
07-03-2012 | 07:08 PM
#7
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Superstock
Joined: Mar 2009
Posts: 277
From: south nj (philly area)
For stock springs and needles from the stealership it will cost less than $100 and the jets are cheap could probably get it all for that and go with 8541hawks carb set up and be done with it imho well worth it to not have to yank the carbs 10are times...
07-03-2012 | 07:13 PM
#8
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From: San Antonio, TX
Grooves are numbered from the top, 1 lean to 6 rich.
I just compared the DJ needle to stock. It matches up very close to the # 5 groove, maybe 5.1- 5.2. With the shim added, making it 5.5, the difference was too great.
I would think that with the stock filter, the #4 groove would still be the best starting point with the DJ needles. You could try going 4.5 on the rear, but this is only speculation since the DJ needles are the same front vs rear, whereas the stock needles are different front to rear.
Right now I have 170/180 main, 45 pilots, needles clipped #4, extra slide hole drilled on both with short springs. With this setup vs the larger mains and K&N, the lean to rich transition at 4k rpm seems to have vanished and the power delivery is linear. I experienced an unexpected wheelie at an RPM range with this setup, at the same conditions where the K&N with rich mains would flatten out a little and accelerate more mildly.
I just compared the DJ needle to stock. It matches up very close to the # 5 groove, maybe 5.1- 5.2. With the shim added, making it 5.5, the difference was too great.
I would think that with the stock filter, the #4 groove would still be the best starting point with the DJ needles. You could try going 4.5 on the rear, but this is only speculation since the DJ needles are the same front vs rear, whereas the stock needles are different front to rear.
Right now I have 170/180 main, 45 pilots, needles clipped #4, extra slide hole drilled on both with short springs. With this setup vs the larger mains and K&N, the lean to rich transition at 4k rpm seems to have vanished and the power delivery is linear. I experienced an unexpected wheelie at an RPM range with this setup, at the same conditions where the K&N with rich mains would flatten out a little and accelerate more mildly.
07-03-2012 | 07:58 PM
#9
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SuperSport
Joined: Aug 2010
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From: Toronto, Ontario, Canada
I've got very little into my hawk, so I'm trying to make due with what I have.
I will start looking around for a complete spare set of stock carbs (at $100, thats probably doeable).
If that waits until the off season, so be it.
I don't mind tinkering.
Thanks Beerhunter, that gives me a good starting point.
08-22-2012 | 07:22 PM
#10
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SuperSport
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From: Toronto, Ontario, Canada
Update:
So, heres where I'm at.
178, 180 main jets
48 pilots.
DJ needles at 4th position, 1 washer each
2 1/4 turns front
2 1/2 turns rear
slides drilled (previous owner)
short slide springs
POS K&N filter (picking up a new stock filter shortly...)
Its got a bit of a surge at 4,000 rpm, but other than that, seems very linear in the power delivery.
I might try plugging one of the drilled slide holes in the front carb when I swap a stock filter into it.
So, heres where I'm at.
178, 180 main jets
48 pilots.
DJ needles at 4th position, 1 washer each
2 1/4 turns front
2 1/2 turns rear
slides drilled (previous owner)
short slide springs
POS K&N filter (picking up a new stock filter shortly...)
Its got a bit of a surge at 4,000 rpm, but other than that, seems very linear in the power delivery.
I might try plugging one of the drilled slide holes in the front carb when I swap a stock filter into it.
09-10-2012 | 03:59 PM
#11
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Senior Member
SuperSport
Joined: Aug 2010
Posts: 506
From: Toronto, Ontario, Canada
After riding for a couple weeks with this setup, I can tell you, theres something quite wrong...
My guess is with the extra slide holes, and the short slide springs, the needles aren't pulling out of the mains enough in the midrange.
It runs well until just before 4,000rpm. 4-6,500 or so it surges under anything under full throttle.
If I'm on it up to redline, it seems alright... just cruising around is real annoying.
It is doing the "carb farts" alot more now.
I'm going to change the needle height back to the #2 position and see if that gets it on the mains earlier in the rev-range.
I'll be setting up my spare set of carbs as per 8541Hawk's carb setup sticky in the off season.
My guess is with the extra slide holes, and the short slide springs, the needles aren't pulling out of the mains enough in the midrange.
It runs well until just before 4,000rpm. 4-6,500 or so it surges under anything under full throttle.
If I'm on it up to redline, it seems alright... just cruising around is real annoying.
It is doing the "carb farts" alot more now.
I'm going to change the needle height back to the #2 position and see if that gets it on the mains earlier in the rev-range.
I'll be setting up my spare set of carbs as per 8541Hawk's carb setup sticky in the off season.
09-10-2012 | 08:40 PM
#12
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SuperBike
Joined: Oct 2007
Posts: 1,082
From: Menifee, CA
Dudes when are you going to figure it out, the Dyno Jet stuff doesn't work on the SH the Factory Pro is better, but 8541Hawks is better if not the best. If you read all of the post over the last 5 years I've been here it's like the old Einstein axiom, trying the same thing over and over again and expecting a different result is the definition of insanity. In my humble opinion.
Last edited by HRCA#1; 09-10-2012 at 08:46 PM.
09-12-2012 | 03:26 PM
#13
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SuperSport
Joined: Aug 2010
Posts: 506
From: Toronto, Ontario, Canada
I'm working with what I've got. Both my hawks have Dynojet kits in them. I'm going to switch it over in the off season, but in the mean time I want it running as decent as possible.
I'm at #2 position on the needles now. Pulls smoothe, about as good as its going to get with the DJ setup for now.
I'd rather ride the bike right now than wrench or wait on parts.
I'm at #2 position on the needles now. Pulls smoothe, about as good as its going to get with the DJ setup for now.
I'd rather ride the bike right now than wrench or wait on parts.
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