Need Some Carb Setup Insight
04-12-2013 | 01:04 PM
#1
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Posts: 267
Need Some Carb Setup Insight
ok here we go
2002 Hawk
Stock Filter
Short 2 Brothers Exhaust (cans are only 9in long)
Current Carb Setup
Factory Pro Titanium Jet Kit
180F / 182R
#50 Pilot Jet
Mixture Scew 1.5 Turns Out
Titanium Needles Clip Set At 2nd Notch
Bike Runs Great to 7k then Begins to cough and stutter while Stumbling up to red line
Anyone have some insight as to what needs to be done with the carbs i feel like its lean still and maybe starving for fuel at higher rpms
i did perform a carb sync while it made a small difference issue is still there, the petcock diaghfram is also new and the vacuum lines are all hooked up properly
thanks everyone
2002 Hawk
Stock Filter
Short 2 Brothers Exhaust (cans are only 9in long)
Current Carb Setup
Factory Pro Titanium Jet Kit
180F / 182R
#50 Pilot Jet
Mixture Scew 1.5 Turns Out
Titanium Needles Clip Set At 2nd Notch
Bike Runs Great to 7k then Begins to cough and stutter while Stumbling up to red line
Anyone have some insight as to what needs to be done with the carbs i feel like its lean still and maybe starving for fuel at higher rpms
i did perform a carb sync while it made a small difference issue is still there, the petcock diaghfram is also new and the vacuum lines are all hooked up properly
thanks everyone
04-12-2013 | 05:57 PM
#2
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Superstock
Joined: Oct 2011
Posts: 273
From: Pompano Beach, Fl.
Trial and Error
ok here we go
2002 Hawk
Stock Filter
Short 2 Brothers Exhaust (cans are only 9in long)
Current Carb Setup
Factory Pro Titanium Jet Kit
180F / 182R
#50 Pilot Jet
Mixture Scew 1.5 Turns Out
Titanium Needles Clip Set At 2nd Notch
Bike Runs Great to 7k then Begins to cough and stutter while Stumbling up to red line
Anyone have some insight as to what needs to be done with the carbs i feel like its lean still and maybe starving for fuel at higher rpms
i did perform a carb sync while it made a small difference issue is still there, the petcock diaghfram is also new and the vacuum lines are all hooked up properly
thanks everyone
2002 Hawk
Stock Filter
Short 2 Brothers Exhaust (cans are only 9in long)
Current Carb Setup
Factory Pro Titanium Jet Kit
180F / 182R
#50 Pilot Jet
Mixture Scew 1.5 Turns Out
Titanium Needles Clip Set At 2nd Notch
Bike Runs Great to 7k then Begins to cough and stutter while Stumbling up to red line
Anyone have some insight as to what needs to be done with the carbs i feel like its lean still and maybe starving for fuel at higher rpms
i did perform a carb sync while it made a small difference issue is still there, the petcock diaghfram is also new and the vacuum lines are all hooked up properly
thanks everyone
Since this is all trail and error I would try this. Drop the needle clips down 2 notches raising needles and retest. If it's better you're in the zone but if worse then you may have other issues.
04-13-2013 | 05:18 AM
#4
Thread Starter
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Posts: 267
What do the plugs look like? Personally I would think you are way rich right now Attachment 15375
04-16-2013 | 01:11 PM
#7
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OK here's some pics hopefully this works
https://docs.google.com/file/d/0B6_I...?usp=drive_web
https://docs.google.com/file/d/0B6_I...?usp=drive_web
Sorry it took a while
https://docs.google.com/file/d/0B6_I...?usp=drive_web
https://docs.google.com/file/d/0B6_I...?usp=drive_web
Sorry it took a while
Last edited by Billzilla15; 04-16-2013 at 02:36 PM.
04-16-2013 | 01:45 PM
#8
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SuperBike
Joined: Dec 2005
Posts: 1,689
From: South Lake Tahoe, CA, USA
What do the plugs look like? Personally I would think you are way rich right now Attachment 15375
Based on Mike's tuning advice and my experience, I would drop the pilots down to no more than #48 and you will likely end up going down in the main jets as well, then raising the needles to richen the midrange. But not with the main jets you have. You may be able to get the midrange to work, with the main jets you have, but the top end will probably still be fat.
at one time I had 180 and 185 jets, with #48 mains and the engine would fall on it's face at high altitude, above 7000 ft, so it was borderline too rich at low altitude and way too rich at altitude.
04-16-2013 | 01:53 PM
#9
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ok thanks let me know if you think this is a good starting point then
#48 Pilot Jet
#175 Front #178# Rear (or #178 front and #180 Rear)
Needle on #4 From the top (or #2 from the top)
Mixture Screws at 2 Out
i don't really know where to start with this so any info on a good base would be great
#48 Pilot Jet
#175 Front #178# Rear (or #178 front and #180 Rear)
Needle on #4 From the top (or #2 from the top)
Mixture Screws at 2 Out
i don't really know where to start with this so any info on a good base would be great
04-16-2013 | 02:12 PM
#10
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SuperBike
Joined: Dec 2005
Posts: 1,689
From: South Lake Tahoe, CA, USA
Well...
I used to think that going up in the main jets was required with an open exhaust, but again, with Mike's experince and my own set of after work carb tuning ("Are you working on that.. MOTORCYCLE again??), I would probably go back to 175 and 178, with #48 pilot jets, since the bigger pilots effect the top end as well.
I'm guessing start at notch 2 or 3, and see what happens in the low-midrange transition on to the needle progression. Fine tune form there.
Mr. 8541Hawk can correct me from there...
Also, use the idle screws to adjust the idle mixture, not to tune the top end.
I used to think that going up in the main jets was required with an open exhaust, but again, with Mike's experince and my own set of after work carb tuning ("Are you working on that.. MOTORCYCLE again??), I would probably go back to 175 and 178, with #48 pilot jets, since the bigger pilots effect the top end as well.
I'm guessing start at notch 2 or 3, and see what happens in the low-midrange transition on to the needle progression. Fine tune form there.
Mr. 8541Hawk can correct me from there...
Also, use the idle screws to adjust the idle mixture, not to tune the top end.
Last edited by RCVTR; 04-16-2013 at 02:14 PM.
04-16-2013 | 02:33 PM
#11
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Well...
I used to think that going up in the main jets was required with an open exhaust, but again, with Mike's experince and my own set of after work carb tuning ("Are you working on that.. MOTORCYCLE again??), I would probably go back to 175 and 178, with #48 pilot jets, since the bigger pilots effect the top end as well.
I'm guessing start at notch 2 or 3, and see what happens in the low-midrange transition on to the needle progression. Fine tune form there.
Mr. 8541Hawk can correct me from there...
Also, use the idle screws to adjust the idle mixture, not to tune the top end.
I used to think that going up in the main jets was required with an open exhaust, but again, with Mike's experince and my own set of after work carb tuning ("Are you working on that.. MOTORCYCLE again??), I would probably go back to 175 and 178, with #48 pilot jets, since the bigger pilots effect the top end as well.
I'm guessing start at notch 2 or 3, and see what happens in the low-midrange transition on to the needle progression. Fine tune form there.
Mr. 8541Hawk can correct me from there...
Also, use the idle screws to adjust the idle mixture, not to tune the top end.
04-16-2013 | 03:17 PM
#12
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Joined: Aug 2007
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From: Lake View Terrace, CA
Well...
I used to think that going up in the main jets was required with an open exhaust, but again, with Mike's experince and my own set of after work carb tuning ("Are you working on that.. MOTORCYCLE again??), I would probably go back to 175 and 178, with #48 pilot jets, since the bigger pilots effect the top end as well.
I'm guessing start at notch 2 or 3, and see what happens in the low-midrange transition on to the needle progression. Fine tune form there.
Mr. 8541Hawk can correct me from there...
Also, use the idle screws to adjust the idle mixture, not to tune the top end.
I used to think that going up in the main jets was required with an open exhaust, but again, with Mike's experince and my own set of after work carb tuning ("Are you working on that.. MOTORCYCLE again??), I would probably go back to 175 and 178, with #48 pilot jets, since the bigger pilots effect the top end as well.
I'm guessing start at notch 2 or 3, and see what happens in the low-midrange transition on to the needle progression. Fine tune form there.
Mr. 8541Hawk can correct me from there...
Also, use the idle screws to adjust the idle mixture, not to tune the top end.
What is there to correct... that is what I would do also.
The only other thing I would try is to run 2 shims on the rear needle and 1 shim on the front.
04-16-2013 | 03:21 PM
#13
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04-16-2013 | 03:30 PM
#14
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Joined: Dec 2005
Posts: 1,689
From: South Lake Tahoe, CA, USA
Think of slot position as a coarse adjustment, shims as a medium adjustment and pilot mixture screws as fine. One step at a time...
Mike's suggestion adds a bit more fuel to the rear.
Mike's suggestion adds a bit more fuel to the rear.
04-18-2013 | 03:10 PM
#16
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ok guys took all of your advice changed the jets 175 and 178 and *48 my needles are at the third notch and mixture screws are two out,
it ran Great no coughs or stutters just a smooth pull
it does however lack a lot of power am i to rich still? should i put the stock needles back in or just lean out the needles by a notch or maybe 2
it ran Great no coughs or stutters just a smooth pull
it does however lack a lot of power am i to rich still? should i put the stock needles back in or just lean out the needles by a notch or maybe 2
04-18-2013 | 03:43 PM
#17
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From: Lake View Terrace, CA
Another place to use the choke to figure out what you need to do....
After the bike is warmed up, just slightly open the choke (or enrichment circuit) and see how the bike runs.
Is it better? then you are lean.
Is it worse? then you are rich.
and go from there, though the closer you get the harder it will be to trouble shoot over the net.
I does come to a point where I need to ride the bike at times....
After the bike is warmed up, just slightly open the choke (or enrichment circuit) and see how the bike runs.
Is it better? then you are lean.
Is it worse? then you are rich.
and go from there, though the closer you get the harder it will be to trouble shoot over the net.
I does come to a point where I need to ride the bike at times....
04-26-2013 | 01:22 PM
#18
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Another place to use the choke to figure out what you need to do....
After the bike is warmed up, just slightly open the choke (or enrichment circuit) and see how the bike runs.
Is it better? then you are lean.
Is it worse? then you are rich.
and go from there, though the closer you get the harder it will be to trouble shoot over the net.
I does come to a point where I need to ride the bike at times....
After the bike is warmed up, just slightly open the choke (or enrichment circuit) and see how the bike runs.
Is it better? then you are lean.
Is it worse? then you are rich.
and go from there, though the closer you get the harder it will be to trouble shoot over the net.
I does come to a point where I need to ride the bike at times....
04-26-2013 | 02:27 PM
#19
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From: UK
it does however lack a lot of power am i to rich still? should i put the stock needles back in or just lean out the needles by a notch or maybe 2
As hawk said the closer you get the harder it is to troubleshoot as it gets harder to determine where in the circuit it may need tweaking.
You should have felt something from the choke test. Maybe you did not pull it out quite enough. But to be honest when it comes to fine tuning, the choke test gets a bit tricky. It's great when you are making course adjustments and need to know whether your lean or rich.
Quick question have you adjusted your TPS at all as FP recommend. This does make a difference to low speed idle and steady state cruise.
Have a read through the following thread as it will have some relevant info and some useful links that can help you determine which way need to go.
https://www.superhawkforum.com/forum...-carb-q-30114/
(:-})
04-26-2013 | 03:39 PM
#20
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From: Fulton, MO
Sounds like your initial guess of lean is correct, which is super surprising since you have #50 idle jets and sufficiently sized mains, and you're not at sea level to top it off. Check for vacuum leaks first and ensure the carbs are fully seated and the boots aren't cracked. If all looks SAT then move on with rejetting richer.
One other question: Is your airbox stock and unmodified (lid intact, no holes, snorkel installed)?
One other question: Is your airbox stock and unmodified (lid intact, no holes, snorkel installed)?
04-26-2013 | 04:27 PM
#21
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Sounds like your initial guess of lean is correct, which is super surprising since you have #50 idle jets and sufficiently sized mains, and you're not at sea level to top it off. Check for vacuum leaks first and ensure the carbs are fully seated and the boots aren't cracked. If all looks SAT then move on with rejetting richer.
One other question: Is your airbox stock and unmodified (lid intact, no holes, snorkel installed)?
One other question: Is your airbox stock and unmodified (lid intact, no holes, snorkel installed)?
04-26-2013 | 04:34 PM
#22
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Ah, gotcha. Just read the whole thread. Duh...
If it's not too much trouble I'd go up one size on the mains, to 178/180. Just my opinion.
How is cold starting? Also, you do realize this bike really has no top end hit, right? It's a very linear pull pretty much to redline. The first time I rode a Superhawk I was pulling onto the highway and rammed smack into the limiter because I was waiting for that pull. Well, you just won't get one with this animal. She's a different breed.
If it's not too much trouble I'd go up one size on the mains, to 178/180. Just my opinion.
How is cold starting? Also, you do realize this bike really has no top end hit, right? It's a very linear pull pretty much to redline. The first time I rode a Superhawk I was pulling onto the highway and rammed smack into the limiter because I was waiting for that pull. Well, you just won't get one with this animal. She's a different breed.
04-27-2013 | 12:00 PM
#23
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Ah, gotcha. Just read the whole thread. Duh...
If it's not too much trouble I'd go up one size on the mains, to 178/180. Just my opinion.
How is cold starting? Also, you do realize this bike really has no top end hit, right? It's a very linear pull pretty much to redline. The first time I rode a Superhawk I was pulling onto the highway and rammed smack into the limiter because I was waiting for that pull. Well, you just won't get one with this animal. She's a different breed.
If it's not too much trouble I'd go up one size on the mains, to 178/180. Just my opinion.
How is cold starting? Also, you do realize this bike really has no top end hit, right? It's a very linear pull pretty much to redline. The first time I rode a Superhawk I was pulling onto the highway and rammed smack into the limiter because I was waiting for that pull. Well, you just won't get one with this animal. She's a different breed.
Last edited by Billzilla15; 04-29-2013 at 07:02 AM. Reason: i cant spell
04-27-2013 | 12:22 PM
#24
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As you said opening the choke did nothing, personally I would start with the choke cable.
Does it move smoothly and stay open or is it hard to pull and wants to close by itself?
If it doesn't move smoothly check the cables and the tube where it splits from one to two.
If the end caps on that tube are not seated or the cable is hanging up then the enrichment needles might be sticking open.
Does it move smoothly and stay open or is it hard to pull and wants to close by itself?
If it doesn't move smoothly check the cables and the tube where it splits from one to two.
If the end caps on that tube are not seated or the cable is hanging up then the enrichment needles might be sticking open.
04-29-2013 | 07:03 AM
#25
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As you said opening the choke did nothing, personally I would start with the choke cable.
Does it move smoothly and stay open or is it hard to pull and wants to close by itself?
If it doesn't move smoothly check the cables and the tube where it splits from one to two.
If the end caps on that tube are not seated or the cable is hanging up then the enrichment needles might be sticking open.
Does it move smoothly and stay open or is it hard to pull and wants to close by itself?
If it doesn't move smoothly check the cables and the tube where it splits from one to two.
If the end caps on that tube are not seated or the cable is hanging up then the enrichment needles might be sticking open.
04-29-2013 | 01:41 PM
#29
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From: Snohomish, WA.
Another thought, you might want to try a flo-commander as some of us have for fine tuning, rather than use the choke. It's pretty much what they are for, IMHO. But, the choke is cheaper and you don't have to wait for/install etc.
04-30-2013 | 07:44 AM
#30
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well that was easy, thanks guys i would have never figured that out, ok so now the choke is staying open, and i know that its working because when i cold start it the choke open engine rpms are up and if its still cold and i close the choke it almost dies, so if that's working why wouldn't i see a difference when riding it. my thought (im probably wrong) is that im rich already and opening the choke is just making it richer therefore im not noticing any difference, so im thinking im going to go up a notch on the needle and try that(im on the third notch so up to lean it out). Thoughts
