 Re: CV Carb Tuning
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Joined: Feb 2008
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Pilot screws are now about 2&5/8 turns out. No other changes. It idles happier & some very minor very rare carb spitting is gone. Cruise is good. I think the carbs are now adapted to the v-stacks. A bit more work than I imagined, but worth it, IMO.
These carbs still have the original D screws. FWIW, when adjusting D screws I have found it more accurate to use the fully closed & out method. When I have done it differently the setting are usually off.
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Re: CV Carb Tuning
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Joined: Apr 2008
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Loquacious
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 Where do you live Ken? I sure don't have the time, knowledge, or patience to even START to attempt what you've done, but I'd pay a little somep'in' somep'in' for it.  
And you may see me tonight
With an illegal smile
J. Prine
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Re: CV Carb Tuning
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Joined: Feb 2008
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Quote:
...Where do you live Ken? ...
Eastern PA.
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Re: CV Carb Tuning
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Joined: Aug 2009
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Learned Hand
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Learned Hand
Joined: Aug 2009
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Ken, sir, you are the deffinition of a "Tuner & Tweeker" Well done!!  I agree with Ryk and Erle, I sure could use the help and a book would be great! 
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Re: CV Carb Tuning
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Joined: Apr 2008
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Loquacious
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Loquacious
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Ya know Matt, THIS THREAD could be that "book" your thinkin' about! 
And you may see me tonight
With an illegal smile
J. Prine
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Quote:
Quote:
You will have change something and get it out of tune, so you will have something to work out...
Well, there is still the air cut valve (ACV). My theory is that sometimes the ACV closes under acceleration & causes a temporary rich mixture; more preload or a stronger spring rate should mitigate that. See, I'm not done yet
Ryk, you don't know how true your comment was.
Here's what I've learned about the ACV so far:
A washer with a minimum ID of 8mm and a maximum OD of 14mm will fit in the ACV cap for ACV diaphram preload. I had 1 such washer on hand, 1.2mm thick.
The ACV diaphram coil spring is pretty stout. It measures 48.5mm OAL, .9mm wire diameter, 13.3mm outer diameter, 7 active coils, 9 coils total.
With the 1.2mm thick spacer, the decel AFR's went about a full point (a full whole number) leaner. Curiously, WOT was about half a point richer. I thought that was a fluke.
Next trial was to totally take the ACV vacuum channel out of the picture by removing the O ring and plugging the channel with a small custom-cut rubber "stopper" made from a rubber autobody panel insert. I also removed the spring shim, & left the diaphram & stock spring in.
With the ACV vacuum channel blocked off decel is about 2 full points leaner, & WOT is about 3/4 of a point richer. Somehow the ACV mods are also affecting WOT to a small degree. Not sure why just yet.
Light throttle acceleration response is sharper with the ACV full vacuum channel block mod, however at a cost of a bit more decel popping. It is not objectionable.
It looks like the mains will need to drop from 150's to 148's in order to compensate for the blocked ACV channel. I will order 148's & retest.
The ACV vacuum block mod is completely reversible by pulling the ACV cover, removing the rubber stopper, and replacing the O-ring (it's about 2mm thick & looks more like a grommet than a true O-ring).
Keep in mind the ACV cover is under spring pressure, so keep thumb pressure on it while removing/replacing the screws.
Some of the dual-sport thumper guys with CV carb/s mod the ACV so it cuts pilot air all the time, however I don't see any advantage to doing it that way.
I'm not sure yet if the OEM ACV configuration or the blocked vacuum channel will prove to be best, however I don't think I'll use the ACV spring preload washer again. All in or all out, & tune accordingly.
Now the wait for those K OEM 148 mains... 
And some pics to follow when I get some time to post them.
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Re: CV Carb Tuning
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Joined: Feb 2008
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The 148 main jets arrived today. I installed them after dinner. I was surprised that the motor is still running a bit rich WOT with the 148 jets, however it was a super hot day, & the 148s should run closer to optimal in cooler weather. I suppose I could try 145 mains. I don't have any OEM 145 mains on-hand, however I do have a set of AB 145 mains.
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Re: CV Carb Tuning
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Joined: Apr 2008
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Loquacious
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Loquacious
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Quote:
I don't have any OEM 145 mains on-hand, however I do have a set of AB 145 mains.
Decisions, decisions!
You GO boy!!!
And you may see me tonight
With an illegal smile
J. Prine
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Here is the latest: 07 SM 865/270 Stock heads & pistons TPUSA 813 cams TPUSA +3 Pieman Igniter PVL (Nology) coils IX plugs & TPUSA Magnecor wires Chevy 605 pipes with large G-Pop supplemental baffles Very mild intake spacer port-match cleanup Uni UP4229 pods mounted on modified Mikuni RS "50mm" de-horned velocity stacks (41mm OAL on the modded v-stacks) ACV port plugged Keihin OEM 148 mains NBZT needles, no shims Yamaha FZ1 Vacuum piston slide springs, cut to 88.9mm/3.5" OAL Polished slides, slide vacuum port air holes drilled to 2.53mm (#39WG drill bit) 1.2mm throttle plate butterfly air bleed holes (close to optimal, IMO) 18.5+mm (or so) float heights (fuel level below gasket surface) Keyster 40 pilot jets Pilot screws about 2.6+ turns out Sunoco 87 non-E gas + a splash of Lucas Octane Booster I'm gonna keep the 148 mains. For now. After I get the Barnett green clutch springs in, back to the dyno.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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On my last 300+ mile ride, I went 170 miles before the other guys I was riding with needed to stop for fuel, so when we stopped I refueled too...& I hadn't even flipped to reserve yet...I somehow managed to spill gas everywhere (which is another story), so I couldn't get an accurate MPG figure for that fill. When I got home I topped the tank from portable cans (non-E ain't easy to come by), so again, no accurate measure. That said, the bike is getting more than 55 MPG on trips...
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Re: CV Carb Tuning
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Joined: Aug 2009
Posts: 1,669
Learned Hand
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Learned Hand
Joined: Aug 2009
Posts: 1,669 |
VERY ENVIOUS NOW. 
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Got the Barnett green clutch springs in today. The clutch feels noticeably more positive now.
I have my eye on the BC billet intake manifolds, however I want to get the bike to the dyno before any other changes. That said, I don't expect the replacement manifolds to make any more power.
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Re: CV Carb Tuning
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Joined: Aug 2007
Posts: 10,715 Likes: 4
Should be Riding
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Should be Riding
Joined: Aug 2007
Posts: 10,715 Likes: 4 |
my manifolds made like 5 ftlbs more torque if I remember right, but they might be slightly different than the BC ones
Always remember to be yourself. Unless you suck. Then pretend to be someone else.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Yours are FF ported manifolds on a 904, correct?
If the BC manifolds make anything more on my 865 I'll be way impressed.
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Re: CV Carb Tuning
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Joined: Aug 2007
Posts: 10,715 Likes: 4
Should be Riding
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Should be Riding
Joined: Aug 2007
Posts: 10,715 Likes: 4 |
yeah, but I had dyno runs with the 904, then again with the bored carbs, then again with the intakes so I have to believe that its a true representation of power added
Always remember to be yourself. Unless you suck. Then pretend to be someone else.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Didn't get to the dyno yet, however on my last 124 mile trip, re-filled from the same pump, the bike did 56.3 MPG; mostly 2-lane, just riding along.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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I received the BC manifolds; nice looking pieces. Now I just need a warm enough day & some time to install 'em...
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Here's a link to a separate thread about the above BC Billet Intake Manifolds: BC Intake Manifold ThreadDJ Dyno here I come, Right back where I started from...
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Re: CV Carb Tuning
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Joined: Feb 2008
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Well, so far, so good. Initial test run shows no weird issues or apparent manifold leaks.
Main jets look OK.
Needles look OK.
Pilot screws need to richen up a bit.
Since the last dyno run I've made the following changes:
Tuned for Non-E gas (downsized mains)
Optimized the slide springs
Optimized the throttle plate air bleeds
Installed modded V-stacks
Plugged ACV
Installed BC manifolds
Light clean up of head intake casting
More changes than I normally make between runs. Oils well that ends well. Nyuk-nyuk-nyuk...
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Re: CV Carb Tuning
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Joined: Feb 2008
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Pilot screws are now at 3 turns out, bike runs strong.
Given that I changed the manifolds I want to check carb sync before returning to the dyno.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Went to 150 mains, as the bike was running leaner WOT with the BC manifolds. Pilot screws currently 2&7/8 out, and they can go a bit leaner with the new mains. Didn't get a chance yet to really test it the way I want.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Pilot screws are now about 2.6 turns out. That is the leanest I want to take them. No carb spitting. Still need to check carb sync.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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I swapped pipes for a set of de-restricted short tapered TORS...also have a new ignition sensor now running a narrower air gap...with no other changes, the bike was popping like crazy on decel.
So...pilot screws are now 2.75 turn out, and the ACV is re-enabled; those two actions substantially reduced the decel popping.
I may also try disconnecting the TPS. We'll see.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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I disconnected the TPS tonight, went for my usual 20 mile test ride, & that made a minor improvement in decel popping.
The real benefit though was a more stable AFR on acceleration. The bike starts and idles well, too. Cruise AFR is just as stable as before, if not more so. The bike seems to pull harder at lower RPMs, also.
So far, no downside to running the full advance, full time. I might even get a block-off plate for the TPS, as I like the disconnect so well that I doubt I'll use the TPS again. So far, disconnecting the TPS is all good.
Here is the latest:
07 SM 865/270
Stock heads & pistons
TPUSA 813 cams
TPUSA +3 Pieman Igniter
TPS disconnected
PVL (Nology) coils
IX plugs & TPUSA Magnecor wires
Short tapered TORS, inlet derestricted
BC intake manifolds
Uni UP4229 pods mounted on modified Mikuni RS "50mm" de-horned velocity stacks (41mm OAL on the modded v-stacks)
Keihin OEM 150 mains
NBZT needles, no shims
Yamaha FZ1 Vacuum piston slide springs, cut to 88.9mm/3.5" OAL
Polished slides, slide vacuum port air holes drilled to 2.53mm (#39WG drill bit)
1.2mm throttle plate butterfly air bleed holes (close to optimal, IMO)
18.5+mm (or so) float heights (fuel level below gasket surface)
Keyster 40 pilot jets
Pilot screws about 2.75 turns out
Sunoco 87 non-E gas + a splash of Lucas Octane Booster
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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I'm linking to my ignition sensor thread regarding the decel popping issue...looks like it might have been an exhaust air leak after all... Ignition Sensor Thread
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Still popping more than I prefer on decel, at low revs. Could be a crossover exhaust leak.
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Re: CV Carb Tuning
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I went through the whole exhaust system & the decel pop issue continues...so...today I went through the whole intake system, even replaced the BC billet intake manifolds with the OEM intake manifolds & spacers...while I was at it, I did some mild port-matching (more smoothing than matching) on the OEM spacers & manifolds.
I'll test tomorrow in daylight.
Just for kicks I reconnected the TPS.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Well, my happy motor is back.
Here is the latest:
07 SM 865/270
Stock heads & pistons
TPUSA 813 cams
TPUSA/TTP +3 8250 RPM "Pieman" Igniter
PVL (Nology) coils
IX plugs & TPUSA Magnecor wires
Short tapered TORS, inlet derestricted
OEM intake manifolds & spacers, lightly ported
Uni UP4229 pods mounted on modified Mikuni RS "50mm" de-horned velocity stacks (41mm OAL on the modded v-stacks)
TPS connected
ACV enabled
Keihin OEM 150 mains
NBZT needles, no shims
Keyster 40 pilot jets
Pilot screws about 3 turns out
Yamaha FZ1 Vacuum piston slide springs, cut to 88.9mm/3.5" OAL
Polished slides, slide vacuum port air holes drilled to 2.53mm (#39WG drill bit)
1.2mm throttle plate butterfly air bleed holes
18.5mm (or so) float heights (fuel level below gasket surface)
Sunoco 87 non-E gas + a splash of Lucas Octane Booster
Last edited by B02S4; 09/27/2014 5:17 PM.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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I will continue to run with the TPS, as I like the way the motor responds to the enrichener better with the TPS connected, than not.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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With the "new" intake I went with 3 turns out on the pilot screws to get better idle & cruise AFRs.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Hmmm...bike was getting variable AFR's at idle, outside of what I would consider normal. I rechecked the pilot screw settings and the starboard side was only about 2.5 out.
Given that the weather is now cooler, a little more out on the pilots is OK, so I went with 3.5 turns out. Idle AFR's on a warm motor were in the low 12's & much more stable, & hiway flat cruise was in the low 14's, about where I want it.
I also checked & adjusted carb sync, it was only out a little. Not bad considering some port-smoothing was done.
I consider the bike dyno-ready now.
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Re: CV Carb Tuning
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Joined: Feb 2008
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I called my usual dyno operator to get an updated run done today, & was told "can't do till next week"...ugh.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Got an updated dyno run today, with the current tuning configuration...not an optimal dyno testing weather day, as winds were gusting and BP was falling, but hey, it was dry, and I had to get it done while I had the time. Current tuning: 07 SM 865/270 Stock heads & pistons TPUSA 813 cams TPUSA/TTP +3 8250 RPM "Pieman" Igniter PVL (Nology) coils IX plugs & TPUSA Magnecor wires Short tapered TORS, inlet derestricted OEM intake manifolds & spacers, lightly ported Uni UP4229 pods mounted on modified Mikuni RS "50mm" de-horned velocity stacks (41mm OAL on the modded v-stacks) TPS connected ACV enabled Keihin OEM 150 mains NBZT needles, no shims Keyster 40 pilot jets Pilot screws about 3&1/3 turns out port side, about 3&3/4 turns out starboard side Yamaha FZ1 Vacuum piston slide springs, cut to 88.9mm/3.5" OAL Polished slides, slide vacuum port air holes drilled to 2.53mm (#39WG drill bit) 1.2mm throttle plate butterfly air bleed holes 18.5mm (or so) float heights (fuel level below gasket surface) Sunoco 87 non-E gas + a splash of Lucas Octane Booster Dyno sheet:  The guy who did the testing wasn't the usual tech; I wasn't able to see how he ran the throttle, however just by listening to the way the motor spooled up, I don't think he followed my instructions of being smooth on the roll-on...it sounded to me like he whacked it open. It matters. That said, I accomplished what I wanted from the run. The pipes are different from the prior run posted above, and some of the carb tuning parameters are different. The TORS enable a little more mid-range, at the cost of a little peak power. The numbers are hard to read in the image, so here they are in text: Max SAE corrected HP: 68.40 (down from prior run) Max SAE corrected TQ: 50.43 (up from prior run) Why are "red" and "blue" runs shown? That's just the way the dyno operator printed it...bike was tuned the same for both runs, & as a practical matter the outcomes are the same...DJ dynos have a range of "repeatability"...multiple runs are not expected to be identical, however, once the motor is up to temperature, all other things equal, the runs ought to be similar. What the dyno doesn't show is the qualitative performance of what from my perspective is excellent balance of performance, fast starts, quick warm-up, great driveability, & excellent fuel economy. I have another set of custom long stainless pipes that I want to test, which I think can do better on the top end, without hurting midrange. Just need to find the right baffles first...
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Re: CV Carb Tuning
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Joined: May 2010
Posts: 5,720
Check Pants
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Check Pants
Joined: May 2010
Posts: 5,720 |
Very respectable numbers for stock head and pistons.
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Re: CV Carb Tuning
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Joined: Feb 2008
Posts: 2,671 Likes: 15
Loquacious
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Loquacious
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Thanks. I also have an idea to try with the BC intake manifolds with a modified OEM 865 intake spacer.
I also suspect a potential leak with the starboard side pilot screw O ring...gonna check into that too.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Loquacious
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Current tuning: 07 SM 865/270 Stock heads & pistons TPUSA 813 cams (Gen 1) TPUSA/TTP +3 8250 RPM "Pieman" Igniter PVL (Nology) coils IX plugs & TPUSA Magnecor wires Short tapered TORS, inlets derestricted BC intake manifolds, with heads port-matched to intake manifolds Uni UP4229 pods mounted on modified Mikuni RS "50mm" de-horned velocity stacks (41mm OAL on the modded v-stacks) TPS connected ACV enabled Keihin OEM 150 mains NBZT needles, no shims Keyster 40 pilot jets Pilot screws about 3&1/3 turns out port side, about 3&7/8 turns out starboard side Yamaha FZ1 Vacuum piston slide springs, cut to 88.9mm/3.5" OAL Polished slides, slide vacuum port air holes drilled to 2.53mm (#39WG drill bit) 1.2mm throttle plate butterfly air bleed holes 18.5mm (or so) float heights (fuel level below gasket surface) Sunoco 87 non-E gas + a splash of Lucas Octane Booster Motor feels strong, bike is dyno ready. I also tested TPS circuit resistance & got the following results @ WOT: Blue & yellow: 1.38 Black & yellow: 3.80 Still at the factory setting
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Re: CV Carb Tuning
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Joined: Oct 2012
Posts: 459 Likes: 1
Adjunct
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Adjunct
Joined: Oct 2012
Posts: 459 Likes: 1 |
I'm anxiously awaiting your results. I refer to this thread constantly.
2006 865 Neon Blue/Jet Black Speedmaster,790cams, TTP Stage 2 Firestarter, Epco Exhaust with 10.25" Samson Vrod baffles, UNI pods with 40 pilots, 150 mains,Thruxton needles, 3 turns out.
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Re: CV Carb Tuning
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Joined: Mar 2013
Posts: 29
Greenhorn
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Greenhorn
Joined: Mar 2013
Posts: 29 |
Same feeling as being little and waiting for christmas!
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Quote:
I'm anxiously awaiting your results. I refer to this thread constantly.
It might take a couple of weeks until I get the time to do it.
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Re: CV Carb Tuning
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Joined: Feb 2008
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Loquacious
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Perfect dyno weather today, & my go-to shops can't accomodate... 
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