Slopeflyer
Junior Member
Two weeks ago I installed new plugs. Put about 200 miles on her. Want to check to see if I am running lean or rich. Pulled #4 plug and it is so clean it can't tell. Is it too soon?
It will only show the extremes and one could say inspection was good for carbs but the OEM ECU map coupled with the high compression and the heads chamber design, it burns pretty clean.
So, short of reading the O2 sensor output there isn't much to see while running stock hardware, Fuel Map, etc.
Mind you, even if you don't have an O2 sensor, you can weld in a bung, add a sensor and monitor it fairly inexpensively.
All though this is WB sensor, read up on o2 monitor Bar graph....
AutoSpeed - Monitoring Factory Oxygen Sensors, Part 2
AutoSpeed - Monitoring Factory Oxygen Sensors, Part 1
Bottom of this for Sensor Voltage output vs O2 content (AFR)
DIY Air / Fuel Ratio Meter
Another search option: Bar Graph AFR Meter
https://www.google.com/search?q=bar......1ac.1.34.heirloom-serp..19.0.0.Fdwbl4wdNvk
So, short of reading the O2 sensor output there isn't much to see while running stock hardware, Fuel Map, etc.
Mind you, even if you don't have an O2 sensor, you can weld in a bung, add a sensor and monitor it fairly inexpensively.
All though this is WB sensor, read up on o2 monitor Bar graph....
AutoSpeed - Monitoring Factory Oxygen Sensors, Part 2
AutoSpeed - Monitoring Factory Oxygen Sensors, Part 1
Bottom of this for Sensor Voltage output vs O2 content (AFR)
DIY Air / Fuel Ratio Meter
Another search option: Bar Graph AFR Meter
https://www.google.com/search?q=bar......1ac.1.34.heirloom-serp..19.0.0.Fdwbl4wdNvk
Slopeflyer
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As noted, you need some more miles on the plugs to get a long term good idea what's going on in the engine.
But, so far, those plugs looks fine.
How did the OLD plugs look? They would tell a story..
Re wanting to know if its running rich/lean, etc. What kinda of mileage (and if you have stock gearing, riding style) are you getting? If your 40+, closer to 50 MPG (US), your A/F should be good. 46-48 MPG seems to be most common on a stock, non PC'ed engine.
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Slopeflyer
Junior Member
Getting high fourtys after the T.B sync. But I messed with the #1 T.B. Screw. Don't know exactly where it should be set. So just wondering if it's running lean or rich.
Do you recall which way you ended up turning it?
If it idles well, takes off from idle and doesn't die its likely rich enough. If it were too lean it **could die* as soon as load is increased or vacuum drops from opening the throttle plates.
Do you have a vacuum gauge with actual values on it? Typically as the vacuum gets higher, its leaner. As the vacuum gets lower, its richer.
Spec:
Idling condition
Engine idling speed: 1250–1350 r/min
Intake vacuum: 29.0 kPa (8.6 inHg) (218 mmHg)
Water temperature: 95.0–105.0 °C (203.00–221.00 °F)
Connect a 'T' into the the vacuum sensor and run it to your gauge. Adjust all 4 screws equally to move it up and down.
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There is NO official setting documented anywhere. I did the same with mine (W/O first checking the # of turns out) trying to get the overall atmosphere pressure per the book (which really doesn't matter.......). Never happened and I am at sea level.
I did some looking on the internet and found un-officially, 1-1.25 turns out on #1 is fine. If you run out of adjustment on the others, OPEN #1 a little more. As long as the cylinders are pulling the same is what's important. The sync affects mostly the lower RPM range more(under approx 4K RPM's). If its way out, yes, you can get un-necessary vib's, etc..
Its not like an older carbed engine with a main jet too lean that you'll fry a piston at WOT.
I have mine at 1 turn out, runs great. Another member, also messed with his, set it at 1.25, runs fine too. If your getting high 40's, the engine runs good, you should be good.
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Slopeflyer
Junior Member
It's out about 1 1/2 turns. I am just worried about running to lean and frying the motor. I wish I would have never touched the #1 T.B screw. Bike runs good, idles good, and I get good gas mileage now. Maybe someday I will invest in a vacuum so I can get it to spec.
Slopeflyer
Junior Member
On 3-18 of the manual it says if the screw is removed turn in 3/4 and than re-sync the T.B. If I did that I would be worried it will vibrate out. I think I will just leave it alone.
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It sure is there, I didn't see it.
When I messed with mine, I was trying to get it to the SPECIFIED vacuum (at sea level yet) and couldn't get it close... That's with a Morgan Carbtune that is marked.
Ended up setting it at 1 turn out. Had plenty of adjustment with the other screws and was able to get all within 3mm's at idle and 4,000 RPM's.
Sounds to me like yours is fine.
Slopeflyer
Junior Member
Just wonder if it would run any better or be more responsive it we did that
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Just wonder if it would run any better or be more responsive it we did that
I couldn't get it to come close to the suggested #'s. You can try, but I suspect you'll be wasting your time (as I did)
I would just record what your good runnings #'s are RIGHT NOW, before changing them...
As long as their even (within spec's, the closer, the better). This is per the Carbtune manual, your good...
Slopeflyer
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Maybe next time I am under the tank and have time to tinker with it.
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I would be interested to see if you can find / feel any difference (performance, mileage, etc)... :thumbup:
Think about this: At idle the engine is using the least amount of fuel so this is going to have minimal if any impact to fuel economy unless you idle across town on a regular basis.
In this case we are adjusting the AIR VOLUME so as to achieve ~ 14.7:1 Air Fuel Ratio. Remember the fuel is injected at a Fixed rate for the RPM, Water Temperature, Air temperature and our atmospheric pressure (altitude). Old School carbs we adjusted the fuel amount, here we'd need to tamper with the fuel map to do that so they locked the fuel map and allowed us to change the air volume to achieve the desired idle speed and vacuum. Vacuum is reflective of load and burn mixture.
IMO - a 1/4 or 1/2 turn is not going to change the amount of fuel consumed but it may effect how well the engine responds from idle on up or when coming down from high RPM. I would default to RICH (i.e. 3/4 turns out as a starting point) as it will almost always perform better.
As I mentioned above, if you screw them all the way in, you could richen the mixture or all the way out and lean the mixture. Too rich and most won't notice anything. But to lean and it may stumble on take off, die when coming down from higher RPM, or cause detonation during take off up hill.
For those with S2's, tap into the O2 sensor and read the voltage as the ECM sees it. Roughly speaking if your DMM sees 0.570vDC on average, its ~ 14.7:1 AFR
1.0 - 0.97V - 12.1:1
0.88V - 12.7:1
0.78V - 13.2:1
0.69V - 13.8:1
0.59V - 14.4:1
0.56V - 14.8:1
0.54V - 15.2:1
0.39V - 15.4:1
0.30V - 16.0:1
0.20V - 16.5:1
0.10V - 17.1:1
Of course sensors are going to vary a little so this is a guide only.
JJD952 - tune
In this case we are adjusting the AIR VOLUME so as to achieve ~ 14.7:1 Air Fuel Ratio. Remember the fuel is injected at a Fixed rate for the RPM, Water Temperature, Air temperature and our atmospheric pressure (altitude). Old School carbs we adjusted the fuel amount, here we'd need to tamper with the fuel map to do that so they locked the fuel map and allowed us to change the air volume to achieve the desired idle speed and vacuum. Vacuum is reflective of load and burn mixture.
IMO - a 1/4 or 1/2 turn is not going to change the amount of fuel consumed but it may effect how well the engine responds from idle on up or when coming down from high RPM. I would default to RICH (i.e. 3/4 turns out as a starting point) as it will almost always perform better.
As I mentioned above, if you screw them all the way in, you could richen the mixture or all the way out and lean the mixture. Too rich and most won't notice anything. But to lean and it may stumble on take off, die when coming down from higher RPM, or cause detonation during take off up hill.
For those with S2's, tap into the O2 sensor and read the voltage as the ECM sees it. Roughly speaking if your DMM sees 0.570vDC on average, its ~ 14.7:1 AFR
1.0 - 0.97V - 12.1:1
0.88V - 12.7:1
0.78V - 13.2:1
0.69V - 13.8:1
0.59V - 14.4:1
0.56V - 14.8:1
0.54V - 15.2:1
0.39V - 15.4:1
0.30V - 16.0:1
0.20V - 16.5:1
0.10V - 17.1:1
Of course sensors are going to vary a little so this is a guide only.
JJD952 - tune
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