What do you think of my plugs??
Extreme HDF Member
Joined: Jun 2011
Posts: 10,216
Likes: 224
From: Glendale AZ
The slip- ons do and did have an effect if you compare the two plugs. Mine stopped looking like that after I put my tuner in with a modest fuel adjustment. Many say you cant go by the look because of the junk they put in fuel, but why would enriching the mixture in the mid ranges change the color of the plug if you cant go by the plug? What do I know?
Stellar HDF Member
Joined: Jun 2007
Posts: 2,178
Likes: 600
From: SoCal.....I'm only here for the weather
They look lean to me, and yes, to check a plug correctly you run it to cruising rpm, pull the clutch in and kill it, idling gives a false reading, thats what we do in our race car, run a few laps, at 7,000 rpm put it in neautral and kill the engine, coast into the pits and check the plugs.
Road Warrior
Joined: May 2010
Posts: 1,377
Likes: 20
From: Kafar Hanusi
mechanics is mechanics, if its lean then ya know what, its lean. that you can not adjust it doesn't mean your wrong it just means you need to spend money to add on a tool to adjust it.
If you do you can fix the problem, you may start down an expensive road when you do this then you need this and that but that means need to change C which means DYNo checks and more adjustments.
Do yourself a flavor, get a 6 pack and think'bout it sum.
If you do you can fix the problem, you may start down an expensive road when you do this then you need this and that but that means need to change C which means DYNo checks and more adjustments.
Do yourself a flavor, get a 6 pack and think'bout it sum.
Tourer
Joined: Nov 2007
Posts: 285
Likes: 3
From: Parkton,MD.
With today's ignition systems, reading plugs has pretty much gone the way of the dinosaur, not much value in it unless there is something seriously wrong. If you were to read plugs, the proper way is to put in brand new plugs, start it, ride it to the RPM range in question, pull in the clutch, hit the kill switch and coast to a stop. Then pull the plugs and read them. Back in the days when you did read plugs, saw many, many guys rode the bike a few minutes, rode it back home, pull the plugs and say, oh no, I'm lean. Then they would add fuel to the primary circuit, bike would run worse, but plugs still showed lean. Sooooo, more fuel in the primary circuit. All the time, the problem was the idle circuit was lean, by riding the bike back home, idling in the drive before shutting it off gave them a false reading. There is far better technology today to tell you how your engine is running than viewing a spark plug by eye. Just my opinion, use it as you will ......
I'm not a tech Frog 13 but I've had six Harley's and have ridden bikes for years. I too agree that plug reading is a thing of the past. After a hard ride and bike has cooled down I have just used my finger to swab a sample from each exhaust pipe and look for a nice gray residue rather than a rich black color or a lean tan one. You being a technician would you comment as to the validity of this as a simple lean/rich test? Thx.
Grand HDF Member
Joined: May 2006
Posts: 3,636
Likes: 1,207
From: Ohio
I am not a mechanic so take what I say with a grain of salt. I have owned and wrenched on 7 Harleys. IMHO...these air cooled motors need to run a little rich. There is no way in hell I would open the exhaust pipes without adding fuel. These bikes are already too lean from the factory as evidenced by the extreme heat. The EFI system is narrow band and IMHO is not suited to correct for exhaust and other changes. You have no idea of knowing what your true AF ratio is under varying RPMs, throttle position and loads. Why spend $20K on a bike and cheap out on the Stage 1? Add an air cleaner and good fuel management system and not only cool the bike down but pick up cheap HP and TQ. in the process.
Outstanding HDF Member
Joined: Nov 2008
Posts: 2,034
Likes: 127
I too am in the club that agrees that you can not put to much into plug readings today. What with the ethanol additives and such, gasoline just does not burn like it used to in days gone past. If you are used to reading plugs from years ago, todays plugs with fuel injection will look to be awfully lean to you. In fact they are not. I wholeheartedly agree with the gentleman who said a swipe of the finger inside of a muffler will tell you more about the air/fuel mixture than reading the plugs will. A correctly tuned fuel injection engine will have have a very light coating of black soot on the inside of the muffler, not a thick, heavy coat which you will have to scrub off your finger. Things change. Ya, they do.
Road Captain
Joined: Jun 2008
Posts: 507
Likes: 3
From: 2 miles from the Sun!
my plug pics
KEVFLHX11
Here are my plugs 05 flht carb bike I still think that I'm a little lean here. When I get cought at some traffic lites I get a little pinging. I think the things have change somewhat with the blended fuels ,it's still a combustion engine and weather you play Dr. procto or look at your plugs you will still get an idea of how your motor is running.
Left plug rear cylinder.
Here are my plugs 05 flht carb bike I still think that I'm a little lean here. When I get cought at some traffic lites I get a little pinging. I think the things have change somewhat with the blended fuels ,it's still a combustion engine and weather you play Dr. procto or look at your plugs you will still get an idea of how your motor is running.
Left plug rear cylinder.
Road Captain
Joined: Dec 2009
Posts: 570
Likes: 4
From: New Mexico
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Outstanding HDF Member
Joined: Jan 2010
Posts: 2,916
Likes: 31
From: earth
This is one of those topics that will never be widely acknowledged. You cannot "read" plugs in an EFI application. Exhaust gas analysis is the ONLY reliable method of determining tune condition. The factory tune is not lean, but it is very near stoichiometric AFR in the cruise range.
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