Spark plug Check

[dubepj]

I've heard that to check spark plugs correctly for lean/rich conditions it should be done just after a ride so they are hot. 
Why it that??  i would prefer check checking when cold to avoid burns.

[Burnout]

Reading spark plugs is not a difinative thing, there is not a whole lot of info there that does not show up in other areas.

Today's pump gas does not color the plug as leaded gas did.

When looking at plugs, you are looking for signs of badness more than anything else.

[Hossamania]

The best way to check plugs is while running with an afr meter.

[Deye76]

If your going to pull plugs on a hot motor, make sure they have some copper anti-seize on the threads before doing so.

[david lee]

dont you check plugs hot when determaning what main jet size to use

[Hossamania]

dont you check plugs hot when determaning what main jet size to use

Reading spark plugs is not a difinative thing, there is not a whole lot of info there that does not show up in other areas.

Today's pump gas does not color the plug as leaded gas did.

When looking at plugs, you are looking for signs of badness more than anything else.

In the good old days of lead gas, it was possible to read plugs to determine jet size, somewhat. Not an exact science, and took some experience. With today's unleaded fuel, it's pretty tough to do.
Get an afr meter.

[Hossamania]

Yes. I don't know a specific model, and that one may work, but that is the concept.

[Burnout]

http://www.daytona-sensors.com/wego--systems.html

I have a dual unit that includes logging.

You have to be fairly committed as you will need to weld bungs into the exhaust for the sensors. I recommend using long bungs, many supply only short ones.

[Deye76]

A good dyno tuner can assist with jetting.

[turboprop]

I've heard that to check spark plugs correctly for lean/rich conditions it should be done just after a ride so they are hot. 
Why it that??  i would prefer check checking when cold to avoid burns.

Lots of noise here. This evo of yours most likely has a recipe that's been done thousands of times and has known jetting and timing requirements. if it has a carb, it is not that complex. The arm chair crowd will chime in with noise about various things, but in the end they really mean nothing for a typical street evo build.

Try this, list as many details about your engine and the chassis (lightweight dyna or heavy barge bagger), and ask for known jetting combinations. Pay attention to the guys that have been tuning bikes for a while and be forewarned that many that respond will be either shooting from the hip or regurgitating something they read online.

[kd]

Good advice there.

[xlfan]

http://www.daytona-sensors.com/wego--systems.html

I have a dual unit that includes logging.

You have to be fairly committed as you will need to weld bungs into the exhaust for the sensors. I recommend using long bungs, many supply only short ones.

Is the long bungs for less zirconium exposure, or less flow resistance?

[JW113]

Spark plugs can be used for a general diagnostic measure for certain problems. If they're dry and jet black, obviously too rich. If they're caked with gooey sludge, you have an oil problem. Et certera, et cetera. As already mentioned, reading plugs for A/F ratio has gotten a lot harder. I think you can still use the plugs, along other visual/behavioral indicators, to get a carb jetted to run "good enough", but as I've found out, without a AFR meter, pretty hard to dial it in dead nuts on. And yes, love the Daytona Sensors WEGO unit.

-JW

[david lee]

Spark plugs can be used for a general diagnostic measure for certain problems. If they're dry and jet black, obviously too rich. If they're caked with gooey sludge, you have an oil problem. Et certera, et cetera. As already mentioned, reading plugs for A/F ratio has gotten a lot harder. I think you can still use the plugs, along other visual/behavioral indicators, to get a carb jetted to run "good enough", but as I've found out, without a AFR meter, pretty hard to dial it in dead nuts on. And yes, love the Daytona Sensors WEGO unit.

-JW

have you used gordons color tune

[SP33DY]

have you used gordons color tune

It's Gunson Colortune

[Wookie3011]

I found thin video very informative. GMR, Baxter, Tatro and George Bryce all are great to watch!! Any others I'm missing? I know there has to be a few more. Anywho, its something.

[turboprop]

Spark plugs can be used for a general diagnostic measure for certain problems. If they're dry and jet black, obviously too rich. If they're caked with gooey sludge, you have an oil problem. Et certera, et cetera. As already mentioned, reading plugs for A/F ratio has gotten a lot harder. I think you can still use the plugs, along other visual/behavioral indicators, to get a carb jetted to run "good enough", but as I've found out, without a AFR meter, pretty hard to dial it in dead nuts on. And yes, love the Daytona Sensors WEGO unit.

-JW

I remember telling you to try this and you getting pissed at me. Very happy to see you are a believer. Not sure how I ever tuned a carb without one. Seriously.

To add to the fun, I have, like everyone else, a bunch of friends that have been tuning carbs by ear and seat of their pants since gasoline was invented. They know everything. Don't need no stinking gauge, etc. I had a $100 challenge going for a while. Bring a bike to my garage, adjust the idle AFR to be optimal and then let me put my sniffer up the pipe. Have never seen a bike adjusted by an expert that was anywhere close to 12.5-14:1 AFR. Most were typically around 10:1 some where dangerously lean. Most were amazed at the precision of the AFR gauge and how such a small rotation could have such a drastic affect on the AFR. Most were reluctant to admit that learning occurred. Fun times.

[Breeze]

" Have never seen a bike adjusted by an expert that was anywhere close to 12.5-14:1 AFR. Most were typically around 10:1 some where dangerously lean."

? 10:1 dangerously LEAN???

[Hossamania]

" Have never seen a bike adjusted by an expert that was anywhere close to 12.5-14:1 AFR. Most were typically around 10:1 some where dangerously lean."

? 10:1 dangerously LEAN???

Two different statements being made. Most were rich at 10:1, some were dangerously lean.

[Breeze]

^^^^^^^^^^ Rereading it this morning I see my error.  I read it several times yesterday but my mind kept seeing it wrong. Damn oldtimers. Thanks

[turboprop]

" Have never seen a bike adjusted by an expert that was anywhere close to 12.5-14:1 AFR. Most were typically around 10:1 some where dangerously lean."

? 10:1 dangerously LEAN???

Yes, Most were around 10:1, while others were dangerously lean. By that I mean 15:1 or higher.

[mkd]

i got all about the powercommander that was on my bike yrs ago and decided to do a few spark plug checks. did never find out too much but i did manage to bugger the threads up pulling plugs on my 2005 eglide efi. back plug was stiff all the way out and all the way in for ever after. I learned a hard lesson pulling plugs with a hot engine.

[Burnout]

A touch of never-seize goes a long way.

[Ironheadmike]

Spark plugs can tell you a lot . Fuel mixture,the correct timing, also if you have bad rings or valves . If you use never seize you will muck up some of the readings . Also NEVER take a plug out of a hot motor . You will risk of pulling to threads out . Remember aluminum is soft when it is hot .

[Hossamania]

Spark plugs can tell you a lot . Fuel mixture,the correct timing, also if you have bad rings or valves . If you use never seize you will muck up some of the readings . Also NEVER take a plug out of a hot motor . You will risk of pulling to threads out . Remember aluminum is soft when it is hot .

How does never seize muck up the readings?

[david lee]

Spark plugs can tell you a lot . Fuel mixture,the correct timing, also if you have bad rings or valves . If you use never seize you will muck up some of the readings . Also NEVER take a plug out of a hot motor . You will risk of pulling to threads out . Remember aluminum is soft when it is hot .

How does never seize muck up the readings?

never knew that.how would you check main jet size. ive read that you supose to ride down the highway at a certain speed,hit the kill switch, pull the plugs and check color ?

[Ironheadmike]

If you cover the threads you won't beable to read them . The color of the first threads and how high the color goes up the plug will indicate how hot the bike is running . A gentleman by the name of Kevin Baxter has a very informative video on reading plugs .

[Ironheadmike]

I check the main by timing how long it takes to go from point A to point B . The best time is the right jet . Your main is on from 3/4 to wot . Like I said if you pull the plugs when hot you will damage the threads eventually .

[Scotty]

You boys are all living in the past. You can't even read plugs correctly with the way fuel is now.
Come into the 21st century with the rest of us and run a O2 sensor and really get to know what your bike is doing.
Talk about doing things half assed.................

[kd]

   I was waiting for someone to bring it up.  You sure can't read a plug like you used to with todays unleaded corn fed fuel.  That's a fact.  Use the tools available and you'll know what you have to a decimal point and not be guessing.  Chopping the throttle, pulling in the clutch, rolling to the shoulder, engine temp, barometric pressure and humidity are demons that can't hide from an AFR gauge reading.  Besides, even if you could get a decent reading with modern fuel like "the old days", it takes a while for a plug to imprint properly and then you need to know what load and rpm range etc., etc., that you were in. 

[Ironheadmike]

You boys are all living in the past. You can't even read plugs correctly with the way fuel is now.
Come into the 21st century with the rest of us and run a O2 sensor and really get to know what your bike is doing.
Talk about doing things half assed.................

That's all good for rich/lean but can you little o2 reader tell if your timing is off or bad rings or valves ? A plug can. Even with today's gas you can still read a plug if you know what you are doing and know what to look for .

[Scotty]

You boys are all living in the past. You can't even read plugs correctly with the way fuel is now.
Come into the 21st century with the rest of us and run a O2 sensor and really get to know what your bike is doing.
Talk about doing things half assed.................

That's all good for rich/lean but can you little o2 reader tell if your timing is off or bad rings or valves ? A plug can. Even with today's gas you can still read a plug if you know what you are doing and know what to look for .

No it only measure AFR which is one big part of the equation.
Experience will get a person the rest of the way but anyone claiming they can read the AFR on a plug with todays unleaded fuel is living in a fantasy world.

[JW113]

This thread is digressing into two different topics.

Yes, one can get some diagnostic information from taking a look at the plugs. No question about it, I do it all the time. You can get information about the state of the engine. But, that is only part of it, you need to do a lot more than read plugs. And to tune the carb/EFI, forget about it. It might get you "somewhere in the ball park", but very unlikely ever a home run. I'm tuning my Shovelhead right now. The plugs look great. However, the AFR was WAY off.

The other topic is tuning the fuel delivery. All it took was once for me to try it myself with an AFR gauge, and there is no going back. The only way that I believe you could tune a carb/EFI as (maybe) accurately as an AFR gauge is either on a dyno and tune for max HP at WFO, or on a drag strip for best ET. And that is ONLY for WFO. What the AFR is at idle and cruise and part throttle, you will have no idea.

Resistance is futile. Why fight it?

-JW

[Ironheadmike]

I wonder how people got by before electronics told them what to do . Just like cell phones . IMHO they made people dumber and lazier. All these electronics telling people what to do, what would they do without them .

[Hossamania]

They would rebuild their motors every 20 or 30 thousand miles due to improper tuning.

[Scotty]

I wonder how people got by before electronics told them what to do . Just like cell phones . IMHO they made people dumber and lazier. All these electronics telling people what to do, what would they do without them .

Keep living in the past and trying to insult people by calling them dumber and lazier.
Sounds a lot like you are jealous of people who can & have embraced technology.
Still room for everything we learned from when we ran leaded fuel and had points instead of electronics but the world has changed and some of us went along for the ride and were not afraid of change.

[JW113]

I wonder how people got by before electronics told them what to do . Just like cell phones . IMHO they made people dumber and lazier. All these electronics telling people what to do, what would they do without them .

Au contraire, Mr. Ironhead Mike. I disagree completely. Let's take your example, cell phones, which is really a "smart phone". In order to use one, you need to know a heck of a lot more to use one than how to use an old rotary dial or push button phone from 40 years ago, when we were young. You need to educate yourself, else all the power of that smart phone is useless. The same is true of modern tuning equipment, like a dynamometer. You think any moron can just strap his bike to a dyno, and use it? No. The same is true with an AFR meter. You need to learn how to use it, and in the process, you gain knowledge. In fact, the first thing you learn is that what ever you thought you know about tuning without one, throw it in the trash. No comparison.

So... let me ask this. You want to take the Pepsi challenge, and try to out-tune an AFR? The irony of this question is, you would never know how well you did without an AFR to check your results.

Dude... this argument is not worth having. Like claiming you can time a motor better "by ear" than with a timing light.

No disrespect. Just trying to share the love. We live in 2022, not 1965. And we're all smarter now than then.
 

-JW

p.s. by the way, I am very concerned at how our society had turned into a world of "palm zombies", of which I proudly refuse to participate in.

[Ironheadmike]

I got 60000, 110000, and 55000, on my bikes . All stage 3 I just swap out lifters every 25-30000 miles. I also get 48-50 mpg . So that shoots your 20000 build theory out of the water . I'm not trying to insult anybody, I forget people are sensitive these days. Just stating 40 years experience . Besides the 20000 rebuild mark was due to poor oil circulation in the shovels and pans