Pictures of my spark plugs - Honda Shadow Forums : Shadow Motorcycle Forum

Open Door · 08-21-2010, 10:40 AM

Here's a couple of pics of my carbon fouled plugs I pulled from the bike I bought a week ago. The bike had right at 16k miles when I bought it and the guy that owned it for 4 years said he only used it for bar hopping, short runs. I don't think it had been opened up on the highway in a while...

The front right plug was dragging when I removed it (thought it was cross-threaded) but looking at the threads it looks like there's dried up oil on it or something. It was a little loose in the cylinder so I'm guessing I was loosing compression and the oil had gummed up the threads. I'm going to run some alcohol on a cotton swab around the cylinder threads to see if that will help the plug screw in/out smoothly, like the other 3.

The front left plug was pretty loose also, like maybe finger tight if even that. Looks like oil was working its way out on that side too.

I imagine the combustion chamber (piston heads) probably look the same as these plugs. I'm going to run some Sea Foam through it to hopefully clean it out.

Uploaded with ImageShack.us

gat803 · 08-21-2010, 11:44 AM

Carbon fouled?
Those plugs are a little dark, but they're not that bad. One set of plugs (left or right) will always be a little darker than the other just because of where they are located in the combustion chamber.

These plugs are typical of an engine that's not been run very hard. Drop in a new set and go on your merry way.

Open Door · 08-21-2010, 11:57 AM

Thanks gat803. I looked at this chart as a guide: http://www.ngksparkplugs.com/tech_su...qs/faqread.asp

New NGK's were installed when I pulled those. I'm just now getting around to taking pics of plugs to post up here before they get tossed.

**Phil** · 08-21-2010, 12:36 PM

I don't know if this actually works; but I was told that you have to run it hard every now and then to keep the carbon deposits down....

I'm a pretty tame rider most of the time, but every so often, I run it like a "Raped Ape" and it seems to work for me.
Last time I checked my plugs, they looked pretty good. Of course, that could just be that the jetting is right on and the "Raped Ape" part doesn't really have anything to do with it.

It's still fun to kick it in the ass every now and then, so I think I'll keep doing it; even if it doesn't keep the plugs clean. lol!
Phil

gat803 · 08-21-2010, 01:11 PM

Some thing to keep in mind when reading spark plugs.
There are three engine operating ranges that are metered by seperate parts of the carb. Low range (pilot circuit), mid-range (jet needle), and wide open throttle (main jet).

These circuits do overlap and each has an effect on another, but if your motor spends all of its time in one range then that's the one your spark plugs reflect.
Most people tune for WOT (wide open throttle) even though they spend little time there, and pretty much ignore the rest of the range.
While the main jet is important, the pilot and jet needle have more to do with every day drivability than the main jet ever will.

Also bear in mind that reading plugs is more of an art than a science, and it is very hard to read plugs from a picture on the interweb.

Open Door · 08-21-2010, 03:48 PM

@Phil: I've heard the same thing... I always thought it was an urban legend type thing but it does make a little sense. And you're right, it IS fun gettin' on the throttle every now and then!

@gat803: GREAT info! I've never jacked around with jetting, sync, etc so this is all so new to me. I just basically matched my plugs to the pictures and came to an amateur conclusion.

MMC369 · 08-24-2010, 09:31 PM

#1 ~ Hey Phil, what is "Raped Ape"?

#2 ~ Hey Gat, Why does my '86 VT500C have 2 plugs per per cylinder?
What is the advantage?

THX
A J

jehamlin · 08-25-2010, 10:20 PM

Quote:

#2 ~ Hey Gat, Why does my '86 VT500C have 2 plugs per per cylinder?

I think it burns any remaining fuel on the exhaust stroke making it more efficient, but that said I really have no idea.

tubes_rock · 08-26-2010, 07:14 AM

Quote:

Originally Posted by jehamlin

Quote:

#2 ~ Hey Gat, Why does my '86 VT500C have 2 plugs per per cylinder?

I think it burns any remaining fuel on the exhaust stroke making it more efficient, but that said I really have no idea.

Both plugs in each cylinder fire at the same time. It creates two flame fronts assuring a more complete burn. That's all. Ford was doing the same thing on their vehicles for a while.

--Justin

**Phil** · 09-01-2010, 06:38 PM

Quote:

Originally Posted by MMC369

#1 ~ Hey Phil, what is "Raped Ape"?

It's a term used by people who own muscle cars. The term is in reference to their car being able to go fast.......

Also, I thought I remember hearing about a rock band from Canada called "The Raped Apes."
Phil

08-21-2010, 10:40 AM	#1 (permalink)
Open Door Member Join Date: Aug 2010 Location: Houston, TX Posts: 78	Pictures of my spark plugs Here's a couple of pics of my carbon fouled plugs I pulled from the bike I bought a week ago. The bike had right at 16k miles when I bought it and the guy that owned it for 4 years said he only used it for bar hopping, short runs. I don't think it had been opened up on the highway in a while... The front right plug was dragging when I removed it (thought it was cross-threaded) but looking at the threads it looks like there's dried up oil on it or something. It was a little loose in the cylinder so I'm guessing I was loosing compression and the oil had gummed up the threads. I'm going to run some alcohol on a cotton swab around the cylinder threads to see if that will help the plug screw in/out smoothly, like the other 3. The front left plug was pretty loose also, like maybe finger tight if even that. Looks like oil was working its way out on that side too. I imagine the combustion chamber (piston heads) probably look the same as these plugs. I'm going to run some Sea Foam through it to hopefully clean it out. Uploaded with ImageShack.us Uploaded with ImageShack.us __________________ 1985 Ninja 600 (way back in late 80's) 1998 Suzuki Bandit 1200 (sold) 1996 Shadow ACE 1100 Search the forums with Google -replace "search term" with your own keyword(s)

08-21-2010, 11:44 AM	#2 (permalink)
gat803 Senior Member Join Date: May 2005 Location: Michigan Posts: 4,871	Carbon fouled? Those plugs are a little dark, but they're not that bad. One set of plugs (left or right) will always be a little darker than the other just because of where they are located in the combustion chamber. These plugs are typical of an engine that's not been run very hard. Drop in a new set and go on your merry way. __________________ Hey look, a covered bridge...

08-21-2010, 11:57 AM	#3 (permalink)
Open Door Member Join Date: Aug 2010 Location: Houston, TX Posts: 78	Thanks gat803. I looked at this chart as a guide: http://www.ngksparkplugs.com/tech_su...qs/faqread.asp New NGK's were installed when I pulled those. I'm just now getting around to taking pics of plugs to post up here before they get tossed. __________________ 1985 Ninja 600 (way back in late 80's) 1998 Suzuki Bandit 1200 (sold) 1996 Shadow ACE 1100 Search the forums with Google -replace "search term" with your own keyword(s)

08-21-2010, 12:36 PM	#4 (permalink)
Phil Super Moderator Join Date: Jan 2004 Location: Sterling Heights, Michigan Posts: 6,757	I don't know if this actually works; but I was told that you have to run it hard every now and then to keep the carbon deposits down.... I'm a pretty tame rider most of the time, but every so often, I run it like a "Raped Ape" and it seems to work for me. Last time I checked my plugs, they looked pretty good. Of course, that could just be that the jetting is right on and the "Raped Ape" part doesn't really have anything to do with it. It's still fun to kick it in the ass every now and then, so I think I'll keep doing it; even if it doesn't keep the plugs clean. lol! Phil __________________ 1973 Yamaha RD-350 Sterling Heights, Michigan

08-21-2010, 01:11 PM	#5 (permalink)
gat803 Senior Member Join Date: May 2005 Location: Michigan Posts: 4,871	Some thing to keep in mind when reading spark plugs. There are three engine operating ranges that are metered by seperate parts of the carb. Low range (pilot circuit), mid-range (jet needle), and wide open throttle (main jet). These circuits do overlap and each has an effect on another, but if your motor spends all of its time in one range then that's the one your spark plugs reflect. Most people tune for WOT (wide open throttle) even though they spend little time there, and pretty much ignore the rest of the range. While the main jet is important, the pilot and jet needle have more to do with every day drivability than the main jet ever will. Also bear in mind that reading plugs is more of an art than a science, and it is very hard to read plugs from a picture on the interweb. __________________ Hey look, a covered bridge...

08-21-2010, 03:48 PM	#6 (permalink)
Open Door Member Join Date: Aug 2010 Location: Houston, TX Posts: 78	@Phil: I've heard the same thing... I always thought it was an urban legend type thing but it does make a little sense. And you're right, it IS fun gettin' on the throttle every now and then! @gat803: GREAT info! I've never jacked around with jetting, sync, etc so this is all so new to me. I just basically matched my plugs to the pictures and came to an amateur conclusion. __________________ 1985 Ninja 600 (way back in late 80's) 1998 Suzuki Bandit 1200 (sold) 1996 Shadow ACE 1100 Search the forums with Google -replace "search term" with your own keyword(s)

08-24-2010, 09:31 PM	#7 (permalink)
MMC369 Member Join Date: Jan 2010 Posts: 50	2 plugs per #1 ~ Hey Phil, what is "Raped Ape"? #2 ~ Hey Gat, Why does my '86 VT500C have 2 plugs per per cylinder? What is the advantage? THX A J __________________ Wish Indianapolis were in the tropics.

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