| Author | Message | ||
     Brinnutz |
Also posted in KV, but I'm wondering...I changed the intake seals a couple of weeks ago, and this solved my white plugs, and took away a pinging in the motor. Now, the pinging is back, and the plugs aren't black anymore. So, I'm guessing another leak?     | ||
| Sloppy |
To perform "plug reading" you need to perform a WOT test and shut down the engine with no idle. Also, the plugs are supposed to be new. Unless you've done this, plug reading is useless unless you have a major problem. Pinging is fairly common, especially in hot weather. I use a colder than recommended plug (NGK 9) 'cause I ride in 110F and it doesn't get much below 40F where I live. No more pinging and no fouling either. By the way, the center electrode looks a bit rounded (lost it's edge) -- you may want to replace them regardless. | ||
| Oldog |
my o2 YES! Grey, Yellow, Brown white with metal or distortion of electodes NO. | ||
| Beachbuell |
White is lean. Black is rich. Brown is good. Green or yellow is bad gas. | ||
| Georgedombeck |
I have never heard of anyone doing a "plug chop" on a 4 stroke. I would think you want to read the plugs from a normal riding situation, not wide open. | ||
| Crazyhorse |
What!!  are you saying wide open is not normal? | ||
| Oldog |
I have read about the testing procedure that Sloppy refers to, it is used to setup the main jet. | ||
| Stevem123 |
Being a mechanic for longer than I like to admit; Those plugs don't look bad at all for an air-cooled engine. Air-cooled engines run hotter combustion chamber temps so the plugs generally look a little more white than on a water cooled engine. But what do I know, I've only been wrenching since 1975...... BC Steve | ||
| Stevem123 |
More on those plugs: The first pic is bleached out by the camera flash. The second pic is showing a good profile without being washed out by the camera flash. The thing to look at primarily is the ceramic isolator around the center electrode. I see just a little brownish deposit and that looks about right for air-cooled motor. Hope that helps. BC Steve | ||
| Brinnutz |
Steve, Thanks for noticing. I forgot to mention the flash..It doesn't look that white in real life, in fact it does have a slightly brownish tint to it. Now, about the pinging. Do I need to run a slightly colder plug then? Any recommendations? | ||
| Buellistic |
Brinnutz: Since no one has asked, what is the plug gap on your your plugs ... You saw my 97S3T at the 25th ... Gap my plugs at 0.030 and running a 12 to 1 fuel/air ratio with high test gas ... Make sure yo do not have any intake air leaks ... | ||
| Brinnutz |
Buellistic, I sure did see her! Great meeting you! Also, I gotta pick up a plug gap-o-meter thingymajigger. I'm trying to figure out if it's running lean, because that would denote an intake leak. But, can the carb pop blow an intake seal? | ||
| Djkaplan |
The color of the insulator at the tip isn't where you 'read' plugs; you need to look closer at the base of the insulator. Back in the carb days before FI and sensors to read mixture ratios, tuners always carried a jeweler's loupe so they could illuminate and magnifiy deep inside at the base of the insulator. If you want to argue... read this first. http://www.strappe.com/plugs.html Gordon Jennings was a one of my favorite tech mavens... on equal footing with Kevin Cameron, both technically and artistically. | ||
| Brinnutz |
I wasn't reading the isolator..the metal prong piece is what I was inquiring about... | ||
| Sloppy |
I guess the point we're making is there are far better ways of determining if you have an intake leak. WD40 at the manifold is a standard that will tell you instantly. Plug reading has a place, but not in this application. Plugs are so cheap, maybe 3 bucks, that it makes little sense to NOT experiment going cooler. | ||
| Djkaplan |
"I wasn't reading the isolator..the metal prong piece is what I was inquiring about..." That's not where you read plugs. I think the article I posted a link to will explain everything you need to know about how (and where) to read a plug properly. It's not an article written by an internet bozo. Gordon Jennings was a highly respected tuner and writer whose articles on tuning are still valid. | ||
| Brinnutz |
I sprayed Brake Clean on it, to see if it would increase idle...Not much change, as it was a cold start and idle was increasing anyways. I'll test again tomorrow (Paper to write tonight). | ||
| Buellistic |
When did un-leaded gas become the forced choice at the gas pumps ??? Can say one good think about un-leaded gas, it will not foul a two stroke spark plug !!! | ||
| Kalali |
"...WD40 at the manifold is a standard that will tell you instantly..." But itn't that a bit messy? Why not use something like propane or brake/carb cleaner which will evaporate rather quickly with no residue? Just wondering. | ||
| Sloppy |
WD-40 does a great job of getting that black anodizing really shiny! That and most people already have it in their garage or can quickly recognize it at their hardware store... and don't get me started on "local hardware store" stories either.  | ||
| Buellsrule |
The plug itself should never, never be white. There needs to be an off white to reveal proper combustion. That bike is clearly running lean. Be careful with it and have it tuned and dynoed asap. |
