Spark Plug Color Reading Chart

Quickonstep · Toggle Post Display ( 0 ) [ ] [ #1 11-26-2004

I have seen this come up a few times in the past few days and havent seen anything about it tech wise on this site, so here is a little contribution to the site. Enjoy!

The First picture is of a normal plug, how it should look if it is jetted properly.

The second picture is your plug if your engine is running to rich. Jet down a a little to correct.

The third is a fouled plug. This happens becuase you have a crank case leak, blowby, dirty air filter, low compression, eccessive low rpm operation.

The forth is of your plug if your machine is running too lean. Jet up a little to fatten up the mixure, or make sure the timing is set right.. This is also a tattletale of overheating.

The last image is of a plug that has deposits on it.. not so much to worry about in a 4 stroke, but in a 2 stroke it happens due to bad oil, wrong mixture (premix) or dirt going past the air filter.

Hope yall can use this.

Yamahauler · 11-26-2004

wow, thats perfect, i was just gunna check my jetting, thanks!

Quickonstep · Toggle Post Display ( 0 ) [ ] [ #3 11-26-2004

maybe this should be sticky, and i cant remember where i got the pictures, someplace on the net a few years ago. Or even put on the main page.

Jesse

Yamahauler · 11-26-2004

i think they should put it on the main page. Good info.

Billy Golightly · Toggle Post Display ( 0 ) [ ] [ #5 11-26-2004

Yes thats definetly main page worthy. I'll put that on there next update. Should help out alot of other people.

Quickonstep · Toggle Post Display ( 0 ) [ ] [ #6 11-26-2004

honda if youd like me to i can make a doc or a html with it setup nice and neat.. if youd like...

Jesse

Billy Golightly · Toggle Post Display ( 0 ) [ ] [ #7 11-26-2004

Its not really necessary, but if you'd like to that would be fine. Just email it to me

Quickonstep · Toggle Post Display ( 0 ) [ ] [ #8 11-26-2004

ok.. i can leave it like that.. seems pretty understandable... hope it helps a few people. i posted it because i have seen a few people posting about rejetting and what not.

Jesse

googel35 · 11-28-2004

Them pictures really help alot because I know a lot of people have that problem and the spark plug is a good way to check it.

twgranger · 03-14-2005

Did this ever make it to being a sticky??

kando · 03-14-2005

yes its in the tech section.

HRC1 · 03-14-2005

this may help also. http://www.strappe.com/plugs.html