Help reading plugs

[Capt Fin]

Ok y'all. I finished the install of C70TLRZ carbs on my 2009 50TLR. I made some runs at WOT. How do these plugs look?

plugs 1 and 2.

[Capt Fin]

and plug 3.

[Chaz]

Rusty

[warriorcookie]

http://www.nightrider.com/biketech/readplugs.htm

Teach a man to fish?
Reality: I'm no expert, so my comments aren't worth much.

[Merc 2.5]

u have to look at the ring at very very bottom of porcelain. Easiest is to cut the plug open and look. Thats where it matters tho and its kinda hard to see , if that's to much work read pistons. Get new set plugs need be lookin at burn on strap also but it n rough shape



Stole this pic from chaz

[Capt Fin]

u have to look at the ring at very very bottom of porcelain. Easiest is to cut the plug open and look. Thats where it matters tho and its kinda hard to see , if that's to much work read pistons. Get new set plugs need be lookin at burn on strap also but it n rough shape

Stole this pic from chaz

Thanks for the direction. I'm headed out today to pick up a set of plugs for a few WOT runs and to cut open.

[Chaz]

If you want an accurate representation of whats going on inside . It's best to warm the motor up on old plugs . Put the new ones in , run the motor up to wide open with the boat tied to the trailer and a test wheel on the motor . Let it run 10 seconds wide open and turn the key off .. pull the plugs and put them in a piece of cardboard (in order)
If you have a lighted magnifying lens .. as 2.5 sez .. the ring at the bottom is fuel load, the center electrode and the strap will show the plugs heat and OAL temp . Timing will effect how much heat gets into the strap. Don't let the mark make its way around the bend .. flirtin with disaster ..

[Capt Fin]

I was going to bring the new set of plugs with me out on the water, warm the motor up, install new plugs, do some WOT runs and kill the motor. Then I was going to bring the boat back in on the old plugs. I've done some reading since our last posts and your info seems spot on. I really appreciate it.

[Capt Fin]

Ok, update. Warmed the motor up on old plugs and installed new plugs. Ran the boat at WOT for about 4-5 minutes up the channel and cut the motor. Powered in on old plugs. Here's what the new plugs look like from top to bottom 1, 2, and 3.

[Capt Fin]

[CI STV]

Here’s a screenshot of a graphic plug reading chart I saved a while back from the Yellowbullet forums:

Bear in mind this is for a four-stroke, but I think the same principles apply as to heat range and jetting. A rich 2-stroke plug may be wet with oil as well, since unlike a 4-stroke the oil is in the fuel.
BTW: You need to be using a magnifying glass with good light to properly read plugs and it’s hard and sometimes misleading to read plugs from a photo someone takes, unless it’s magnified and has really good definition.

[Capt Fin]

I just cut more threads back from the first two plugs and revealed the true carbon ring. All three look like this...



With my 14p prop it falls on its face at 3800 rpm and I have to back it way off till it clears out then I can slowly run it up to rpm. With a 10p prop it doesn't fall on its face until WOT. Any ideas? Can I go one main jet size smaller from a 145 to a 140?

[Chaz]

When you cut the plugs on the thread side , you run the risk of wiping the ring off.
You can cut them from the top side and slide the porcelain out of the body.

The three plugs you had in your hand show a grey ring at the base. Once cut , not so much.
The discoloration of the ground strap looks to be just before the bend on the first two starting to go around the bend on the one to the right.
save the body too , look at it from the side , you can see how far the heat traveled.

An oldie .. but goodie ...

https://www.strappe.com/plugs.html

How to cut plugs ...