Spark plug color, how long.

[Carter Powell]

On a new set of plugs at a constant speed how long on average does it take to get a good insulator coloring.

Thanks, Carter Powell

[KIRCHNER]

just an educated guess, 1 hr.

[LakeFever]

A short warm up and one hard pass. If your fuel is lean, it won’t last an hour. Find the leanest looking hole by examining all plugs while on the rich side of things. Then only use that hole with a new plug each time your trying to read. If there’s any white? Trouble. If it looks like new? Razor thin. Wet or color? Probably still rich. It’s really use your judgement and check more often than less. Easy as she goes. But to read the things you need to get it spooled up wot and shut it down if you can. Keep an eye on piston wash too. Half clean is about good imo.

Curious to hear what others have to say. This is the first time I’m doing this with a 2.5 just done a bunch of sleds. Used to jet down til the electrode was white just around the edges. Too close. Went fast. Blew up lots. I’m not going anywhere near that with these motors. Plus they seem to run great even rich as heck

[KIRCHNER]

plugs color from the bottom up. you need to look down inside the shell. they make a scope for that. dark brown fading up to med,brown should be spot on.

[LakeFever]

Another thought I had about plugs is wetness. Dry plugs with no wet at all in a two stroke means your in the zone. Tread lightly at that point.

[LakeFever]

Just did some tuning work that yielded huge gains. Over 5mph. I was shutting down at wide open. A little hairy and I got soaked but it is nec to see what’s what.

this was super fast, but too lean




this one is spot on and it ran excellent. I ran it wide open for over an hour with this setting. I will probably fatten it up just a hair more when I’m done trying to get my numbers up. Just for safety because right now I have really good fuel, perfectly fresh motor, and aces. Can’t always guarantee this fuel quality so better safe than sorry. Anyways this plug is good to go but consider this a limit. Go no leaner imo



one more note I had a very fat oil mixture on this run. 32:1 I tend to overdo oil at first and slowly roll back over time. More is better than less

[LakeFever]

Just did some tuning work that yielded huge gains. Over 5mph. I was shutting down at wide open. A little hairy and I got soaked but it is nec to see what’s what.

this was super fast, but too lean




this one is spot on and it ran excellent. I ran it wide open for over an hour with this setting. I will probably fatten it up just a hair more when I’m done trying to get my numbers up. Just for safety because right now I have really good fuel, perfectly fresh motor, and aces. Can’t always guarantee this fuel quality so better safe than sorry. Anyways this plug is good to go

[rjdubiel]

I ran it wide open for over an hour with this setting.

hopefully not continuous for a hour! haha. Looks good!! Cool you got that much gain, shows how safe the merc boxes are to keep people from hurting their motors.

[LakeFever]

Here’s the rest of my plugs. That plug above is from cylinder #3 which is my leanest hole





#2

[LakeFever]

hopefully not continuous for a hour! haha. Looks good!! Cool you got that much gain, shows how safe the merc boxes are to keep people from hurting their motors.

I gave no mercy but you are correct it definitely wasn’t non stop there are turns and whatnot. But I was floored coming out of every corner for an hour and ran it up as fast as I could pinned until I had to slow down for another turn. It’s kind of cool that when your really really aired out you can kind of cruise there without a lot of throttle. It takes a ton of juice to get it aired right out then you can keep it there pretty easy. Anyways can’t wipe the grin off my face today. I’m over achieving with this motor and that’s uncommon in most builds. Loving this merc

[LakeFever]

One other comment that I forgot to mention is I tuned this the same way I tuned sleds. I leaned it out to see that little white ring around the electrode and where you have to really watch is you can’t have any white at all on the anode ( the hook part of the plug ) and if you look at the first plug my lean one there is a tiny bit of white on the anode. You also have to watch for any ash color on the metal parts of the spark plug. Clean metal surface is ok but if it looks sort of sand blasted finish? Too lean. Just a couple thoughts to add that might help.

[Merc 2.5]