Rate my plug

[Freddy Snottgrass]

So I snapped my chain the other day and now I have a new one and I'm replacing it and part of replacing it is pulling my spark plug so I can turn the engine. I don't really check my spark plug is often as I should so this is really the first time I've seen it in a month or two. Is this running lean do you think. it seems to run perfect and if I go wide open it'll four stroke. I'm running a dellorto clone with a 65 jet at 3850 feet on a stock engine.

 

[BIG BOBBY]

the four-stroking IS because youre running rich,..95% of the time. so without even looking at your plug,...you're running rich.

drop your needle lower,...and/or lower your float height,....and/or unrestrict your exhaust/intake.

I did all those things and im still 4 stroking all over the throttle range till wide open,....and then it screams (powerfully) up to 6-6500,....and then starts sputtering like she has more to give but cant breathe. 4-stroking. I now have to resort to re-jetting. (down-jetting) and she is still running like a fat b*tch with a 66 jet!! (down from the stock 70)

---im prepared to,..and am going to,...go as low as a 60 if necessary.

 

[Freddy Snottgrass]

Yeah I just wanted an opinion on my plug color.

 

[MotorBicycleRacing]

Yeah I just wanted an opinion on my plug color.

Your pic does not show the porcelain around the electrode so how is that gonna work?
Google plug chop which would be starting with a new plug.

 

[LewieBike]

Note that Bobby's engine is the newer, unified head and barrel and they're ported a bit differently.

I'll assume it breathes a little better than the older two piece topend and consequently needs a leaner overall mixture. So don't go too far in changing jetting because of Bobby's experience. Just one step at a time and double check your float height each time.

 

[Freddy Snottgrass]

Your pic does not show the porcelain around the electrode so how is that gonna work?
Google plug chop which would be starting with a new plug.

You need to look at the porcelain? I thought you look at the electrodes.

 

[MotorBicycleRacing]

You need to look at the porcelain? I thought you look at the electrodes.

Did you Google plug chop?

 

[Freddy Snottgrass]

Oh then perfect. Im not trying to troubleshoot anything.

 

[darwin]

Zak what gap is your plug set at? In the above pic it looks huge, can't even see the bottom electrode at all. You might need a new plug or it's an illusion just from the pic. Gap should be .028 +/- .002.