hotter or cooler plugs

[luckydevil]

I bought a hotter set of plugs. 4R instead of 4R5.
The guy at the dealership warned me about getting to hot.
He said be careful or i might burn a hole in my piston.
Really?
I did not think that was possible with a spark plug.
waja think?

[883 custom]

Why get a hotter plug? If it was running good with the other plugs I would not switch them. Not real sure about the hole in piston thing, guess it could happen. What you want is for the electrod on the plug to burn half and half, in other words the electrode will be black towards the threads and burn clean near the tip. Hope I didnt confuse you.

[luckydevil]

I bought em cause my bike was hard to start after a ride.
Let it sit for twenty and it won't wake up.
It just sits there and pops in the pipes or the carb
Every thing else seemed good.
Plugs have a bit a black on em. but no carbon smoke or bog.
The bendix pulls strong and smooth from idle up to 5000.

it's a 75 if that matters.

[883 custom]

Hmmm...if its popping in the pipes when trying to crank it is rich or "bleeding" past the seats. Try holding the throttle(not pumping) open abit and see if that helps. If the electrode is burning half and half that is the correct heat range for the engine.

[luckydevil]

The electrode is mostly black.
That means rich.
I live in broomfield colorado.
I have an ajustable main.

i don't want to lean it out too much i KNOW that burns pistons.

[IronMick]

I use a hotter plug in my rear cyl to burn off the carbon buildup. NGK6 in the front, NGK5 in the rear. With NGK the lower number is the hotter plug. This allows me to set the mixture rich enough that the front plug is gray to tan instead of white to gray [or just plain white!]. The rear plug is quite dark by comparison.

[dabronco]

If ya use too hot a plug, it can pre-ignite and that will BLOW a hole in a piston. Most bikes can take a few more cranks to start after a heat soak. The fuel wants to vaporize instead of atomize. Also the oil is thinner and doesn't seal the rings as well. Kick it thru with the throttle more open than normal a couple times. (Or crank it) Then close the throttle to your normal position. Some times all mine needs is a couple twists of the loud handle and hit the starter. Sometimes the fuel in the carb bowl evaporates some, (if you shut the gas off when you stop) and just turning the gas on a minute earlier while you get yer helmet on, works.

[luckydevil]

I do notice a little better burn on the front.
I will try mixing it up when i get it starting.

Does plug heat change head running temp at all?
Would going colder lower the operating temp?

I have tried all kinds of throttle positions.
twist + twist and hold works when cold.
The only one that worked hot is wide open, same as a flooded engine.
That only worked once.
The timing is good.

If the idle was too lean, and the main too rich?
Would it make it hard to start hot without flooding?

[dabronco]

They's all different man. It's hard to diagnose jetting with a starting problem.

[luckydevil]

Yeah.
I hoped not.
I'll just keep trying.
Change something: ride: wait: start
Change something else: ride: wait: start
Again
Again
At least i have an excuse to ride.