I totally agree, thats what im thinking as well with these hot spark plugs.

I said it runs better with the new right side crank seal because it was sucking oil from the crankcase into the combustion chamber and it was smoking like an angry dragon...

Before the crank seal replacement it would run for 1 hour and die with no spark , it smoked a lot too and didnt have all its power.

With the new right side crank seal, it now smokes normally (just a bit) and its got all its power (i think) Its able to lift its front wheel without me pulling on the handlebars in 2nd gear which is pretty good for such an old heavy beast i think. It also runs for 3 to 4 hours now with 1 spark plug but it still dies after that with no spark. Also, quite often, when it sits for a couple of days, when i try to start it, it starts for 1 second and dies with no spark. Then i have to replace the spark plug even if it looks perfectly good (to me) no spark at all and even if i touch the spark plug to my tongue and crank the bike, i dont feel any electricity. Sometimes it starts (cold), runs, i go 150 feet and it dies.
Pretty anoying since you cant ride the bike without a spare spark plug in the little hiden toolbox on the side of the bike.

Im gonna post pictures tomorow if ive got time

Good to be cautious about cooking a piston crown, but that's really not a concern with using a single stage hotter plug....unless you are on the ragged edge of lean AND OR running your DT extremely hard all the time. Warmer spark plugs by themselves won't cause engine damage, remember too that when Yamaha were testing their machines they use the coldest plug possible. Using a little warmer plug for trail riding or city duty won't hurt a thing

yeah, i ride my Enduro pretty hard since im not used to have such little power from a 250. The Dt has good torque but its nothing compared to my mighty Rm 1990.
Thats why i want to be cautious whit the engine.

Here is a pic of the true beast.

Does it have a resistor spark cap?You do not want to be running both,in fact I would not run one at all since your not listening to a radio as you ride whats the point?Also:From Air Heads BMW article www.airheads.org/technical-tips-articles...-plug-caps-and-wires

im going to take a picture of the spark plug cap as well tomorow
Im fairly convinced its the original one though.
Is the orignal cap a resistor one ?
Ive never heard of such things on the other 2 strokes ive worked on ?

Do you have any factual documentation on this claim? Like something from a spark plug manufacturer?

Never heard of this before....

In my opinion the claim is legit because it is common sence.
For instance if a customer brings you a 2 stroke motorcycle that runs, but it dies when its got a load on the engine, you might think its because a weak spark and perhaps a weak ignition system.
In this case if the spark plug looks good you might want to give it a smaller gap to see if it has an effect on the problem, but this would be a bad idea since the spark plug is used and the metal is not as flexible since the carbon reacts with the electrode and makes the metal stronger but it also makes it more brittle (science fact).

So in this case it would be better to replace the spark plug and give it the same gap as the old one and see if it changes something to the problem. Just start the bike and give her a rip. If its not better with the new spark plug, then you can give it a smaller gap because the spark plug didnt have a chance to build up carbon and to react with it.

Only in this case can you regap a spark plug that has been used. If it has been used more then a few minutes i wouldnt regap it. In any case, a spark plug is worth from 1 to 10 dolars and it is way cheaper than a cylinder head and a piston. You better prevent the problem than repair it. Because when an electrode breaks, the bike doesnt die since the spark jumps to the side of the spark plug and the engine can do loads of damage to itself before you kill the ignition.
Ive seen that happen several times.

I couldnt take pictures of the spark plugs today because my girlfriend's Bmw E24 635 CSI 1987 had a missfire on the injector *1 and it ran like a bag of **** and she wanted to take her out for a drive since winter is comming soon here in quebec canada. So i had to fix her car for her (she did help though).



She also owns a Bmw E34 M5 1989 but since im at work and i dont have my cellphone i only have this small picture, let me know if youd like to see a full size picture of this awesome car.



Tomorow i also have to replace the struts on her toyota daily driven car so i dont know if i will be able to take some pictures. Ill keep you updated.

The statement is from A BMW tech article,but I have personal knowledge of it happening,not on a 500$ scoot but a $250,000 Ferarri at the dealership!
www.airheads.org/technical-tips-articles...-plug-caps-and-wires
When the plug is fired the steel becomes tempered,look at an RC hardness chart for reference the tip becomes blue to black and its hardness becomes enough to cut glass.

It is a "science fact" that carbon steels can be hardened... more carbon generally = more brittle...

I know a little about hardening and case hardening steels and I just find it impossible that any reaction occurs between the combustion chamber "carbon" and the steel in the side electrode. The steel has to get to a very high temperature and then be quickly quenched for hardening to happen... if the side electrode reached the temperatures required you'd have a lot more problems than the metal possibly getting "brittle"... plus the "carbon" would have long burned off...

OK... I guess you read it on the Internet so it must be true! (just giving you a hard time)

Ummm... "tempering" reduces the hardness and brittleness of steel... and I haven't ever tried to cut glass with a spark plug... you should do a YouTube video showing that... I'd like to see it.

Can spark plug ground electrodes break off? Absolutely. I've heard it happening with something as simple as a loose spark plug creating a resonant vibration in the electrode... And a few years ago Bosch had some reported side electrode failures on their platinum plugs... And if you bend metal back and forth enough times it will eventually break.

But some kind of reaction of combustion chamber carbon and heat making the side electrode brittle? Sorry... not buying that explanation just yet. I'll take my chances and continue to re-gap used plugs like I have for many, many years.

Nice job derailing this thread but if I must respond,
Encyclopedia BritanicaHmm guess it means BOTH hardening and softening,weird.I guess if you find it impossible there could be no reaction with the carbon then I guess you've never heard of vapor deposition
But if you think the steel tip of a plug is not hardened after you are essentially running it in an arc furnace then blasting it with a charge of cool misty fuel is not quenching it,your full of it.Never mind thework hardening of expansion and contraction of the firing thousands of times.Keep regapping used plugs at your own peril.
P.S.
Carbon doesn't "burn off" look at your pistons crown!