Question: Two Stroke Operating Temperature | Spark Plugs

[yuckfoo]

I bought a laser thermometer. My engine seems to run at 260 F on short intervals (10 mins or so) and at 290 F at longer intervals (20 to 30 mins.) I read a comment from somewhere on this site and he said that he tunes his engines to run at 170 C (338 F.) Should I consider running a hotter spark plug? I am currently using NGK: BR6HS

 

[yuckfoo]

Here is a link suggesting that hotter temps are normal and stating that "The hottest a two stroke cylinder head should get is 450 degrees continuous running, 500 for short periods."

safest maximum cylinder head temperature

 

[Chainlube]

I bought a laser thermometer. My engine seems to run at 260 F on short intervals (10 mins or so) and at 290 F at longer intervals (20 to 30 mins.) I read a comment from somewhere on this site and he said that he tunes his engines to run at 170 C (338 F.) Should I consider running a hotter spark plug? I am currently using NGK: BR6HS

290-330 is fine. You probably won't go over that even on a hot day.

 

[DAMIEN1307]

290-330 is fine. You probably won't go over that even on a hot day.

I never seen it get over 285F under desert heat conditions myself, but i think that may well be because of the ceramic lined cylinder of the Zeda 80...DAMIEN

 

[Street Ryderz]

Here is a link suggesting that hotter temps are normal and stating that "The hottest a two stroke cylinder head should get is 450 degrees continuous running, 500 for short periods."

safest maximum cylinder head temperature

That's internally just as I said on FB, externally it well below that and 290f is getting hot, power loses can be noticed at that temp and ideally should be 250 or lower a bit higher with prolonged wot use but even then I don't like to see over 285f with a IR gun reading between the head and cylinder. Dragonfly/Jaguar quotes things and omits the proper context be careful!

 

[yuckfoo]

That's internally just as I said on FB, externally it well below that and 290f is getting hot, power loses can be noticed at that temp and ideally should be 250 or lower a bit higher with prolonged wot use but even then I don't like to see over 285f with a IR gun reading between the head and cylinder. Dragonfly/Jaguar quotes things and omits the proper context be careful!

I changed from the 72 jet to the 70 jet. It seems to be working fine, but on my last ride after awhile I did get a temp as high as 330 using the laser on the outside. Perhaps I'll go back to the 72 jet and change the needle clip if needed. But the thing is, there are several people telling me that 330 is nothing to worry about. That's the downside to this hobby. There is very little incontrovertible evidence as to what is good and what is bad. Everything seems to be opinions and there are very knowledgeable people who will say completely different things.

 

[yuckfoo]

I never seen it get over 285F under desert heat conditions myself, but i think that may well be because of the ceramic lined cylinder of the Zeda 80...DAMIEN

I changed from the 72 jet to the 70 jet. It seems to be working fine, but on my last ride after awhile I did get a temp as high as 330 using the laser on the outside. Perhaps I'll go back to the 72 jet and change the needle clip if needed. But the thing is, there are several people telling me that 330 is nothing to worry about. That's the downside to this hobby. There is very little incontrovertible evidence as to what is good and what is bad. Everything seems to be opinions and there are very knowledgeable people who will say completely different things.

I also tried raising the clip in the middle of that last ride from the center to one above center. It didn't take me long to realize that was not what it needed. It sounded slightly different and when coming to a stop the motor was idling faster than it was previously. I'm pretty confident that it was not getting the fuel it wanted. Perhaps before I try changing back to the 72 jet I'll try raising the needle one. (Clip to one below center.)

 

[DAMIEN1307]

I would first, move the clip to one below center position and then see if it runs better before rejetting back to the 72...one thing at a time to eliminate other possibilities...Then if its still not quite right, try the 72 again...Just my thoughts on how i would approach it...You live close to sea level...DAMIEN

 

[yuckfoo]

I would first, move the clip to one under center position and then see if it runs better before rejetting back to the 72...one thing at a time to eliminate other possibilities...Then if its still not quite right, try the 72 again...Just my thoughts on how i would approach it...You live close to sea level...DAMIEN

Yeah I always do one thing at a time so I know what did what. Makes it all take longer though. That and having to drag my bike down from the 3rd floor and back keeps me from trying stuff every day.

 

[yuckfoo]

That's internally just as I said on FB, externally it well below that and 290f is getting hot, power loses can be noticed at that temp and ideally should be 250 or lower a bit higher with prolonged wot use but even then I don't like to see over 285f with a IR gun reading between the head and cylinder. Dragonfly/Jaguar quotes things and omits the proper context be careful!

If it matters my readings are as close to the spark plug as I can get. That is where I had read to take the reading from. So my readings are probably identical to what one of those digital gauges that go on the plug would show.