HT Ideal running engine temperature?

Technocyclist · #1 02-09-2010, 01:28 AM

Ok... my aluminum head gasket melted into the cylinder... the engine still starts, runs for a few minutes and just dies... upon inspection, it was discovered about this issue... so did my engine run too hot? too lean? what should be the ideal running temperature of an HT engine? and what are the ways to know this temperature without using a thermometer? like a drop of water should not boil on the head, or if it does how long before it fully evaporates?

any comments are highly appreciated... Thanks...

stv1jzgte · #2 02-09-2010, 07:39 AM

Yes water will boil in the motor but ive never checked the opperating temp. At a guess between 100-150 degreese c possibly more!
The only way i could think you would melt a gasket is if you had the wrong heat range plug.
Im pretty brutal to my bike and it gets hot here, never had that happen.

Got a pic??

Pablo · #3 02-09-2010, 07:43 AM

Anyone have an infrared gun?

Or heat melt crayons?

But if your HG melted, you are running to hot. My guess is that you are running too lean on your air fuel mix.

Gareth · #4 02-09-2010, 08:32 AM

If your cylinder and head surfaces are not flat you run the risk of blowing a head gasket. Once the head seal is lost oxygen will enter creating a leaner condition causing that section of gasket to melt. Eventually the leak will become so great that compression is lost sufficiently to the point that the engine will no longer run, if seizure does not occur first.

This can be aggravated by the natural tendency of 2 strokes to lean out upon long wide open runs, and the natural tendency to run a little engine wide open.

**Norman** · #5 02-09-2010, 11:24 AM

I've done some reading with infrared heat gun these may not be the best reading but here is what I've seen.
at idle speed they run about 200 to 250 f.
The limit should be 450f this is just a good guess as I've read that an air cooled vw engine this is the higher limit for them. I've seen higher temps on my racing kart up to 500f(read off the cylinder temp probe under the spark plug) which is not supposed to be good for them and the 450f is what I've read is supposed to be the higher limit. I didn't know I'd reached that temp until back in the pits when I read the history off the tack/head temp gauge.
Under riding conditions they run around 350f best guess as it to hard to shoot it with the temp gun. I'll ride it stop, then shoot it right by the spark plug base. This gun has a laser pointer that shows where you are pointed when reading. It's probably not real accurate.
I installed the head temp and rpm gauge on the bike it had so much RF from the ignition the gauge didn't work properly. Plus I didn't try to correct it a quick try it would not read right and I didn't want to change all the set points in the gauge from the kart.
I was lazy.

professor · #6 02-09-2010, 02:24 PM

If you do use an infra red reader, the part you shoot needs to be flat black or the results will be off some.

**Dave31** · #7 02-09-2010, 05:43 PM

http://motorbicycling.com/f3/optimum...ing-13657.html

http://motorbicycling.com/f3/engine-temp-10471.html

Technocyclist · #8 03-03-2010, 04:36 AM

Quote:

Originally Posted by stv1jzgte

Got a pic??

Here's some pics. Did'nt had the time to dismantle and take pics till now...

As you can see the inner edges of the Aluminum gasket melted, which scratched the sidewalls of the barrel, and made some small holes on the piston head...

I think using a head gasket sealer is better than this Aluminum gasket...

stv1jzgte · #9 03-03-2010, 09:25 AM

Techno i think thats happened because the gasket can sometimes protrude into the cylinder and is exposed to combustion temps. Either shoddy manufacturing or from being squished alot if its old.

Venice Motor Bikes · #10 03-03-2010, 11:09 AM

Yeah... Just install a new gasket & recheck your mixture! Make sure the plug tip looks like a nice light brown color! ( & use the right # plug!)