Heat creep

[MrJumps]

I am a believes that a engine will steady out with heat. If you where able to build a race motor that you could wot for a hour temps should keep creeping.

Greetings:

I must agree with Mr. Jumps. If the temperature doesn't steady out there's something wrong. If I see a slow climb I search for air leaks with carb cleaner or an unlit propane torch. If none are apparent, upjet the main however much is needed to achieve stability. Sometimes an air leak only happens with a hot engine; look for telltale base and head gasket seepage.

Now I have also been told a while back and for the life or me I cannot find it. But it whent a little like this. 'The temp will creep as long as your on the throttle because a bigger bore makes more heat and is only the same size ouside as a 50cc bore.'

Now if commen sense is hitting me square and staright than I belive that a 50cc bore and 72cc bore will have totaly difrent sizes and fin surface.

I am wanting input from quite a few members to see what they say. I am about to start tuneing along with others. The main question is "if you were to wot for 30 plus minutes would temps creep if the engine is build correct or will they even out?"

Thank you guys!

[noiseguy]

Heat creep just means you're producing more heat than engine can reject. Easiest way to make this happen is to run too thin on main jet and rocket around places.

Good point on smaller fins for a 70cc vs 50cc... but experience with members here is that the Elite's cooling system can handle the load in either case... lots of ppl have scoots that don't have this issue.

[MrJumps]

Im refering to wot for a while, the engine should even out after a while, if it dosnt then you would have an airleak. This is how I understand it.

[Meloshameless]

My purple elite can go all day wot and stay between 280-340. My other elite will hit 350 after 5-10 mins of wot and even climb to 380 on a long hill climb, which is when i pull over and let it cool down. I remedied a crank seal leak and the problem Persists, however it has a 23mm carb and a arrow pipe, where my purple bike has a 21mm and yasuni. These are the only differences. Im leaning towards the carb being larger but i dunno. Gonna put an air scoop and hopefully that remedies it. Oh also the hotter running bike's plugs always tell me its rich....

[patthesoundguy]

Should be able to run WOT and it should even out, creeping means it lean or not getting enough airflow or both. The fan should keep it cool enough as long as all of the shrouds are in place. My Dio af18 with the arrow copy pipe and big carb maxed out at 325F

['O'VerSe]

Higher rpms higher heat. Air cooled engine. Fan, cover, shroud, and outside air can only do so much.

[GuavaJam]

Wait, so u guys r saying if our 72cc bikes r tuned right, it should b able to go WOT on flat ground for longer than 5-10 minutes, with the temps reaching a point where it no longer increases? Presumably under 400F? Wow, my bike never did that

[MrJumps]

Wait, so u guys r saying if our 72cc bikes r tuned right, it should b able to go WOT on flat ground for longer than 5-10 minutes, with the temps reaching a point where it no longer increases? Presumably under 400F? Wow, my bike never did that

Yes, the way I see it is that, if you own a 2 stroke weed eater, power washer, etc you run that machine for your buisness for 8 hours straight wot most of the time. I have heard of Hawaiians running the whole large island at wot, ive been told by pretty much every vespa owner that you can sit in a high gear at wot for ever. Ive sat on wot on my car for a half hour one time. It just dosnt make sense why you cant wot for extended times if your bike is good.

[patthesoundguy]

Wait, so u guys r saying if our 72cc bikes r tuned right, it should b able to go WOT on flat ground for longer than 5-10 minutes, with the temps reaching a point where it no longer increases? Presumably under 400F? Wow, my bike never did that

Yup if my malossi mhr aluminium cylinder ran up to 400f it would mean certain death I'm sure especially where the aluminum reacts and spikes so quickly

[1man8scoots]

Higher rpm does not equal higher heat. Tuning is crucial.
It should be able to wot for as long as you want to. If not check for air leaks or upjet. If plug is wet you have an airleak.

[GuavaJam]

What are the most common places of air leaks? Found one on my mani, but bike still running hot.

[MrJumps]

Your case, intake, carb boot, ead, sparkplug hole, base gasket. Anywhere that can be split apart can leak.