MC-54-250 Overheating

[damorg5623]

I'm sorry if I am doing this wrong, I don't go to many, if any forums, so I couldn't figure out how to ask a question regarding this overheating problem, nor could I figure out how to post a comment.
Anyway, I have a 2011 MC-54 250cc. Scooter. I got it almost a year ago. It has just over 2,000 miles on it. I was afraid to change the coolant/anti-freeze, because of what I had heard about burping the cooling system. I checked the freeze level and it was at -45 so I left it alone. I did however, replace ALL of the other fluids as suggested.
I rode thru the entire Fall, Winter, and most of this Spring without any problems at all.
3 weeks ago my Scooter overheated at a red light. To make a long story short, I found that the insullation to the top connector that goes to the temperature sensing switch, which screws in to the bottom of my radiator, had been melted by one of the radiator hoses which runs across it and had been resting on top of it. This allowed the connector to get hot, melting the insulation, and the sensing switch got shorted out by the metal springy thing which runs the entire length of the radiator hose, which in turn kept the cooling fan from turning on. I was able to repair this with little trouble, and everything was fine for the last 3 weeks.
This morning, after riding approx. 10 miles or so, I was headed toward home when I noticed the temp. gauge had jumped up to the HOT mark again. This went back down to about half way whenever I throttled up and drove. But when I stopped at a red light for example, it would jump back up to HOT again. Then when I took off, it would go back to about half way again. It never did go back to normal until I got home and turned off the scooter. I'm guessing that my Thermostat is getting stuck?
I really have NO idea.
Could someone PLEASE HELP me with any advice that you may have. I have already read the other posts on this subject, and I am going to remove the original coolant, and flush the system tomorrow morning. I'm not sure where the thermostat is loctaed or how hard it is to get to it.
If someone could PLEASE tell me where it is, and how to get to it, that would be a Really BIG help.
Oh, also... I should be able to ride without a thermostat installed right?
Thanks Very Much !

[4getful2]

Normally, if a thermostat is stuck closed or not opening all the way, they will run hot while moving and be able to cool itself down at idle.
Are you sure the fan is functioning properly and the system is full of coolant?
On some machines ,you'll have to find the radiator cap and fill from there.

[damorg5623]

At this point I have NO idea.
I was able to flush the system TWICE with 5 gallons of water each time. Once I got the darn thing to burp, circulation would start, and then once the fluid in the radiator got hot, the fan would come on and everything seemed ok.
I went ahead and filled the system with coolant, it burped several times, but not before red lining HOT. It seems like once you get ALL of the air out of the lines, the coolant will start to circulate, and when it reaches the radiator, the fan will come on.
That is what happened yesterday.
Thinking that everything was going to be ok, this morning, I started the Scooter and let it idle for about 30 minutes. It NEVER got HOT, and the fan was running.
I decided that I needed to take a ride to fully test things, and to be sure that everything was good. I rode to the local Home Depot, about 3 miles. The temp. guage never went past normal. On the way back home I decided to take it out on the interstate. I got up to around 70 mph. according to my speedometer, and then I exited the highway. The temp. guage NEVER went past normal. I rode for another mile or so, when all of a sudden I noticed that the temp. guage was red lined HOT. I pulled over and turned off the scooter. I noticed then that the fan WAS NOT running. It cooled off rather quickly and I made it home. Home was just a few blocks away.
I had put in a call to Roketa on Friday of last week, when this all began. I was told that someone would get back to me. I just now got off of the telephone with a guy named Travis, from Goldenvale.
He said that it sounds to him like there is still some air in the lines. He also said that if I were to twist the 2 wires that go to the radiators temp switch, it should cause the fan to run all of the time. He also told me, because one of the questions that I had was... What makes the water pump turn? He said that the wate pump is connected somehow, I can't remember, to the drive shaft. It will always turn, and hardly ever goes up. He said that the way a water pump usually goes up is that the seal starts to leak.
So, I guess that my problem isn't the water pump.
So, it must be that there is still AIR in the lines that I have got to BURP OUT!
What do you think?
ANYBODY...

[spandi]

Did you replace the temperature sensor?

[damorg5623]

Originally Posted by spandi

Did you replace the temperature sensor?

No, I did not replace the temperature sensor.
First of all the temp. guage on my dash is working fine. This tells me that the temp. sensor at the thermostat housing is working properly. Is my logic correct?
Secondly, the Fan DOES come on, when I can get the HOT coolant to flow back to the radiator.
As things are, the temp. sensor at the bottom of the radiator thinks that the coolant is cold, because NOTHING is circulating. Therefore it doesn't turn on the fan. I have removed the thermostat thinking that with it out of the picture everything will flow freely... NOT !
I can only suspect that I still have some air in the lines somewhere.
I thought that everything was OK after I did the flush and fill.
It burped several times all over the place, the fan came on and the temp guage on the dash read normal. I let it idel for about 30 minutes and the temp. guage read normal.
However, I went for a ride on the Interstate, reaching about 70 mph. for about 2 miles. I exited and rode another mile. I had just thanked GOD for helping me to fix my overheating problem. Then when I stopped at a red light that's when I noticed that the temp. guage on the dash was reading HOT !
Now the fan was NOT running, so I headed back home.
Luckily I was only a few blocks from home, and I made it with no trouble.
I am going to try and burp this thing some more, as soon as the rain here in Baltimore stops. Hopefully tomorrow, or the next day.
Thanks for your response.

[damorg5623]

I found that you have got to have a thermostat in the system or it WILL overheat. Go figure. It seems that without a thermostat, the coolant travels too quickly thru the system and doesn't stay in the radiator long enough to get cooled back down.
So I installed my NEW thermostat and I am trying once again to "BURP" out ALL of the air using JR's tried and true method, which is listed in the TECH TIPS section.

[prodigit]

My 2ct would be, if the engine overheats, your coolant product will boil and evaporate.
Check your coolant levels.
Don't worry about burping, there's no such thing ( just fill it up and let it run).
you can easily add coolant, no need to replace the existing
just make sure you don't have no leak, by checking again after 100-500 miles, if the level has dropped or not.

I did that with my BMS.
I looked at the coolant color (orange), and bought similar color coolant.
The color doesn't really matter, but still I thought it was better than mixing blue and orange; just visually. The bike was orange so...
But really, stay away from Peak coolant! Cheapest and worst stuff out there.

And just refill. You can not overfill, even if you wanted to, the system has an overfill protection, and whatever too much you add, will just be pushed out of the system again.

[4getful2]

The water pump is normally driven off of the crankshaft,directly or via shaft thru the oil pump.
If you're having trouble burping or purging the air out of the cooling system, you may want to try putting the front wheel on set of car ramps or a couple steps up, this way the radiator is higher than the engine.As the engine gets up to operating range, rev the engine 3000-4000 rpms, in short bursts. you should have a lil catch pan underneath the radiator, so you can catch what spews out while reving .Best to leave the cap off while doing this and keep a close eye on the radiator level ,as it my drop suddenly, and have some coolant to add at the ready too.Usually if the fan has cucled 3-4 times ,you're good to go. At this time install cap and fill resevoir to proper level.
When the fan is running ,does the air it's pulling thru the radiator feel hot and the fan feels like its pulling good flow? If you have a garden hose(no high pressure), it might be a good idea to clean the radiator fins, both outside and inside, sometimes they do get full of road grime, dirt, bugs.