HELP!!! 2013 Jonway YY250TT overheating By jburd (Read 939 times)

[jburd]

Hey everybody. I need some help here. I am working on my friends 2013 Jonway YY250TT. The bike has less than 1500 miles on it. This thing has been in the shop more than it has been out on the road and I'm at a loss. At 1000 miles we were doing the routine maintenance and decided to drain all of the Chinese cool aid out of cooling system and replace with good Preston 50/50 coolant. Everything has gone downhill from there. We followed the same burping process that I have done time and time again successfully on other bikes including my Linhai 250. The fan kicks on with this thing but it just will not cool the scooter. You think it is working fine and jump on it and go around the block and it overheats. At some point my friend was riding it and actually blew the head gasket. We have replaced that. We have replaced the thermostat. We have flushed it out multiple times and it doesn't help. I actually took the radiator and all the hoses out and flushed it out. There was no blockage that I could find in the radiator. No matter what we do, as soon as we get to higher RPMs the gage just shoots up to between 1/2 and 3/4 and will not come back down. Anybody have any ideas? Please help. I want this thing out of my garage and my friend wants to ride it. This has been going on for the last 2 months.

[jburd]

One question comes to mind I thought I would throw out there. When I took the radiator out, I found one of the fan mounts on the side of the radiator was snapped off. The welds that hold it to the radiator came off. In the process of fixing that, the wires to the fan also pulled out of the plug. I had to reconnect the wires. My question is which way should the fan be blowing. I thought there was a possibility that I reconnected it in reverse. The fan is actually pulling air from the outside in not blowing out. Not sure if that makes a difference or not. Thought I would throw it out there to see what everyone thought.

[gatekeeper]

The fan should cause cooler air to pass through the front of the radiator to the engine side. If the fan it mounted in front of the radiator it should push air through. If the fan is mounted behind the radiator it should pull air through.

Also, are you sure the water pump is moving the coolant through the system?

[ellpee]

Sept 17, 2014 22:54:34 GMT -6 gatekeeper said:

The fan should cause cooler air to pass through the front of the radiator to the engine side. If the fan it mounted in front of the radiator it should push air through. If the fan is mounted behind the radiator it should pull air through.

Also, are you sure the water pump is moving the coolant through the system?

That was my thought too. If the burping was done right, new thermostat, no blockages, a defective water pump would appear to be the last possibility. Of course the water passages in the engine itself could be blocked, but that would be unusual to say the least ....

[jburd]

We have replaced the water pump the thermostat and the head gasket. I have gone through the entire cooling system and there are no blockages that I can find. it doesn't make sense. The water pump is definitely pumping coolant. We are kind of wondering if maybe the gauge itself is bad. When my friend got the bike the speedometer was in km. He requested a new one with miles from the dealer. They sent us a used instrument panel with about 500 miles on it. We are kind of thinking there's a reason it was used with only 500 miles on it. The turn signal lights don't work on it and the fan light isn't there. My thought is could it be possible that it isn't overheating but the gauge is just running high. They might have sent us a defective panel. The problems started after we replaced the panel. What we are thinking is that we should use a laser thermometer to gauge the actual temp of the block to see if it is actually overheating. It gets up to around half. It used to be around a quarter. What do u guys think? Does anyone know the actual temp the engine should be running at?

[gatekeeper]

Don't quote me but I think the thermostat should begin to open around 167 degrees. You can use the pan of water on the stove test to see when it starts to open. I think the engine should run between 200 to 220 degrees. It is possible the gauge is off. While running at halfway on the gauge does the fan cycle on and off or does it run constantly? If it cycles on and off while the scooter is running then I would say what your gauge is reading is the "new" normal.

[ellpee]

My 2011 Roketa runs normally at about half, at which point the fan cycles on and off to keep it there, so I'm not sure you have a problem if it's only going up to half. (BTW: "fan light"? I don't have one of those on the Roketa, only the temp gauge.)