Hyosung MS3-250 overheating By wayneb (Read 2,818 times)

[wayneb]

I've had this Hyosung MS3-250 for 4 years now, have 9600 miles on it now. Never had a problem with it overheating before, although others have said that their temperature guage never goes over 2 bars, mine would always run at 2 bars out of town, but go to three bars in town. The guage goes to 5 bars total. For the last week it still runs at 2 bars out of town, but after riding in town for a while it will go to 5 bars and overheat. I like to ride this thing, but am not the most mechanically inclined person. I took the front cover off and cleaned out the radiator fins, started the scooter and kept an eye on the fan, it would come on and off like it is supposed to, never went over three bars. Then I took it for a ride around town for about half an hour, never went over three bars. Then took it for a ride out in the country and it went to 2 bars. Came back into town and it went to 5 bars and overheated again after about 10 minutes of riding in town. I can't hear if the fan is running while the scooter is running, but I shut it off and turned the key back on and the fan was running. It's been like this for the last week. What do I need to do to find out what is causing this. I thought about buying a new sensor or thermoswitch, but I don't want to go buying a bunch of parts and not knowing what it is, the parts aren't real cheap for this scooter. Love to ride but don't like to fix them. No hyosung dealers in my area.

[alleyoop]

Have you checked the level of the raditor antifreeze it may be low. Riding in the country or outside where you are crusiing at a good speed the air flow is enough to keep them cool. But slow them down and if everything is not working right they will overheat. It could be the sensor is not coming on quick enough and only kicks the fan on when the temp is already to high.

You could also connect a direct toggle switch to the fan when riding in town and if you see the temp going up you can turn on the fan with direct battery juice and see if that lowers the temp.

If it does then you know the fan is NOT KICKING on when at the right temperature.
Alleyoop

[wayneb]

The antifreeze is at the right level. I did a coolant flush yesterday and replaced the antifreeze, but it didn't help any, still overheats in town. I've replaced the antifreeze every year since I have had it. Not sure how to wire up the toggle switch, will have to do some googling on that. I thought it might be the sensor going bad since it just started in the last week, but if I could wire a toggle switch then I would at least know if the fan isn't coming on when it should.

[wayneb]

I can't hear if the fan is running when the scooter is running, but if I remove the cover over the radiator cap I can look in with a flashlight and see if it is running. I just did this with the scooter running in the garage. The fan used to kick on when the guage hit three bars, and then shut off when the guage went to 2 bars. But now it is kicking on when the guage gets to four bars, and shuts off when the guage goes back to three bars. Went through 5 cycles this way. So it is running one bar hotter than it used to.

[alleyoop]

I that case I would just replace the temp sensor. Also make sure the connections on it are good and not rusty or dirty. I am not an expert on this so you may want to wait for JR he is the expert on the cooling of these scoots.

I will email him and see if he has some time to chime in, he did say he did email me and said he would not be around for a couple of days.


OK I just emailed him and gave him the link to this post.
Alleyoop

[wayneb]

I've also noticed it takes longer to get a full charge on the battery, just noticed this about the same time the scooter started overheating in town. I always plug the scooter into a battery maintainer when I'm not riding it, and it usually just takes a couple of minutes for the light to go to a flashing green. Now the light stays on red for a long time before it goes to flashing green. I'm due for a new battery, but could this possibly in some way have anything to do with the problems I am having with the water temperature running hotter now?

[wayneb]

Jul 10, 2013 18:10:50 GMT -6 alleyoop said:

I that case I would just replace the temp sensor. Also make sure the connections on it are good and not rusty or dirty. I am not an expert on this so you may want to wait for JR he is the expert on the cooling of these scoots.

I will email him and see if he has some time to chime in, he did say he did email me and said he would not be around for a couple of days.


OK I just emailed him and gave him the link to this post.
Alleyoop

Thanks, Alleyoop. I do most of my riding out of town anyway so if it takes a little while to figure this out it is no problem. It runs just great out in the country. I've been doing some checking on parts on this scooter, and it pays to search around on the internet for a while. I've found a site that has parts for less than half of what most other sites want.

[alleyoop]

Yes, it pays to google parts prices are all over the place from different sellers. Some are real greedy and ask 2-3 times what someone else is selling the same part for. Usually what causes that is they most do not buy in volume the more you buy at one time the cheaper they can get them for. As an example for carbs if you buy 100 of them you pay like $11.00 dollars for one and then you pay anywhere up to almost $100.00 dollars for one. All this stuff is made in china so it all depends on the volume.

Yes the battery you have is going south on you and when starting the scoot it really draws a lot of juice if you have to keep cranking before it starts. As you know the charging system on these things are minimum at best so any extra requirements from the battery really empities the battery and then if your charging system is not the greatest that comes into play as well.

You can see how your charging system is operating, start the scoot and put a multi meter on the battery and see what the voltage reads, then rev it up to about 3000-4000 rpms and if you have a good charging system it should go up to 13+ Volts. If it does then your charging system is good but your battery is not holding the charge for very long and looses it sitting there.
Alleyoop

[cruiser]

Welcome to the forum, wayneb. It seems you are taking good care of your scoot.

Your scoot seems to be working fine at highway speeds when there is a lot of air flow through the radiator. So, good air flow equals normal cooling for your scoot. Around town driving is another situation because not much air is moving through the radiator. The fan does most of the work in this situation. If the fan is running when you say the scoot is overheating, then the sensor is doing its job. Sounds like the fan is not moving enough air. I would guess that it's getting a bit tired after four years. The bearings may be starting to dry out causing a drag on the fan speed. This may be aggravated when the fan has been operating a while and is getting hot. Some of us old timers even lube the cooling fan bearings as part of the PDI.

Since the fan is probably running longer trying to do its job, it is draining the battery more. This could explain why your charger is sensing a lower charge on the battery.

[wayneb]

Thanks, cruiser and alleyoop.
I went to the store and bought a new battery because I think I am due for a new one anyway. Will get it charged up overnight. This scooter was made in South Korea and came with a 9BS battery. However, they had to modify it for the United States so that the headlights would come on when you turn the key on. Others had said it caused them problems and put in a 12BS battery, so I put in a 12BS battery after I had bought it.

The fan could be wearing out, but it doesn't seem to run longer, just kicks on later and shuts off sooner. Kicks on at 4 bars now instead of 3 like it used to,
and shuts off at 3 bars now instead of 2 like it used to. The fan assembly will cost me $276 from Alpha Sports, or $104 from Moxie Scooters. A big difference in price between the 2 places. I just don't want to start spending money on parts and have it not be the right part that I need, because it seems like nothing is cheap on this thing. These things are great to have until parts start wearing out on them. The belt on this thing is over $100 every where I look, but Alpha Sports is out of this world asking $199 for it.

[wayneb]

I'm beginning to think it may just be a sensor going bad and sending bad information to the guage. The guage is showing one bar hotter than it used to all around for my different driving conditions. The scooter is running just great and is not losing any antifreeze, if it weren't for the guage reading hotter I wouldn't even think it was running hotter.
I've been tempted by the new Honda Forza coming out this year, but the soonest I could get one would be the end of September. And there is a dealer just a few miles away. I may just get one for next year and keep driving this scooter the way it is until then, and see if any other problems crop up. I've replaced the battery and all is good there.

[JR]

Kicks on at 4 bars now instead of 3 like it used to,
and shuts off at 3 bars now instead of 2 like it used to.


Sorry I haven't answered on this sooner, been out of town for a few days.

Since the scooter is now 4 years old the changes you mentioned above may also be a thermostat that's getting old and not properly opening or the radiator thermoswitch not properly working either?

On the linhai 250 there are ranges of when the thermostat and the thermo switch open and close and either or one of them could cause this change?

Thermostat

Nominal temp. designation....165 deg F
Begins opening......................157-163 deg F
Fully open...............................176 deg F

Fan Thermo-switch

Starts to close (continuity)....... 208-216 deg F
Starts to open (no continuity).. 196-210 deg F


The thermostat if not properly opening will cause overheat and if the thermo switch isn't closing fast enough to tell the fan to come on then the same result will happen. Simple to find out with a good thermometer and checking water temps.

Also it's a must that you get all the air out of the system when re-filling it after a coolant drain/change.

JR

[wayneb]

I did a lot of riding around town and out of town the last couple of days, and it never went over 3 bars. Don't know why it
was going to 4 bars and even 5 bars once for a couple of days.

Although it stays at 3 bars once it goes to three bars now, it used to go to three bars in town but then go back to 2 bars when
going out of town, now once at 3 bars it stays at 3 bars. I had to order another body part for it so ordered the thermoswitch at
the same time and will see if it makes any difference.

I don't want to spend a lot of money on this because I am really thinking of getting the new Honda Forza that is coming soon. The
Hyosung is a really nice performing scooter, but they don't make it anymore so parts availability may become a problem. And with no
dealer network nearby, it's up to me to fix any problems with it.

[wayneb]

Got a new thermoswitch from South Korea yesterday, replaced it this morning and rode around town for half an hour. Guage never went over 2 bars. Probably won't ride out of town until the weekend so will have to see how it does then.

[JR]

Sounds like you may be on the right track, really hope so.

JR