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Post by danielphil10 on Aug 7, 2015 20:48:44 GMT -6
Hello guys,
I know that most of you are expert on Chinese scooter..
So here is my story ( I never had a Scooter or a bike before I do not know a lot about scooter or any mechanical background)...I just bought a used 2011 250cc (244c) Jonway and it has 800 miles on it, which is no a lot at all ( I bought for a fun cruise during weekend with my wife).. I bought it and drove it for couple of days.. After that one day for some reason the temp gage starts to rise up to the red line (Overheating), also I notice the cooling fan is not working anymore so I would stop every now and then to cool it off... at night the scooter runs on 3/4 temp gage reading... but if the scooter is on and not running, it get overheated quickly... long story short... one day I decide to start the scooter for a quick ride, scooter wouldn't start.... I thought the relay was bad and wouldn't kick start the scooter, so I decide to take the relay out and paypass it by sparking the positive of my battery to the red line that connect to the engine starting.. and it sparked engine and it starts running AGAIN !!!!!.. I start to ride it for a quick coupe of mins I notice the Temp Gage is not working anymore and I guess it got hot and the coolant expansion tank suddenly started to burst coolant out!!! turned the scooter off and left it for day... then the next day I decide to start the scooter to see if still running and it works fine so i left the scooter alone... so I did some search and I start taking the scooter covers off so I could reach in and see where that coolant came from... so I stripped the entire scooter!!!!... now I am able to see the entire scooter from the inside and it still runs (somehow haha)... so I did more search to see why my temp gage is not working how did my coolant burst out... here are some tests I been doing.. I check the radiator thermostat by a meter reader and its working fine.. I flushed out the entire cooling system and put a new coolant liquid (50/50) and I air bleed it
very good to make sure no air trap..... I tested the radiator fan and it works fine too... I checked the water pump and its clean..... I don't know why my Scooter is acting like that... I need some help on how can I fix my Temp gage and get it back to work so I can ride it? please advise, also a pics will help a lot me to understand since I am new to this.. working on that scooter taught me a lot and I enjoyed.. I just need a guide.. Thanks
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Post by JR on Aug 7, 2015 21:14:35 GMT -6
 danielphil10 If you're sure it's bled good and has no air in it then you're good to go there. Now the temp gauge has 3 wires 12Vdc generally a black wire Ground which should be green A third wire going to the temp thermo sensor on the engine, color varies but blue/yellow is common. Need to see if you have very good connections to all components so if you have it opened up that should be no issue? Check for 12vdc to the temp gauge Make sure all the wires in the entire cooling circuit have not been severed. If you have voltage, no bad wires or connections then the thermo sensor sending unit on the engine is bad. JR
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Post by ellpee on Aug 8, 2015 7:16:05 GMT -6
If the temperature gauge is in fact moving, then the temp sensor on the engine is likely okay. Mine went bad, and the gauge just sat on the lowest reading no matter how long or how fast I ran the engine. Or, if I pulled off the wire and grounded it somewhere, the gauge went all the way to the hot end.
The problem you describe sounds to me more like a bad temperature sensor on the radiator itself. That gizmo is supposed to turn on the fan when the coolant reaches a certain temperature, something like 165 degrees I'm told. If it is defective, or if the wires to it or from it to the fan are defective in some way, the fan will not turn on when it should, the coolant temperature will rise, and sooner or later the engine will overheat (and be damaged!!!). Easy enough to check the wire that brings 12v to it from the battery/fusebox, but to check the "out" wire that feeds 12v to the fan, I suppose you'd have to remove it and put it in a pot of very hot water or something.
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Post by danielphil10 on Aug 8, 2015 7:29:25 GMT -6
Ellpee, I check the radiator temp, by unscrewing it out, heat it, and did a meter test to when it was hot, it read from 600 oms going down to zero.. SO I think the radiator temp sensor is working fine.. I need to check if the temp gage is woking fine or not before I check the thermostat on the engine.... I just don't know how can I check the temp gage with the meter test.... danielphil10, JR, ellpee |
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Post by danielphil10 on Aug 8, 2015 7:33:51 GMT -6
  I post this two pics to see if I am talking about the right thing or not First pic is the radiator sensor and that was taking out and done a test to it... second pic is the thermostat... and that will be my last step to check... |
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Post by danielphil10 on Aug 8, 2015 12:40:10 GMT -6
Okay, here are some updates.... The temp gauge is working fine when I ground it... Some how the cooling fan is working now too... So that means my radiator temp sensor is good... I check the wire that connects from the engine thermostat sensor to the temp gauge and it working fine... So now my only hope is the engine thermostat... I am very close to fix this scooter... Please advice me... Thanks
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Post by JR on Aug 8, 2015 17:04:13 GMT -6
The first picture is the radiator thermoswitch sensor. Simply put when the radiator comes up to temp it by heat action conducts just like any switch and turns the fan on. When the water cools to the temp below it's cutoff range it disconnects and turns the radiator fan off.
The second picture it the temp gauge sending unit sensor. Now the magic word "The temp gauge is working fine when I ground it..." The grounding wires on these scooters sometimes are really a mess and cause multiple issues. More than likely in the wiring harness you'll find a bundle of green wires all connected by a brass crimp connector, they are notorious for losing connection.
Check your ground wire to the temp gauge by tracing it out to it's hook up point, check the ground wire to the frame from the battery to make sure it's making a good connection,
Yes you are close.
JR
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Post by danielphil10 on Aug 8, 2015 21:35:05 GMT -6
okay I worked for 12 hrs today on my scooter trying to find out why the scooter is acting up like that so JR ....on the bike frame I found three connection the screw on: two are black lines the third one was green, but the green was cut off and not connected at all... when I connected it: I could start my scooter by the start button... and that lead to a discovered that my Rely (solenoid start) is working fine... ( I thought it was not working) also that green wire was the cuz of the fan not picking up to work during standby mode..... so now everything is working fine... but for some reason the temp gauge still not working... but there is something wired I discovered... the tempo gauge has three wires as JR mentioned... when I ground the dark green wire the gauge boost up and then drop back to low... when I crank the scooter is does the same thing... but there is a weird thing I discovered.. when I turn the scooter off and leaving it on standby mode (right before pushing the start button to crank it ) and ground that dark green wire ( one of the three wires that connects to the temp gauge ) the gauge boost up but all of the sudden it reads the temp. of the engine but when I crank the scooter it drop off... this just driving me crazy... now i am very closeeeee...... so I think everything is working fine on my scooter...... except that temp gauge reading.... so to recap everything : 1. radiator fan is working fine... ( after ground a green wire to the scooter frame) 2. radiator temp. sensor is working fine ( fan turns on when the radiator temp. sensor reaches the required temp) 3. engine thermostat is working ( because the radiator both pipes (top pipe which connects to engine & bottom pipe connects to water pump ) they get soft and hot... 4. engine thermostat is working fine ( I think because of #3 ) 5. rely working fine..
so why my temp gauge is acting up like that....
danielphil10,JR,ellpee  picture of the temp gauge connection.. as Jr mentioned... Please review and advice... we are very close |
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Post by JR on Aug 8, 2015 22:31:31 GMT -6
Turn the key on and test the black wire on the temp gauge for 12Vdc+ voltage. Test it by touching one lead of multi-meter to black wire and the other lead to a good ground, then test it by putting it on the green wire on the gauge to see if it's a good ground wire? If not then trace out the green wire until you find the problem.
Already hooked up a loose green ground wire, there could easily be another.
JR
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Post by ellpee on Aug 9, 2015 7:16:41 GMT -6
So I'm getting a little lost here. In the beginning, you WERE getting overheating, right? And the temp gauge WAS working, because you said it rose up to the red line. And the fan was NOT turning on.
In the meantime, you have checked various things and determined that fan, radiator temp sensor, engine temp sensor, and thermostat are all working. If that's the case, you should no longer be overheating, and your only remaining problem is that the gauge reading is unreliable? That'll be something electrical, as JR has said.
Humor me -- disconnect the wire to the ENGINE temp sensor, the one that screws into the cylinder head, and ground that wire directly to the frame. The temp gauge should instantly peg at the high end. The way that sensor works is to provide a variable ground; when cool, very little current gets through, but as the engine heats up, more and more current flows to ground, causing the gauge to read higher and higher. Grounding the wire directly mimics a very hot engine, which should cause the gauge to immediately go to redline. That wire should be one of the three that connect to the gauge. The 12v in wire serves two purposes: provides the juice for the light inside the gauge -- that's what the other ground wire is for -- AND provides the juice for the needle, which gets its ground via the engine temp sensor. If that sensor, or the wire leading to it, has a problem, that would perhaps explain the crazy readings you describe.
PS -- don't mistake me for an electrician. This just happens to be a problem I struggled through a few months ago, and I'm sharing my experiences.
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Post by danielphil10 on Aug 13, 2015 23:04:42 GMT -6
JR How should I step up my multi meter so I can do that reading ? Do you think installing a new temperature gauge would be a better choice then trying to trace all those crazy wire... That wire harness is a miss and it's driving me crazy... ellpee, when you mentioned cylinder temperature sensor... I got confused... Is there a way you could explain by picture? i only know two temperature on by the radiator and the other by the thermostat.... I am sorry guys I am new to scooters in general ... And sometimes I just get stranded... i am starting to put the body cover back on... I thinking about riding it like that without temp. Gauge "can I do that" JR ellpeethanks DP |
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Post by danielphil10 on Aug 13, 2015 23:20:23 GMT -6
Another point I forgot to point out maybe that would help... When I crank the scooter and take it for a test when I give it gas my gas gauge drop low when I break is raises up.... Is that because of acceleration and sudden stops? .... It wasn't doing that before all of the above problems....
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Post by ellpee on Aug 14, 2015 6:57:07 GMT -6
Another point I forgot to point out maybe that would help... When I crank the scooter and take it for a test when I give it gas my gas gauge drop low when I break is raises up.... Is that because of acceleration and sudden stops? .... It wasn't doing that before all of the above problems.... Just my guess, but it sounds like the fuel is "sloshing" in the tank and causing the float to bob up and down. Fill the tank all the way up and see if it does it then. If it still does it, my guess is wrong, and JR or somebody will have to chime in with other possibilities. |
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Post by ellpee on Aug 14, 2015 7:08:26 GMT -6
JR ellpee, when you mentioned cylinder temperature sensor... I got confused... Is there a way you could explain by picture? i only know two temperature on by the radiator and the other by the thermostat.... thanks DP The scooter I have access to at the moment is a Magnum trike, considerably different from your Jonway, so a picture wouldnt be much help. Probably the sensor by the thermostat is the one I'm talking about. It screws into SOMEWHERE on the engine so it can sense the temperature of the coolant circulating inside, so the thermostat body would be a logical place. It should have just a single wire leading to it. The OTHER end of that wire will be one of the three that connect to the back of the temperature gauge. (Pay attention to the wire color.) You can actually do what I suggested in one of two ways: disconnect it at the sensor end and touch it to any good ground, or use a jumper wire to ground that connection at the gauge end. Either way, watch what the gauge does -- it should peg all the way at the "hot" end, and when you stop grounding it, it should drop back to the "cold" position. If it doesn't, time to suspect a bad gauge. |
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Post by danielphil10 on Aug 14, 2015 10:52:05 GMT -6
ellpee I think I done that test before... but my test was like the following I unplugged and ground the wire and it peg the Temp. gauge ( the connection was two wire connected to a metal piece that plugs onto the thermostat temp. sensor) so did I test that wire right? ![]()  that pic shows what I am talking about that wire connection. Thanks
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