jonway250 overheating (head gasket) By trvstlh (Read 977 times)

[trvstlh]

Hello there i have the jonway 250 (like Cruiser's) i've changed the radiator, thermostat, fan switch, etc. the bike still overheats, once running and coolant flowing, should ALL 3 hoses become a little warm/hot to touch?? could it be the HEAD GASKET?? if its the HEAD GASKET should i NOT have have other running issues? or it would run fine until it begins to overheat? thanks in advance

[vintner]

When I think head gasket, I think either coolant fluid getting into the oil or oil getting into the coolant, a loss of pressure in the head, and finally smoke usually at start up when oil or coolant gets into the cylinder and burns off when first started.

If the coolant is suspected of not flowing, it can be checked by disconnecting one side of the scoot radiator hose probably near the fill. Connect a garden hose to the scooter hose end that was removed. Turn on the garden hose to a low flow. If the water doesn't flow, the thermostat could be pulled and (I think) left out when the unit is assembled. Retry the garden hose flush. You should get water through the radiator and engine and dumping out the radiator fill cap. If you don't, something is plugged. If you do, (if the old method still works) you may want to check the thermostat with hot water on the stove to see if the thermostat opens at higher temps.

Hope I am not giving bad advice, but the cooling system isn't that much different than a car cooling system. It should be able to be verified about the same way.

[trvstlh]

Thanks gut, will try anything right about now.

[vintner]

Another comment on your other thread about the pump. I had a pump on my rental property boiler where the motor would turn but the impeller would spin freely on the motor and no water would be pumped.

Scooter water pump is different, and yet the same. I don't know if it could happen that the impeller isn't fixed to the shaft, but if the shaft would spin without spinning the impeller, then you would have the problem of over heating (where the impeller not spinning at my rental property meant that they didn't get heat).

[Bashan]

That's good advice Vintner, a cooling system is a cooling system...big or little. Trvstlh, if you can expose the radiator cap (not reservoir) take it off and watch the coolant, it should swirl when the thermostat opens. The thermostat check in hot water is a valid one also. How do you know it's overheating, by the gauge? That could be suspect. Get a probe thermometer, an oven type will do. And measure the oil temp after you think it's too hot. It's not the head gasket, I'm sure of that. Rich

[Alleyoop]

If it was the head gasket you would be blowing smoke out the muffler and or dripping fluid.
Alleyoop

[trvstlh]

Thanks guys for all the advice, i will check the oil temp. also, what should the temp. read? also are you saying the gauge could read HOT and it NOT be hot? what switch/relay controls the temp. gauge, this could be bad right?

[trvstlh]

ive located the head gasket i purchased a few years ago, theres a metal 1 and a paper type 1 in package, top of head uses the metal 1, after taking off top of cylinder i noticed the previous metal gasket is extremely thin,(alot thinner than new 1) would this have caused a problem with overheating

[vintner]

No.

It is thin because the screws are normally torqued to the manufactures spec that compresses the gasket so it does the proper sealing.

If you are not seeing a break in the gasket, it is doing what it was designed to do, seal the cylinder to the head and provide passage for the coolant. I think pulling off the head was an unnecessary step.

[trvstlh]

THANKS FELLAS FOR ALL THE ADVICE, HELP, ETC.ETC., AS I STATED B4 I FOUND THE HEAD GASKT I PURCHASED IN 2009 (DATE ON PACKAGE), CHANGED IT YEST. MORNING AND BIKE RA FOR 1 HOUR 45 MIN. WITHOUT OVRHEATING AT ALL, 2DAY GONNA START CLEANING HER UP AND PUTTING BODY BACK 2GETHER. THANKS AGAIN I CAN'T WAIT TO RIDE AND SEE HOW SHE DOES.....DID I SAY THANKS