yamaha tzr 125 over heating problem plz help

[muffy]

hi my mates got a tzr 125 it over heats all the time he has stripped down the hole system water pump working
no blockage in rad and thermosat working
when he trys to bleed the system no water comes through
we have been working on this for a while now and had no results there seems to be no flow from the radiator even the expantion tank under the seat has dropped in level but if we we take the hose of the top of the head that leads to the thermostat theres no water coming through
we just cant get the water to flow if we take the rad cap of the temp goes down a bit but under presure it goes up to the point where we have to switch it off to save the lump from cooking
any help whould be great its a mind bender i know but you boys aint failed me yet so i thought idd give ya a go

[nightshaddow]

best thing is to start from the top pull them all off and check every hose every tank and radiator in the cooling system,

start with the thermostat drop it in hot water (from a kettle, at boiling point) if it opens its good if it stays closed its not

take of the header tank and flush it out then fill it with water check it and check it all drains out with no clogging (if no water comes out see why not that your problem.

next the hoses once removed just attach a hose and sprey water through if it builds presure and blows back water theres your problem,

next you need to check the radiator, take it of the bike and fill with water make sure all the water drains out every outlet without blockage,

then the cylinder with all the water system removed fill the cylinder water chambers with water make sure it flows in and out smoothly.

my money personal would be either on the thermostat or put together wrong once you have checked all these rebuild the water system taking care the hoses and everything are in the right place and the water is traveling the right direction, dont forget your anti freeze its cold out there, if you still have the problem if no one else has any suggestions its time for a garage
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"WHAT DO YOU MEAN 100 MPH THATS IMPOSSIBLE Its chinese OFFICER."
Current rides CB 125 TDE(the next project) NS125RK ( now on the road ) CB125TDC (soon to be project 17) melody ( the nephews )

[lukamon]

check to see if the are any bleed screws you missed - for example on my old kmx the cylinder maybe 15 degrees which meant you had to open a screw on top of the cylinder and take the rad cap off. water would rise up with nothing coming out of the hole for a few secs, then water came out and you screwed it back in
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killa wrote: Im an ass man myself