handyandy24 Posted December 22, 2008 Share Posted December 22, 2008 Hey guys another q for u.My bro is trying to get his zzr600 up to scratch alls going well. Hes got stuck though. His fan wasnt coming on when the bike got hot. The heat gauge on the clocks never moved either. Fan didnt react to any input so bust. New fan works and fitted, still doesnt come on however. The thermostat and housing has been replaced. When tested the clocks work fully, the neddle jumps to the top and down like it should on the heat gauge. Wiring is fine. I havent looked at the bike myself just going off what ive been told but any obvious tests they havent tried just point out.My dad mentioned that the top of the rad doesnt get hot, just the bottom. Now correct me if im wrong but is the thermostat at the top of the rad so takes a reading from there maybe why the needle isnt moving up and hence fan never coming on. Could the water pump be faulty/broken and thats why its hot at the bottom but not the top, he can put his finger in the top where u pour in the coolant and its warm but not hot like the bottom of the rad.Fan switch is prob a cheap replacement to narrow down te probs but i cant see how a broken fan switch would stop the gauge going up, again correct if wrong.So is the pump knackered and if so any1 have any experience of this, easy fix?thanks guys Quote Link to comment Share on other sites More sharing options...
Guest Posted December 22, 2008 Share Posted December 22, 2008 have you bled the water system of air ? iirc next to main cap ( under front right fairing) is a bleed screw/nipple) thermostat is also at that position and if air is present this will stop the coolant flowing round ..you got haynes manual ? if not i will have a look at mine later and see if any other little bleed screws etc if thermostat stuck opemn it would take longer to warm up if stuck closed would heat up quicly ...there are two sender units .... a thermostat sender that controls the temp guage and a fan switch that controls the fan ..( mounted on rad ) Quote Link to comment Share on other sites More sharing options...
Guest Posted December 22, 2008 Share Posted December 22, 2008 See the follwoing article, it might help..Copied From ZZR sitehttp://zzr-international.co.uk/forum/vi ... php?t=3999There is another thing to watch out for if experiencing loss of coolant this way. The Cooling fan is triggered by a thermostat switch in the radiator itself, so if there is any air trapped in the system (if it has been drained down and refilled for example) it can result in an partial Airlock,,,,,, the radiator stays cooler than it should, and the rest of the system is hot and preasurised but unable to loose temp, and .......yep the coolant in the closed loop boils/pressurises and vents. Quote Link to comment Share on other sites More sharing options...
Guest Posted December 22, 2008 Share Posted December 22, 2008 there is another bleed screw on the water pump outlet hose refilling/bleeding Fill the system with coolantloosen the bleeder bolts on thermo housing and waterpump outletwhen airfree coolant flows from these ( no airbubbles present ) tighten securely bleeder boltsstart engine with rad cap removed and allow to run until no air bubbles can be seen in the filler necktop up as necessary to top of filler neck replace cap/ Quote Link to comment Share on other sites More sharing options...
handyandy24 Posted December 23, 2008 Author Share Posted December 23, 2008 thanks tim, frankie. will feed that back for them to try. got a feeling it mite do a trick Quote Link to comment Share on other sites More sharing options...
Guest Posted December 23, 2008 Share Posted December 23, 2008 Keep us posted on your progress, it might help someone else in the future.. Quote Link to comment Share on other sites More sharing options...
handyandy24 Posted December 28, 2008 Author Share Posted December 28, 2008 Hey guysI tried that bleeding method tim. at first the bottom nipple wasnt letting anything out but it was just rusted a little. both started draining air free coolant. so i closed them up. turned engine on without the cap on. bubbles at the top, let it run until all dissapeared.engine off cap on. engine on. still the temp gauge doesnt go up. however the rad seems hot at top and bottom and u cant put ur finger in with cap off now.So does this indicate the pump is fine? so it has to be either the thermostat or fan switch. thermostat is off another bike he got it off ebay, cud have been unlucky and boght a duff one? i know u can test these but dont have a gizmo to do it. could it be the fan switch? would this stop the temp gauge going up? :Sthanks guys Quote Link to comment Share on other sites More sharing options...
Guest Posted December 28, 2008 Share Posted December 28, 2008 If you boil the kettle, put the water in a clear jug and then drop the thermostat in it, you should see it open..if it doesn't then its a U/S one. Quote Link to comment Share on other sites More sharing options...
Guest Posted December 28, 2008 Share Posted December 28, 2008 Just a thought...the radiator is on a second loop to the engine.in principal, the first loop is the engine, which is a closed loop via the thermostat, therefore the coolant warms up and maintains an operating temp for the engine, when this loop is at a certain temp the thermostat opens, thus enabling the coolant through both loops and the radiator/fan to aid cooling.if your radiator is getting hot, then the thermostat seems ok. if your temp dial is inopertaive, then i assume a broken connection / loose wire or a duff sensor or dial..does your fan activate...? might need to keep the engine running for a while to raise temp for fan to kick in, unsure of temp settings for switch. Quote Link to comment Share on other sites More sharing options...
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