slack Posted May 7, 2012 Report Share Posted May 7, 2012 Hi everyone, my Gas Gas 300 raga 05 is leaking coolant from the over flow pipe,its been doing this for a while so i changed the rad cap. thought this had cured it until when out yesterday i noticed it was dripping from pipe again.so today changed 'o' rings in the head but while trying it today i noticed the fan was not running as it shuld. when its on the fan seems to be running ok then it has a drop in power then picks up again.any one had a similar problem and what was the cure. THANKS. Quote Link to comment Share on other sites More sharing options...
tankygsy Posted May 7, 2012 Report Share Posted May 7, 2012 Sounds to me like your fan motor is at fault. Try rigging the fan motor up to a 12v dc supply, for instance a car battery and some small jumper leads probing the fan terminals, and make sure it turns on every time. Try several times to see how it acts. Mine had this fault where it would only come on 4 or 5 out of ten attempts and i ended up replacing the motor with a graupner speed 500e motor, £12 from cornwall models. Worth noting is that you only need to loose a little bit of water from your cooling system and it renders the thermostat useless as a switching device due to the thermostat being so high up in the system. Quote Link to comment Share on other sites More sharing options...
mudboy Posted May 8, 2012 Report Share Posted May 8, 2012 I had the same problem on my brand new 2011 300 racing. Spewing water out of the overflow, got a new rad cap that did the same. The problem was that one of the rubber"O" ring seals on the head was leaking. Replace both rubber seals and your troubles will be over. Its probably bleeding water into the barrel. Quote Link to comment Share on other sites More sharing options...
sting32 Posted May 8, 2012 Report Share Posted May 8, 2012 Hi everyone, my Gas Gas 300 raga 05 is leaking coolant from the over flow pipe,its been doing this for a while so i changed the rad cap. thought this had cured it until when out yesterday i noticed it was dripping from pipe again.so today changed 'o' rings in the head but while trying it today i noticed the fan was not running as it shuld. when its on the fan seems to be running ok then it has a drop in power then picks up again.any one had a similar problem and what was the cure. THANKS. Hey I got a couple or so guesses, and suggestions... Are you filling the radiator each ride? if so, some might blow out as it gets to the "Level the coolant system prefers", so maybe monitor this, by checking (VERY OFTEN) during a few hours riding? of course, after you let it cool, seems to me as long as you can see fluid above the fins part of radiator, you will be fine, if all else is up to "snuff" so to speak. Have you ever done the water pump kit or inspection? I read on these boards in the past, that people take the pump apart and the impellers's fins, were gone off that pump, which is plastic. Might be worth a check? water has to circulate at a good rate ya know, or it is going to boil quicker than the tiny cooling system can take. Somewhere, either on this board or another, someone had issues with the "voltage regulator" which somewhat vaguely sounds like you "might" have, usually the fan quits runing at all I believe... that is if what you say is true, if fan seems to lose power, instead of the fan itself being OLD AND WORN OUT and cant run right. So like previous poster said, maybe unhook the fan, run it off a car battery for a bit, and hopefully tell if the fan motor is good, quitely running (example no bearing noises etc). please note, most of my bikes lose a tiny bit of fan speed at idle compared to anything above idle, so that could be normal, hard to say when I am not there to see/hear it. The water jacket is the head and the cylinder nothing else, & those 2 orings are critical, and you have to be pretty sure you get them right, usually you have to hold the orings in place with a tiny amount of grease, not silicone!! One more thing, jetting or even dirty carb jet, can be an issue, cause too much heat if you are lean, and boils water out, and in near or even past dangerous levels, it used to burn the Nickel plated exhaust headers into a blue tint. Be sure you arent lean, use good fuel. Quote Link to comment Share on other sites More sharing options...
slack Posted May 8, 2012 Author Report Share Posted May 8, 2012 Hi guys, yes i have changed the rad cap & yesterday changed the 'o' rings.I thought it was the water finding its own level but after monitering it for a few weeks belived this was not the case so bought the new cap & 'o' rings.After fitting the cap a few weeks ago i thought i'd sorted it but it was still dripping on sunday so i fitted the 'o' rings yesterday but while testing it yesterday i noticed the fan was not running as it shuld. i will test it with a 12v battery to see if it runs smothley & without any voltage drop.i might try a regulator.Thanks for all your replys. Quote Link to comment Share on other sites More sharing options...
mudboy Posted May 9, 2012 Report Share Posted May 9, 2012 I have heard that if the coolant level is to low the thermostat does not work properly switching the fan on. Quote Link to comment Share on other sites More sharing options...
gilbertdave Posted May 9, 2012 Report Share Posted May 9, 2012 I had the same thing last year.... I actually had two problems, so I'm not certain which one fixed the problem. I was leaking fluid from the overflow pipe, but it wasn't clear if this was spitting because the bike was getting hot. I notice the fan was intermitent. It would start up, but cut out from time to time... I also notice it would speed up and slow down based on engine speed (revs)... I replaced the rectifier and this seemed to go away. I also noticed a hairline crack in my radiator which could have prevented the radiator holding pressure... hence boiling over and spuffing out of the over flow. So I also replaced the rad. I woudl recommend testing the fan with a 12v supply as others have mentioned, then definitely try the rectifier before you start spending mega bucks! Good luck Quote Link to comment Share on other sites More sharing options...
Metalgrainz Posted May 9, 2022 Report Share Posted May 9, 2022 Hi, I have a Raga 300 2008, it currently has a coolant leak from between the two main crank case halves. As they are metal to metal sealed. Does anyone have any suggestions on a solution to this? Is it a known issue etc Quote Link to comment Share on other sites More sharing options...
richt Posted May 10, 2022 Report Share Posted May 10, 2022 The way you have described it, coolant cannot leak from between the crankcase halves. Quote Link to comment Share on other sites More sharing options...
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