Hello everyone! I am restoring a '92 EX500 with 25,000 miles on it (yea I know, but I'm 16 and it only cost me $100) and after looking into the coolant resavour all of the coolant looked rusty (normal?). I wanted to drain it but I don't have the manual and my old forums (ex500riders) has apparently been hacked. And since isaac hasn't fixed it yet I was hoping someone could give me a few tips.

 

I'd drain it for sure. The manual says to remove the gas tank (from there I'm not sure of the process). If you can't figure it out once you've removed the tank, let me know and I'll root through my book for the instructions.

Welcome to KF!!

 

Put the bike on the center stand. Remove the radiator cap on the left side of the tank under the fairing. remove the drain screw under the water pump (on the right side of the engine). 8mm socket I believe. Drain all the fluid from the radiator and engine. Tilt the bike slightly to get all fluid out. At this time with 25,000 miles and suspect colouring in the fluid, I would remove the lower radiator hose and put a garden hose into the radiator hose and flush the radiator out. Put the radiator hose back on and fill system with about 1.8 litres of 50% water and 50% radiator fluid. Unless you buy premixed GREEN fluid. Start the bike and let it warm up at idle. When the top hose is warm and there is movement in the open radiator cap area, stop the engine and let it cool down. Top the fluid level up and remove and clean the overflow tank. Fill it up to the level shown on the tank. Check the level after your next ride AFTER it has cooled down. I hope that this will help you.

 

I'd also check the condition of the rest of the cooling system. Look at the hoses, radiator and waterpump. I'd also replace the thermostat just to be on the safe side.

 

WOW! Didn't expect such fast replys!

OK Well I did as you said and removed the left cap and the drain bolt and all of this cruddy red stuff came out. But after all of that stuff came out the reservoir was still full. I think there may be a clog or something somewhere. I was going to try and run some compressed air throught the system, but I thought I may ask for another solution that doesn't have the potential to ruin my bike. [&:]


Thanks!

 

Can you take the resevoir off the bike to clean it out? That way, you can also clean out the tube to it, if that's what's clogged.

 

It is behind the front fairing so I will have to try to remove all of hat first. I will reply when I get it all off.

 

OK I removed the front fairings and exposed the cooling system. I removed the reservior and cleaned the inside out so that it was a nice opaque white. After doing that I then flushed the entire system with some high pressure water, twice. Then I used some radiator flush from prestone and let thatr site in the system while the bike was running for about 15 minutes. After empting that out I flushed the system with water. Then added a 50/50 mix of coolant and distilled water.

And a note about the slow draining system, As it turns out the reservior does not drain as fast as you think. The system was drained, but the reservior was still slowly bleeding off into the system. To 'encourage' it to bleed into the system faster I used a 2 foot length of garden hose and a little bit of hot air from my own mouth to essentially push the non-cooperative fluid out. After it was gone the process was simple. Add coolant to the main cap (on the left side under the inner fairing) and after that is full, top off the reservoir. I let the bike run for 10 minutes and re-checked the level.

Another note comes courtesy of my friend. He got scared because he saw greeen fluid flowing from the bottom from my bike. I just want to point out that usually this extra fluid is coming from an overflow tube that orininates from the reservior. When the bike is under high reving, the fluid can sometimes come out. But do not compensate for this by under filling it! After a while the level will go down. This is necessary because there might be air left in the system that needs to be filled.

So there you have it, that is all of the knowledge that I have on the subject of flushing coolant on the EX500. If done properly, with the right tools and knowhow, this could probably be acomplished in under 2 hours. Thanks for all of the help, and I hope that I have been a help as well.

--KClaisse