Hi all How do i best go about draining the coolant on my gj72a? Ive got rust in the system as the PO apparently just used regular tap water to refill.. So needing to do a flush, ive got a bottle of coolant system rust remover/flushing fluid but am in doubt about how to do it the correct way. My shop is almost an hour away from home so i havent seen the bike in a month or so since ive been waiting on parts for the carbs. As far as i understand the impeller housing should be accessible from the left hand side of the motor, is it as straight forward as disconnecting one of the hoses there and trying to flush as best i can with water (engine off) before filling with rust remover and letting the engine run for a bit to circulate completely? then letting sit for a bit and then flushing again and refilling with proper coolant? Best regards, a crazy (stupid) dane
As you have written. I take off a hose at the lowest position and flush with garden hose both ways (into engine and into radiator, take off the rad cap too) until water runs clean. Then replace hose and use the rust cleaner. I would do about 50Km to be sure the cleaner has got around to all the corners of the water system and drain as soon as you return from the ride (be careful not to get burnt from the hot water) so that any rust flakes/particles are still floating and not settled. When cool flush with the hose again until clear and then fill with the correct coolant for your bike. Don't forget to flush the overflow bottle too.
I would drain it via the lowest point on the engine, maybe have a look across the front lower section of the cylinder's and see if there are any drain bolt's there. Then refill with some new demineralised water, start the bike and run it up to normal operating temp's and drain it again a couple of time's Then you can redo it with the rust remover and once that's been flushed a couple of time's fill it with coolant, rock the bike from side to side a few time's to burp the system before fitting the radiator cap
Water pump should have a bolt with a copper washer - this is the drain bolt. Remove radiator cap and bolt, bike on side stand with a suitable container. Flush with garden hose at first, top the bottom, then bottom to top. Just be wary of electrics. Use water and descaler that you can buy and follow the instructions to the letter. If necessary, the radiator can be removed, tested, cleaned, repaired and refitted. The local bloke here in Sydney does them for about $120.
