Please help with Airlock in cooling

[monty57]

I am not sure if I was just lucky or what but after the coolant system was flushed (early) I did not have any of the the issues talked about here with cooling. Even when riding two-up the gage would go the middle and stay there. I never noticed much fluctuation at all. The only time I ever had an issue is when i let it idle for a very long time in the garage. Then the temp went quite high before the fan finally kicked on. Other than that one time it has always seemed to do the job correctly.

The thing that may be a clue here is the radiator location. The Roadrunner radiator is located directly behind the front wheel. Ihave heard that some of the radiators are located elsewhere under the scoot.

The Majesty I recently purchased also has the radiator located behind the front wheel. Even in the 104+ temps we have had recently it goes to the middle and stays there. I rode the Roadrunner for a short distance over the weekend in the 100+ heat and it did well also. Right to the middle of the gage and there it stayed even under some pretty hard riding.

I guess what all this leading to, is there a dependability issue with the Thermostat, fan switch or sending units that are causing the erratic issues some guys are having and can they be cured by replacing these parts with some of known quality?

[scooterollie]

Monty;
No doubt, with the radiator located just behind the front wheel, there should be better air flow while in motion and less need for the fan. My Bali CFMoto 250 has the radiator behind the gas tank. While the cooling system functions properly, the fan is involved more at speed than in my Linhai 300 with front mounted radiator. On the Linhai, after passing through the radiator, air is directed beneath the gas tank, between a metal plate below the tank and a plastic under-belly pan.

[MLN]

mln said:

I've worked on some difficult to bleed dirt bikes and street bikes. Here is something that is very simple and will usually net progress.

With the engine off lean the scooter over to the side slowly. Sometimes you have to nearly lay it down. Do that in both directions. You may hear the water rush around inside the lines/engine. Burp it and refill a couple times until it is full.

If it doesn't work with the engine off try it again with the engine running. BE CAREFUL if doing it with the engine running. It would be easy to twist the throttle and launch your scooter. Two people would be best. Obviously you won't be able to hear the burp if the engine is running. You'll just have to check the level to see if it helped.

Jay

Did you try this? Did you hear any burping? Did it work for you?

[jaysinet]

MLN, actually my friend and I tried a variation of that several times and I am not sure how much it helped or not...it may very well have done the trick, but I don't know for sure because we were always trying to get it right and sometimes we would try a couple different things at once and the re-test it each time. I think in the end, it was a mixture of flushing the system several times to get all that sediment out of the junky little radiators, and then bleeding the coolant hose as best we could. Maybe in the end, it was just a matter of getting the motor a little more broke in.
And oh yeah, I could not actually hear gurgling.

[YellowScooter]

Hey for what it's worth, I used to work at a Jiffy Lube in Jacksonville NC and they have whats called a 'power purge' coolant flush system. It flushes the radiator engine block and heater core (on cars, bikes obvoiusly dont have heaters). the system runs on gravity and the cars/bikes water pump. I think that would work to get any bubbles out of the cooling system. plus it'll get every drop of the chinese crud out of the bike.
It's a thought.