help with water pump

[thequadfather+2]

I have a problem with overheating. The quad is a 2009 (90cc) model bought new back in March. After my son rode it in the yard about 2 weeks ago the temp light came on. We parked it and after it cooled down I cranked it the light was off, seemed fine. I thought maybe he was lugging it around in the yard and it's 90 degrees out so it just got a little warm. About a week ago I flushed the radiator and looked at the water pump, all seemed OK. I replaced the fluid with honda HP 50/50 coolant. A couple days ago the same thing happened again, when the light came on we parked it. I drained it again last night, flushed it with distilled water and replaced the bottom hose with a clear one and replaced the fluid with minnibike race coolant and even flushed that coolant and put in new so I am sure it isnt mixed with anything else. I also vented the valve on the head and tilted the quad 45 degrees, ran and refilled (no air trapping). I noticed that it does foam a little inside the clear hose and also the coolant doesnt move when it's at idle. When you raise the RPM's the coolant begins to move and gets faster with RPM's. Is that normal? When the quad has low RPM's the water barely moves, if at all. Cant figure out why it would over heat? could it be the temp sensor?

[bulldogfallon]

The water pump is mechanical and is driven from the rpms of the crank.

Do you have a number plate on the front of the quad?


You could also be running lean which can cause over heating as well?


I usually fill the coolant system with the quad running and break the bleeder free and keep adding fluid until I don't have any coming out.

[thequadfather+2]

Thanks for the help, I do not have a number plate on the front but I do have "18" stuck in the front bumper (six inch numbers). I will check the plug, havent had any issues since we bought it from Marc, he jetted it. I changed the plug about a month ago and it looked good.

The next time I drain it I will refill it while running.....For now I will just keep an eye on it. We ran it today for about 15 minutes and all was good. It was only about 80 degrees and he was moving, no lugging around this time and the light never came on.

again, Thanks for the help. It's always good to hear ideas from folks that have more experience with these quads.

[edwardsp&b]

(Quote)again, Thanks for the help. It's always good to hear ideas from folks that have more experience with these quads.




you wouldnt believe the people that has tried to tell me to run apex's. but this is the exact reason i bought and race drr's. there is always somebody helpful to answer questions, and its a relief to know that help is just a few typed letters away:D
bryan