93 900rr, riding on the highway, feels like I'm running out of gas, tank is full, pull over and coolant is dumping from the overflow, and now I can here a knocking noise when I Rev it up. I'm not seeing oil in the water vise versa, I don't have a stethescope on hand but I'm wondering if these have belt driven water pumps and if when they go out do they make a knocking noise. any help would be appreciated

 

so apparently the water pump is just under your foot on the left side, its shaft driven, im thinking the knocking sound is coming from it. it actually sounds like bad bearings like on a skateboard wheel or something similar. the problem is defiantly an overheating issue and this is the only thing i can see in the coolant system that could be the culprit. really hoping i didn't mess anything major up with the overheating

 

Don't run the bike for any prolonged period till you get this figured out or you can cause major damage.
Start/run it for short periods, as you check various possibilities.
Constantly check the temp-guage and shut down if it gets close to being too hot.

Heat issues can be frustrating to diagnose, so take your time and don't push the system, till you get it figured out.

First thing to check is whether the thermostat is stuck (either partially or fully closed).
Top off the coolant, as well. Replacing the pressure cap (in case it is weak and
'popping' early), is an in-expensive option, as well. Feel the hose on the out-put side
of the radiator (the right, I believe), is it getting warm? i.e. is coolant flowing through.
Does the radiator get warm? i.e. is coolant flowing into it?

Here's some links to illustrate the entire system...

HONDA OF TULSA 1993 Honda Street Bike CBR900RR Parts List

HONDA OF TULSA 1993 Honda Street Bike CBR900RR Parts List

HONDA OF TULSA 1993 Honda Street Bike CBR900RR Parts List

There's not a lot of options with the pump, itself. It either works and the bearings are good
or you replace the entire unit. You can drain the coolant and oil and pull the pump unit.
About the only test is to turn the unit by hand (after removal). If it has any resistance/roughness,
it probably needs to be replaced.

Hope this helps, Ern

 

so an update, I tested my thermostat it works, my rad cap wasn't holding any pressure so i replaced it, and the water/oilpump works. Ive never seen a bad rad cap be the cause of overheating issues but whatever it might have been. I didnt notice that the carbs werent seated properly against the engine maybe air was getting in there and causing it to run lean. i let it run for 20 min and it never overheated, the fan came on when it got hot and turned off when it dropped back down. there are now two different knocking noises, one sounds like its coming from the top of the engine and the other bellow but one of them will stop occasionally, the carbs seem to be in working order. I drained the oil and didnt see any metal or water in it, im going to drop the pan and check the bearings down there. Im wondering if its possible to replace rod bearings without tearing the bottome end apart. im thinking the clicking from above is maybe a valve lash issue or maybe i burnt one during the over heat and its not seating properly anymore. if you have any more ideas madhattr then let me know.