logic fail

 

Is your water pump working? You can check by:

1) with bike cold, open the radiator cap. You can reach around from beneath instead of taking the fairings off.

2) start bike, watch inside the radiator.

3) Rev bike up and down a few times. (like they usually do in exhaust sound vids)

4) coolant should appear to suck down when first revved. Indicating that your pump is truly sucking.

Oh, and is your thermostat any good? I haven't a clue how to check, but that could be the whole problem right there.

 

Mine does the same, I'm in Tulsa and over the last month or so its been in the 90's, when I'm riding its running about the half mark, if I sit at a stop light, it moves up to 3/4 or so and the fan kicks on, I figured that was normal.

-Ian
1994 cb4600
42k miles

 

It's perfectly normal for the temperature to go up if you're slowly riding through town or stopped and running. It will go up so far and then two things should happen: your fan should kick on to blow air over the radiator fins and your thermostat should open up allowing the water/coolant to circulate replacing the hot coolant around the engine with the cooler fluid in the radiator, thereby lowering the engine temp. This is why I would NOT recommend running your bike without any fluid in it at all.

 

Im a bit paranoid my coolant pump isnt working. I took off my rear right fairing to get a better look at the coolant bottle. Started her up and rev'd while watching the level. It did go down but only about 2-3mm but when I looked into the bottle while reving I noticed the engine vibrations cause fluid on the surface to bounce off the edges of the bottle. Which may give the impression the levels dropping.

I also took of the front right hatch on the main fairing and squeezed the hose that comes off what appears to be the coolant pump. When I rev'd the bike I didnt feel any pressure increase.

I've never had a problem with overheating but then again Ive yet to drive the bike slowly in traffic. At what point on the temp gauge should the fan kick in? Would it be an idea to leave the bike idling until it kicks in, just to see if it works?

 

If you're concerned about it, then that is what I'd do. Start it up and let it idle for as long as it takes for the engine to get good and hot. I'm not sure about the exact temperature the fan kicks on, but I'm pretty sure mine is somewhere between 1/2 and 3/4 on the guage.

 

I bottled out after 11 minutes of idling. Although the Temp gauge only showed what is below I could feel the heat radiating up through the front of the bike. The engine was at the point where it was untouchable but I could place the back of my hand on the radiator and although it was uncomfortable it didnt burn.



I then proceeded to take off the left rear fairing to get a better look at this coolant bottle. I noticed the hose running into the bottom of the bottle (numbered 2) and gave it a feel. Wasnt even warm. The hose at the top of the coolant bottle next to the opening, what purpose does that serve? I also couldnt spot a return line on the coolant bottle (is there one?).




On another note, when the bike refuses to cold start. If I blow into the hose numbered 1 and put my finger over it to stop the air rushing back out. The bike will start first touch of the starter.

I only recently passed my test and in the weeks worth of riding Ive done the thermo hasnt went past the 1/2 way mark. Maybe its just me being paranoid.