Hey everyone,

I'm working on a project bike I picked up that wasn't running. Anyways it runs great now! It's going strong and all that, and the carbs were easy enough to redo. I'll be rejeting the shortly as well given that the bike has an aftermarket exhaust and a K+N filter on the intake.

Anyways, while letting it sit idleing today, I noticed the engine temperature got a decent ways up there. It's not at all abnormal for an engine sitting for 20 minutes just running to get a bit towards the hot size, I know as it happens on all the bikes I've had and my friends have when we get stuck in traffic. Anyways though, I turned the motor off with the kill switch, but left the bike on to keep the fan running.

...only the fan wasn't running.



So, what am I looking at here? I presume first simply connect the fan to the battery directly to test if it goes at all. From there I'd presume it's sensor related, and requires checking voltage off the sensor. Anyone know what voltage I should be looking for on it?

Btw, I have the haynes manual. They left this out of this section. Maybe some one has the honda service manuall!

 

Best way to check it first is to ground the sensor connection from the left side of the radiator to something. The fan should spin.

If it does, the sensor is bad. If it doesn't check the wiring back to the fan. If it looks good, then pull the fan and put voltage to the connector.

My original fan was bad. I changed it out with one I had from a parts bike.

Good luck.

KongBastard

 

Good advice, and thanks! Ground the left of the sensor... alright I'll try and do that!

We're talkign riders left of course, correct?

 

Maybe a dumb question.. but did you make sure the coolant level was up to where it is supposed to be? I had a non-running fan issue when i bought my bike and this fixed it for me.

 

The coolant is all the way up to the top of the radiator as far as I can tell. I remove the cap, and there is coolant right there.

 

Hey, so let me double check to make sure I went about this right...

First off, you have to remove the connector to the sensor, and then ground it to the frame, with the key on. Motor doesn't need to be running. This should cause the fan to kick on, correct? I also tried re-hooking up the sensor and then running a wire from the sensor to the frame. NOTHING!

Also, getting to the fan looks like a massive headache...

 

You have to pull the rad.

The coolent level is checked by looking at the reserve bottle on the right side by the rear master cylinder.

KongBastard

 

Does the fan spin freely when you try and spin it with your finger? You should be able to get your fingers in there pretty easily with one of the side fairings off. I live where my fan doesn't have to run much and it got corroded in place and blew the fuse.

 

Yeah... to get my fan to work properly, I had to add a bunch of coolant to the reserve tank - Kong is right - pull of the plastic on the right hand side and you can just pull of the rubber lid... I added a bit over what the marking called for, then ran the bike and it did go lower.

 

Alright, well it looks like I'm dumping the coolant, pulling the fan, checking the fan, and then refilling everything including the resevoir. Might as well since I won't run it until I finish the exhaust fiasco!