[ShtNgiT]

Ok, here i am, spent a small fortune buying parts to fix this cooling issue for my SP1

Here are the facts:

The bike had cooling issues before I took her apart. She would run nice and cool on the freeway, but heat up quickly on the slower paced roads, but nothing overheating, unless Telegraph cruise, where i sat and i sat and i sat, having to pull over, and turn the bike off.

So, with that being said, I had alot of work recently, and decided to take apart the bike and find the necessary issues. I am mechanically inclined to do the work, and have a pretty good knowledge of how things work.

I noticed, that when I did my investigation, that there were two pretty big issues mechanically:


1. Thermostat was stuck wide open: giving the impression the coolant had no time to cool down when the thermostat stayed in the wide open stuck position, hence constant hot fluid would be running through out the system.

and

2. The cooling fan for the radiator was not working properly.

So, I ordered the new parts; the thermostat from Kevin ( great job btw Kevin), and ordered the new/used fan/motor from a local vendor.

The thermostat matched the part numbers that came in the manual, and the fan was in working condition
Now,

Installed the new thermostat, and cooling fan. Filled up with new fluid, blead out the air and let her run.

140, 150, 160 (thermostat begins to open, and it did, the temp hovered there for a while) 170, 180,190, 200, 210, 220 (fan should have come on), 225, 230, up to 250, NO fan coming on.

Coming to the conclusion the fam temp switch may have failed.

Removed the fan temp switch, called Rosenau, which happened to have one, and installed the new one. Restarted the bike.

140, 150, 160 (thermostat begins to open, and it did, the temp hovered there for a while) 170, 180,190, 200, 210, 220 (fan should have come on), 225, 230, up to 250, and NO fan coming on.

I have checked electrical connections at the fuse box, fan motor, fan sensor switch, and sanded the ground for good grounding. Everything is in working order.

Now, im kind of stumped as to what is next. Anyone have a clue to what i might be missing? I am looking over the Honda manual right now and am coming up with nothing.





-nate

[jrivas]

have you ran through all the wiring?? any frayed wiring?? just an idea

[cbr1kfireblade]

have you found a relay anywhere?

did you replace the sensor mounted on the thermostat housing?

[Stu494]

Ahh... I know what your problem is, but as to where to fix it... but just to make sure, this fix is for a SP1

On the left side Rad there is a sensor on the front. This provides a earth for the fan relay, so when the water temp hits a certain temp, it will trip the swich in the sensor, earth out through the rad, and turn your fan on. This may be where it is failing; to check, remove the wire from the sensor, and earth it out with just the ignition on (bike does not need to be running). If the fan comes on, its the sensor. You could replace it for a stocker, or buy an aftermarket one. There are plenty of modern vehicles that have the same pitch thread and body length. Some have two wires, but dont worry about that.

If you deciede to purchase an aftermarket sensor, you have the oportunity to buy a different temp range. I live in Australia, where it gets warm, and decieded to get a sensor that tripped at 95 deg (203). it has two wires; one of them needs to go to the exsisting wire, and the other has to go to a ground for it to work (you can add another wire to this, that goes to a switch to turn your fan on manually). Anyway, on a 30 (86) deg day, stop start city traffic, the temp never gets above 87 (188), and sits on 78 (172)to 80 (176) at speeds. I havent done anything to my fan or thermostat (both are factory), and I run Penrite SYN coolant (its glycol free).

If it isnt the sensor, you next need to look at replacing the relay. I would go genuine here, but cant give you the costs.

Hope all this helps. I am looking at having a reversed pitch fan put on my bike soon, so hopefully i will get even more stable running temps. Will post and let you all know how it goes

[ShtNgiT]

Originally Posted by jrivas

have you ran through all the wiring?? any frayed wiring?? just an idea

thats correct i did.

now, i did come up with a solution last night before bedtime and it worked.

Instead of the ground going to the frame like initially thought, it was supposed to connect to the upper fan mount at the radiator (DOH)

[jrivas]

Originally Posted by ShtNgiT

thats correct i did.

now, i did come up with a solution last night before bedtime and it worked.

Instead of the ground going to the frame like initially thought, it was supposed to connect to the upper fan mount at the radiator (DOH)

we are getting somewhere sht!!!

[zerogara]

There is a thread about this thermostat switch issue on SP1s that is not too old. Just look down the list about a major thread for cooling and you'll find all you need.
The SP1 doesn't have a relay, the switch on the radiator turns the fan on directly (simple DC current going through). So do the test as STU954 says.
If it is the switch (on at 220, off at 210) there is a switch off of a car (part number listed on that other thread) that it is easily replaced.

[cbr1kfireblade]

he got it working

[jrivas]