trent_181 said:
we do a lot of slow riding but i replaced the cap nand we have gone through every possibiltiy of what could be making it over heat and we can not figure it out, the only thing i havnt done is replace the thermostat, but i pulled the thermostatout and it opened up with boilng water but not with 50 degree water
Not a bad Idea, however you can't just remove the thermostat itself, you will have to eliminate all of the hosing and run it straight. By just removing the thermostat you have an open loop in the cooling system that will allow coolant to just recirculate without passing through the radiator. If you want to remove the the thermostat you will need to do it like the FS, and FC models of that year, pages 74 & 75 of the spare parts manuals.
However, I don't think that is your problem. Your problem is not enough air flow over the radiator, and, possibly low engine revs in your tight riding.
You can also drill holes in all of the radiator louvers to allow more air flow to go straight into the radiator
Try keeping the revs up a bit higher, E.G. ride in a lower gear. This serves two purposes, it circulates the coolant faster through the loop, and requires the motor to make less power thus generating less heat. This technique worked pretty well for me on my 04 550.
However, in the end, I put Evans NPG-R coolant in it to eliminate the boil overs all together. The NPG-R is going away as it was not rated for below freezing temps and has been replaced by a new fluid that is rated for below freezing temps, I believe it is called power sports or something. Go to their web site and it will be easy to find. As I said before this will be the easiest way for you to eliminate boil overs. The Evans will make the motor run about 20 degrees F hotter as it does not exchange heat as well. HOWEVER, the coolant stays in the motor, and you will not have boil overs. You just have to be smart about it though, you can't sit still and abuse your clutch forever trying to get out of a tight spot. For me, it worked out great when running the National Hare and Hound series..........You'd come to a big uphill, or tight section that would normally cause a boil over, but, with the Evans it would not, and in a while you'd be moving again and the motor would cool off since all the coolant was still in the cooling system, as opposed to it puking out an unknown amount, and then having to decide whether to ride on, or stop during the race and top off.
In my case when I saw a guy parting out an 06 bike I bought his tank so I could install a stock radiator fan kit. Your year bike does not come with a bung in the radiator for the thermo switch, and neither did mine. Again, In my case a guy was parting out an 07 bike and I bought his radiator which did have a bung for the thermo switch. However, you can get a local radiator shop to install a bung for the thermo switch, or, they make in line thermo switch wells that you just cut into the bottom hose of the radiator. If you go this route, make sure you get the 100C switch and not the 85C switch, or the fan will run all the time. And when that happens, the fan will take all the power that is converted to DC, and that means that your battery will eventually loose its charge, and you will be kick starting your bike as the stock stator rectifier/regulator only puts out 25 Watts DC and the other 90 Watts is put out as AC voltage to run the lighting. This was a complaint among fan users, and that is why I suggest the 100C switch, as that was the solution for a lot of these folks.
In my case, I had my stator rewound by UHE member SPARKS, and installed a trail tech universal reg/rectifier, and made my bike all DC voltage. Plenty of power then to run the fan continuously, charge the battery, and run all the lighting and then some.
Speaking of which, do you have the closed course jetting in it, or the EPA green jetting?
You should be running a 40 pilot, and OBDVR needle 5th from the top at the very least, and set the fuel screw according to the manual. The stock EPA green jetting makes the bike run a lot hotter.
One last point, do you bleed the cooling system each time you ride the bike? There is a small 8mm head bolt right next to the spark plug. It is pretty critical that you bleed coolant from this screw as there is an air bubble that forms in the head, and if there is air where there is supposed to be coolant, then its going to get hot. When the bike is cold, simply take off the radiator cap and loosen this screw until coolant with no bubbles is coming out. You will be surprised at how much air is trapped in there.
Hope this helps,
Dale
