1997 RF900R Cooling Fan Issue

[JimmyB21]

Hi,

I'm new on this forum. My '97 RF900R has an issue. I know the full history of this bike since new (my friend's dad, then my friend, then me).

A few months ago, we had some reasonably temperate weather so we got the bikes out. Warmed up the bikes a while, as there was still a nip in the air. As we pulled out of the driveway, my bike quit. Rolled back down the driveway, checked it out, and the "ignition" fuse was blown. Replaced it, bike ran fine all day, no further issue so I shrugged it off.

Fast forward to last weekend. Much warmer out (in the 80's I'd say). Took the bikes out, were doing fine until we came out of backroads to a town with lots of stoplights. My temp went up, but not dangerously, and I didn't notice the fan come on. Bike died at a light. Pulled over to the side, checked the fuse, sure enough it was blown. Replaced it, got another 50 feet and it blew. Let the bike cool off, tried another fuse, and hobbled the bike home keeping it moving and cool the whole way.

Checked it out at home and one blade of the cooling fan was melted, and the fan was stuck in place. Now I know why the fuse blew. The fan tried to kick on, and it couldn't because the fan was stuck, but it was just dumping current through the fuse to try and start the fan. I took the fan out, leaving it connected electrically, and shorted the fan switch leads with the key on and kill switch on (and a new fuse) and the fan started up and ran. Could the coolant fan switch be bad? Is there a history of this part failing on the bike? I can't see the fan melting, unless it wasn't spinning (because then it is sitting right next to the exhaust manifold), but the only cause I can see for it not spinning is a) it melted already and coouldn't spin (a chicken or egg argument) or b) the temperature switch was flaky.

I ordered a new fan and coolant switch, and I'll replace them, but if anyone knows anymore about this problem, please reply. Sorry for the long one, any insights would be great.

-Jim

[gsxrjeffro]

GO ON http://autos.groups.yahoo.com/group/suzukirfclub/ YOU WILL FIND YOUR ANSWER
-JEFFRO

[JimmyB21]

I'll subscribe to that list and post this. Thanks for the link.

I replaced the fan, the fan coolant temperature switch, and drained and refilled the coolant. Ran the bike with the fairing off so that it would heat up and I could top off the coolant. Let the fan come on, then shut off. The fan had melted again when it stopped and I took a look at it. Either the exhaust is too hot, or the fan is too close to the header.

Any ideas?

-Jim

[JimmyB21]

Just to preserve the information. I found out on the RF list mentioned above that this seems to be a common issue. Several people replied that they had experienced melted fans.

The most common solution is to replace the stock plastic fan blades with aluminum ones that are available from Muzzys.com or SchnitzRacing.com (same product, from Muzzys). It's about $35 + shipping. They are available for several different bikes, in case this is seen on any other models.

I just wish I hadn't bought a set of replacement stock blades for $40 just to have them melt on the first heat cycle. Oh well, live and learn.

-Jim