Mechanical Nightmares!

[Süsser Tod]

So I was riding home and traffic was not so bad, until I was close to home, it was a mess. Lots of stop and go, but not for very long as I was REALLY close to home. Like three blocks from home I hear the fan turn on, but the sound was not normal, as if something was stuck in the fan and then it quieted down... Meh...

One block from home, I smell something... coolant! I look down and I see coolant spewing from somewhere close to the radiator. Damn! I get home and as I'm parking the bike I can see steam coming off the front of the bike, so it's clear something is really wrong.

A few weeks ago I suspected the radiator cap was bad, as a couple hoses leaked a few drops of coolant, as if they had come lose. I tightened the first one, but when the second one leaked I suspected there was a bit more pressure than it should on the system. So I cleaned it up, almost screwed up the radiator cap in the process, but I managed not to and everything had been fine since then.

Cooling system trouble again? FFS! I understand why people love aircooled bikes for trips to nowhere.

Where to begin? Parked the bike, started up the engine and the coolant boiled, it started spewing coolang big time! But, the fan didn't turn on... Neither did the temperature warning light...

It must be the radiator cap that is unable to hold enough pressure for the coolant to heat up and the fan to turn on. I was so sure I needed a new radiator cap that I made some calls, and found out that Yamaha de Mexico doesn't have one in stock, I would have to order it and it will take a month...

The bike was going to be out of comission for one month! Well, there was nothing to lose by trying to fix the cap again, so I removed the tupperware covering it and took a look at it... Looks fine. Nothing wrong with the damn thing that I could tell, but I don't have the tools to pressure test it. Refilled the radiator, put the cap back on and start the bike. The engine was hot, I squeezed the hose that goes from the pump to the radiator with all my might, and not a single drop came out the radiator cap to the reservoir... After all, there is a chance the radiator cap might be fine as it was holding some pressure.

So, what else could it be? The fan. First I thought that the weird sound of the fan was due to the coolant hitting the blades, and that it had quieted down after it had evaporated. What could keep the fan from spinning? Fuses! Get the fuse out and it's fine, I even used a multimeter to test it. Next thing, it's either the relay or... The fan itself...

By this time I had already mopped the garage floor once, I wasn't really eager to start up the engine and have the bike puke coolant again. The relay would have to wait, the fan was already accessible as the tupperware had came off.

It wasn't spinning freely. It seemed like if something had got stuck in the blades, but there was nothing I could see. So I spinned it clockwise a few times, then counterclockwise and repeat. It seemed to work, not so stuck anymore, but it still felt as if something was grinding insie it, but it was moving. Time for another test, I should have got a bucket, but I didn't. Started the engine and waited...

(I like living dangerously... or I failed miserably at moping the floor the first time, and I knew I had to do it again as it was slippery)

And the fan turned on, completed it's cycle and no coolant was spewed!

Remove the fan, clean it up as best as I could, but the thing is impossible to take apart. Flushed it with WD-40 and isopropilic alcohol as whatever seemed to have got stuck must had been in between the impeller and the motor, and after flushing it with WD-40, cleaning it, and then flushing it with alcohol to remove the remains of the WD-40, it wasn't grinding anymore! Reinstalled it, refilled the overflow tank and waited...

Again, everything works as expected. My little girl is not sick anymore!


Nightmare? Yes! The XT660R was never available in the USA, therefore I can't order parts from the USA as I do with some of my other bikes (XJR1300 is the same trouble as the XT). Everything has to come from Europe, Australia... Or I can wait for Yamaha de Mexico to get me the part in no less than 1 month, which once turned into a 6 month wait (I swear). Wheter it had been a bad radiator cap or a fan, the bike would have been out of comission for no less than a month.

[Builtgypsy]

Good to know it was an easy fix after all the troubleshooting! What a thought, that poor thing out of commission, you would have had to take another one of your half dozen bikes out of the stable instead.

[Alawicious]

Glad it worked out Suss.

As I was reading it, I was thinking water pump

[OldSchlPunk]

I was thinking head gasket. Damn glad it wasn't that!

[LaurenOE]

Sometimes air gets trapped and cavitates. Glad it worked out.

[Süsser Tod]

We'll see if she behaves nicely today on my commute. Waterpump and headgasket hadn't crossed my mind... Ugh...

[Süsser Tod]

She behaved nicely, although I'm a bit paranoid and everything reeked of coolant, LOL!

As I was showering I remembered one of my dreams, I did dream of mechanical stuff! When I was done troubleshooting the cooling system I did a quick check on everything, bearings, fluids, some nuts/bolts, and... The chain. A couple months ago I installed a cheap "Factory Spec" on it when the OEM chain had too many stiff links. There is sense to the madness, as the sprockets for the XT are quite expensive, unlike sprockets for more common bikes that you almost get for free with the purchase of a new chain, the cheap chain was just meant to last enough to get those sprockets worn...

Truth be told, I'm not entirely comfortable with that chain. It works fine, hasn't stretched more than the OEM chain did, but I can't get myself to trust it like I did with the OEM chain.

In my dream, I was looking at the chain and saw it was too loose. I was spinning the wheel to check the chain, just like I had done it in the afternoon, and it was WAY too lose, I could remove it from the rear sprocket! I kept spinning the wheel and it jumped out the front sprocket! I put it back on and kept spinning the wheel (it is a dream, why should it make sense, right?) and noticed that part of the chain was twisted backwards! I tried to twist it back to it's regular position and the most twisted link was... broken, and just held on by pieces of rubber that at first I thought were the o-rings, then I realized the o-rings just go around the pins, and it "morphed" into something that looked like a link made out of rubber...

At that point I realized it was just a dream. LOL!

[Alawicious]

Dreams can be so wierd sometimes

[bumblebee]

Originally Posted by Süsser Tod

We'll see if she behaves nicely today on my commute. Waterpump and headgasket hadn't crossed my mind... Ugh...

Thermostat was my first guess from what you were describing

[Alawicious]

That crossed my mind as well. Had the issue been with a car, it would have been my first check