Bad start for a new '05 450 EXC

I got this bike just a week ago and had the worst bad luck you can possibly imagine with it.

This happened just after my first hour of running the bike for its break in period. I was in a nice sandy when I plunged into a pretty deep water hole. All of a sudden the engine stalls and I get stuck right in the middle of it, knee deep in the mud. I hit the trusty starter button and hear flushy sounds down bellow. Checked it out, it was horrible... Water was pourring out of the engine! Unbelievable...

I was lucky enough to come accross a nice guy on a quad who towed me back home. Then I got a closer observation of the problem.

The clutch cover gasket poped out of place in the bottom part. All the oil was quickly pumped out and water sucked in. Pretty much the worst case scenario for an engine.

I took the bike back to the dealer. They checked and cleaned the engine, found no traces of wear or damage to any parts. Right when I got it back I rand the engine for a few minutes and had them change the oil again because it turned white right away.

All this happend because the breather was blocked. On the EXC the breather is plugged right before the carb in order to recycle oil vapors. The piece of plastic on which the hose is plugged was for another model and didn't have a hole on it. Pretty dumb assembly error I'd say.

Now, a week later, I ran about 3 hours on it. The engine looks fine to my knowledge, has no noticeable leaks, plenty of compression and doesn't smoke at all.

One thing however, my hydrolic clutch leaked, probly in the engine since I saw no traces of oil outside.

First guess is, the slave cylinder was stressed by the high pressure variation of the engine while the breather was blocked. This may have altered the seal.

Other possibility, there's still crap in my oil which is totaly ruining my engine ...

Now I'm wondering what's next? anybody had similar experience? I could use some hints on what to check. My dealer isn't that bad, but he doesn't care enough to realy go through everything...

That is getting of to a poor start. Where you there when they removed the clutch cover? If there was sand/grit present I think the engine should come apart, if it was just water no big deal although it tempting to ask for an extended warrnety (I did this with a new car a while back and they bought the car back).

The carb bell must have been for an SX. Next question is, do you have an SX carb?? If so it will not have a two wire electric piece on the top left corner know as the TPS (Throttle Position Sensor). The EXC uses this to calm the engine and maintian traction in mud.

Your correct in guessing that the crankcase pressure pulsing blew out the gasket and probubly nuked the slave clyinder. The good news is the slave is cheap & easy to rebuild but it should be under warrenty

I didn't see them work on the bike, but the water wasn't too dirty. I probly should run the bike as much as I can till fall and then check for compression and unusual wear...

Went to the dealer this morning for the clutch issue. He doesn't realy believe the pressure may have damaged the cylinder. We're too late anyways to order and get the piece before the coming weekend, but if it leaks again he'll replace everything needed free of charge.

Wish I'd known about the baby oil sooner, missed a great riding day while searching for SAE 10 biodegradable mineral oil :-P

I'm not sure about the TPS, will have to check this weekend...

I removed the breather hose from the carb and connected a fuel filter to it and ran it down with the carb vent hoses. I hope this is an ok thing to do. If anybody knows different please speak up. :excuseme:

Air bell on the carb would be better, that thing sucks and blows both in & out everytime the piston goes up and down so when run down there it can suck water into the engine

Whats this about baby oil? Is it a suitable replacement for the cluch fluid? Tell me mopre please.

Whats this about baby oil? Is it a suitable replacement for the cluch fluid? Tell me mopre please.

Baby oil is fine for clutch oil. Look on the bottle and make sure it's 100% mineral oil.

I believe 2006 was the first year with the TPS on the 450 exc wasn't it?

I have a 2005 540 SXS and a 2006 525 EXC. The 540 has an oil breather that IS NOT attached to the carb. It also got me pretty damn worried when i found out. I used the SXS once on a trail ride which involved shallow water crossings ( the footpegs would be submerged with me on the bike )i also thought of installing a fuel filter or an RC car foam air filter until i consulted our dealer down here. The SXS' breather, according to the dealer, has a PULSATING pressure, meaning it does not have the capacity to suck in the water all the way through since the pulse rate is too fast... by the time water or dust starts to get sucked in.... pressure again blows it out. Then, after reading this forum.... i called him again with regards to this problem with a 450exc. He said that the bike must have had a leak somewhere rather than blaming the breather for fouling things up. Maybe your clutch cover had a slight opening caused by an incorrectly fitted gasket. Sheesh.... i wouldnt know

Or motor oil, or ATF, or suspension oil, just about anything but brake fluid.

On your 540 when the piston goes down 540cc of air under the piston is displaced, must flow out that hose or be compressed. When the piston goes up 540cc of air must flow back in. To help visualize this a pint is abt 450cc. At running speed it is pulsing in and out so fastminimul water can be sucked in. Now ask yourself, if you stall in the creek, and the piston is down, and you push the starter and the piston comes up causing over a pint of suction with that hose under water what is inside of your engine? Anwer is a pint of dirty water!

The SXS was intended for track use only (and I am very criticle of KTM for routing the SX hoses as they do).

The EXC was intended for slopping around it the streams and they properly ran the hose to the cleanest dryest sorce of air on the bike.

IF your going to take that SXS into the woods route the vent hose like the EXC which involves drilling the hole into the carb bell

JCOORMI

All RFS models except SX & SMR have the TPS

On your 540 when the piston goes down 540cc of air under the piston is displaced, must flow out that hose or be compressed. When the piston goes up 540cc of air must flow back in. To help visualize this a pint is abt 450cc. At running speed it is pulsing in and out so fastminimul water can be sucked in. Now ask yourself, if you stall in the creek, and the piston is down, and you push the starter and the piston comes up causing over a pint of suction with that hose under water what is inside of your engine? Anwer is a pint of dirty water!

The SXS was intended for track use only (and I am very criticle of KTM for routing the SX hoses as they do).

The EXC was intended for slopping around it the streams and they properly ran the hose to the cleanest dryest sorce of air on the bike.

IF your going to take that SXS into the woods route the vent hose like the EXC which involves drilling the hole into the carb bell

Now that's the explanation i was looking for. With regards to stalling.... my dealer could not give me an answer.... or i guess i got an answer i could not

"quite" comprehend :ride::ride: i guess this'll make me realize that with my sxs, i should/shouldnt:

1. (Shouldnt)Cross Streams over 12 inches deep

2. If deeper than 12 inches... push it across or find another way around

3. (SHoudnt) Start the bike if i see that the water is a tad too close to the breather hose

4. (Should) Use the EXC for trails and keep the SXS for track :ride:

Howdy!

After a couple of weeks riding, things aren't so bad. I added oil to the hydrolic clutch, bled it properly and it doesn't seem to have leaked since. I find this a bit strange, but as always, if it ain't broken, don't fix it.

The carb is fine too, it does have the TSP so I guess they didn't mix this up at assembly too!

Btw, did I mention I like this bike? :thumbsup: Woot! I spent a few days riding in the sand pits for the first time in my life, it was incredible! Hard to describe the feeling, most of you riders must know how it is, standing in the bottom of a pit, gazing at a 60 ft tall hill, overthinking how you're gonna do it ... Then pull the throttle, shift, shift, hit the bottom, hold on to the bar as the bike pulls you up, the engine's screams reverbs on distant hills ... you then shortly leave the ground, thinking, Holly shiiit! and after a somewhat awkward landing, you just want to do that again, and again...

Aaww this is living!!

anyway... thanks for the replies! I know where to come for info now!

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