250-500cc WR 300 2012 suddenly dies.

Yesterday we where out riding, and at some places there where some quite deep waterholes. Bike ran flawless almost all day, but at the end after we went through a deep waterhole it suddenly statred to cut out and die. Directly afterwards it starts again, runs for a short while and dies again. if io lay on higher revs it runs but i can feel that it wants to cut out in between. I have drained the carb (keihin) and i don't see water in the plug cap. Does anyone have any ideas about what it could be? Any help is appreciated!

Johnny

check the wiring loom that comes from the coil and goes to stator....had a similar problem few weeks back and the wiring loom was rubbing on a part of frame near coil and rubbed right through exposing the wires.

Ok, thanks! I'll check that and get back!

I just checked and it looked good all the way from the ignition module down to the stator. The bike has about 20 hours running time, fuelflow is good through the carb, so i don't believe in any fuel delivery problems. It dies too suddenly for that too. I removed the stator cover and there was a small amount of condensation, but not much to worry about.

My 144 was doing that I had water in the cdi plug

Well, i already checked that one on the underside of the CDI. Totally dry:=(. I guess you mean the yellow one, right?) It starts perfect after a short while, but right after it died i can kick it and it's totally dead. The fuelbowl is full of fuel, the float is perfect, jets are cleaned, plug is changed.

If it was the water crossing and you happened to get some water into the carb maybe some got into the crankcase? You drained the carb but there still might be a little water in the bottom end getting pulled up into the cylinder.

Well, there was some deep water crossings for sure, but shouldn't it have disappeared by now after about 15 minutes riding?Plug doesn't look wet when i checked at least.

How deep was the water? Did it submerge the engine or was it more of a fast splash through the crossing? If its electrical is seems like it should be OK once things dry out.

Water in the crankcase might be under a layer of oil which would keep it from evaporating when sitting. Might take more than 15 minutes to get it hot enough to dry it out, depending on how much water would be in there. I have a temp gauge on my 2011 300 and it only gets above 200 degrees when I'm climbing steep and slow stuff or using the clutch a lot. With medium RPM and air going through the radiators its running right around 160-180 degrees F. Not hot enough to boil water.

Be sure to tell us what you find. I haven't ridden through a lot of water yet but I'm sure my day is coming.

Ok, now i have found something. When i hit the handbrake or footbrake, the bike dies. Any ideas?

Mines been doing the same all year, right from day one. Bought it second hand so don't know full history. I'm sick of it. Only managed 20 minuites of a 3 hour race today before she blubered and died. Only finished 2 out of 8 events this year. I've checked all of the above and more, I ve found damp electrical plugs, dried them out but this keeps coming back. I think now my coil or stator is at fault. So, i have no new info but please keep us informed on how you go.

I found my problem! The taillight. I was checking the wiring diagram and saw that both the handbrake switch and footbrake switch of course goes to the taillight. I took my lamp off and cleaned the contacts and now it runs perfectly, but the brakelight doesn't work. It can maybe also be the lamp itself, but something solved my problem. Those cables also goes up to the handlebar switches. The yellow cable for the lights seems to go from the stator plate, so i guess that when i hit the brake pedals there was a shortcut in some way. What do i know? I know nothing about electrics, but now it runs. Crazy. We'll see for how long!

Man, there should be a fuse on that stuff! Yikes. C'mon Husqvarna...

I'm going to check my bike for a fuse on the lights, and add one if there isn't one already. Scary!

Good work!

I had the same issue with my 165 straight out of the box. Had me fooled because it died braking into corners (chopping the throttle). Turned out to be the pilot jet had some crap in it. Runs awesome now.

That is Incredible, thanks for making this find and sharing it with us...as soon I get my wr300 In gonna check out everything !!!
Cheers Great Work Thanks !