2002 YZ426F kickstarter wont budge

2 replies to this topic
  • tward626

Posted December 09, 2013 - 04:43 PM


hey guys new here to thumpertalk and Im lost and confused with a issue i have on my 02 yz426f. i was out riding and went through a small pond not very deep (till i hit the hidden whoop) crashed and the bike and i fell into the water. the water was probably about 45* degrees. when i got the bike out. (only submerged for about 20sec if that). i tried to start it and the kickstarter wont move. there is no water in the oil but there was some in the spark plug well. i figured water was just in there and water wont compress and that was my issue. I know my way around a car/truck engine and i am mechanically inclined but when it comes to bikes im lost.  :confused:

i will post pictures when i get a chance to.



Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • NitrousR1

Posted December 09, 2013 - 04:57 PM


Do not start it! Don't attempt to move the kick starter. If the valves arnt bent allready, they could bend upon start up. Personally I'd just start tearing it down.
I'd pull the head. Remove the valves, verify they arnt bent or replace them and get the seats cut. Inspect the seats for damage from bent valves. Inspect/replace the piston.
Check the connecting rod to see if its bent. Flush out the crankcase multiple times.
Anyway you cut it, it needs disassembled and rebuilt. Keep in mind it may be costly depending on what's damaged. It could be anywhere from $500-1500 & upwards if you do it yourself. Could be close to what the bikes worth. Significantly more If you take it to a shop. Download the service manual and print out the engine section.

  • grayracer513

Posted December 10, 2013 - 09:03 AM


If the engine was hydro-locked (water in the cylinder), pulling the compression release would have allowed it to turn over.  If that didn't doit, there's some other condition at work. 


Unless the engine slipped time during the crash (which is possible if the timing chain is in bad condition), there is no reason to think the valves would be bent, so I would not go ripping the head off until you figure out what's up.  If you can't turn the engine over (gently) with the compression release pulled, remove the cam cover and check the timing.  Correct it if it's off, and replace the chain, then go from there.  If the valves are timed right, they won't suffer any further damage from cranking the engine even if they're bent, but if they are, there won't be any compression.  


If it is or was just water in the cylinder, you should be able to clear it by cranking the engine with the compression release pulled, or if that's been removed, with the spark plug out of the head.  If the whole bike was under water, it probably entered through the exhaust or intake (the carb will have water in it,BTW. You need to address that).  If you get it cleared and the engine turns over in a reasonably normal manner, try the plug back in it and see if it has compression.  If so, you have a decision to make: if the water was dirty, there is dirt in the top end.  You can get away with that if the water was fairly clear, but you're taking a chance if it was muddy.  Might want to go ahead and remove the top end just to clean it up at that point.

Related Content


Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride

Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies

James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

Megabomb Fitment by 288yz450

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply

Yamaha YZ450F 2017 by Chris.GVS

Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.