426 wouldn't start


3 replies to this topic
  • jallen426

Posted August 08, 2012 - 05:11 PM

#1

Hey guys, first post, but I've been a long time lurker.
I have a 2000 426. I've been riding it will no issues for about a year now. The other day I pulled it out of my garage for an oil change and filter clean. After cleaning the filter I wanted to warm it up before an oil change. After kicking it over for 20 min, which was odd because it usually starts very easy, it still didn't start. I pulled the plug and checked for spark. I tried starting it again and on the first kick, with the decompression lever pulled in, it back fired. After that it seemed to lose compression and I couldn't find top dead center. Now when I kick it over it sounds like compression is coming through the carb. The spark plug was a tan color and very dry. A guy told me I probably broke a valve and to pull the head....so I did, and everything looked good. The timing chain, cams, valves and top of the piston all looked good to me. I'm really not sure where to go from here and was hoping to get some advice and direction as to where to look next. The last time I rode it was a 30 mile single track ride on a very hot day. I don't think I overheated it but I guess its possible. I shut the bike down that day and it didnt seem to run funny or make any odd noises. Thanks for any help.

  • corndog

Posted August 08, 2012 - 09:11 PM

#2

Sorry it's under crummy circumstances, but welcome!

I just bought an '01 426 and put the slide plate in upside down after cleaning the carb, which result in me trying to start the bike for like an hour like an idiot. I tried pushing starting it and held the decompression lever in because I thought it may have been flooded and I was trying to clear the cylinder. Well, when I put it back on the stand, it had no compression. I thought, oh great, I bent the exhaust valve by pushing it while I had the decompression lever in. After a few minutes, it returned to normal and the bike runs great. The only thing I can think is, maybe something stuck open in the decompression cable/actuator/whatever. Perhaps yours suffered the same oddity?

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  • grayracer513

Posted August 09, 2012 - 07:55 AM

#3

Check the cam timing and correct it as necessary, then do a leak down test if the compression has not returned.

  • jallen426

Posted August 09, 2012 - 04:41 PM

#4

Thanks for the responses guys. Will I be able to get a good reading from a leak down test if the engine isnt installed and able to be ran? Because right now its sitting on the bench, out of the bike and in several pieces. Is there anything I should look for before I reassemble it?

thanks again





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