2001? Yzf 426 stroked complete resto

How is the bike? Any progress made?

Well guys another riding season is upon us and I have decided to give this motor another shot at figuring out that tapping noise.The bike has sat in storage since last year when I gave up on the project temporarily.pulled the valve cover today and started checking everything over with a fresh mind. One of my intake valves has excessive clearance (can't remember what it was off hand will post specs tomorrow when I grab the paper I wrote them on from work) and the shim is stuck in the valve. Just read a thread in which grayracer layed out a method of tapping on the top of the valve lightly with a magnet handy.I will be trying that tomorrow. Will keep you guys posted on progress.

Well I have an update for you guys. Dropped the bike off at the local shop.they ran the bike and blew a piston.Apparently one of the intake valves was hitting the piston but I don't see any evidence of that on the valve just on the piston. I have a spare used head that I will be shipping to mongoose cylinder works on Monday to have rebuilt.amazingly the crank and cylinder came out completely unscathed. I cannot believe a valve was causing all that noise and yet the bike would start first kick.Heres some pics let me know what you guys think.ImageUploadedByThumper Talk1460779226.711330.jpgImageUploadedByThumper Talk1460779239.246788.jpg

What exactly happened to the piston (other than the missing chunk of ring land)?  It looks to me as if it's been hitting the head squish area for a while.  If I were you, I'd double check the rod bearing clearance.


Solvent test the valves.  If any leak, pull them and chuck the stems in a lathe or even a drill and check them for being bent. 

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