yz 426 rebuild cost???

I have a '00 yz 426--I recently had valves adjusted and runs great--note It has been ridden hard for 2 years. Last time out bike started making a "ratteling" sound-much more pronounced as revs increase--almost like a loose skid plate,pipe etc. I checked all things that could come loose and so far all is tight. The noise seems to be comming from right side of engine case.It has not lost any power even with this ratteling. It is loud enough to hear while racing(I race super-moto).Clutch actuation makes no difference.

Is it time to have everything dis-assembled checked and rebuilt? If so what cost is to be expected?

Sidebar--noise was less noticable a month ago and I removed cluthcover and clutch assembly--all appeared ok? :thumbsup:

Thanks for looking and any advice you may have is appreciated.

Just rebuilt the top end in mine and truthfully it did not get any quiter. A wiseco piston makes a little bit more noise. I ran into the the same problem with about 4 or 5 hours of ride time on my fresh top end and finally after a week of troubleshooting realized my timing chain was shot. Replaced timing chain and all is good to go. Cost me 150 for wiseco top end kit, 32 dollars for timing chain and about 50 bucks for fresh oil, all new gaskets on case covers, clutch cover gasket, timing chain tensioner gasket, new antifreeze, and some random nuts and bolts. Bike is like brand new and rips! If you rebuild top end replace timing chain regardless......cheap way of insuring nothing goes wrong!

Just rebuilt the top end in mine and truthfully it did not get any quiter. A wiseco piston makes a little bit more noise. I ran into the the same problem with about 4 or 5 hours of ride time on my fresh top end and finally after a week of troubleshooting realized my timing chain was shot. Replaced timing chain and all is good to go. Cost me 150 for wiseco top end kit, 32 dollars for timing chain and about 50 bucks for fresh oil, all new gaskets on case covers, clutch cover gasket, timing chain tensioner gasket, new antifreeze, and some random nuts and bolts. Bike is like brand new and rips! If you rebuild top end replace timing chain regardless......cheap way of insuring nothing goes wrong!

Just rebuilt the top end in mine and truthfully it did not get any quiter. A wiseco piston makes a little bit more noise. I ran into the the same problem with about 4 or 5 hours of ride time on my fresh top end and finally after a week of troubleshooting realized my timing chain was shot. Replaced timing chain and all is good to go. Cost me 150 for wiseco top end kit, 32 dollars for timing chain and about 50 bucks for fresh oil, all new gaskets on case covers, clutch cover gasket, timing chain tensioner gasket, new antifreeze, and some random nuts and bolts. Bike is like brand new and rips! If you rebuild top end replace timing chain regardless......cheap way of insuring nothing goes wrong!

Sounds more like a clutch noise than something in the top end..... but I dont know a whole lot about engines.

If your clutch looks good...Its not a clutch problem...youll know if it is. It will be something obvious. The sound is deciving. it sounds like it is coming from a certain place like mine but it is somewhere else

I wish I had better advice, but maybe you could try holding a screwdriver (handle end) to your ear and the blade end to different parts of the motor (as a stethoscope). Maybe you could get a better idea of where/what the noise is..

Anyway, good luck on that.

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