2008 XR650L Top End Issues

Hello all,


I have a 2008 XR650L that has less the 10,000 miles on it.  I use the stock size front and rear sprockets for my street setup, and put on a 14 tooth front and a 47 tooth for the rear for my off road set up.  A few months ago I took it on an 800 mile or so ride with some friends and about 400 miles in the top end was making a pretty good racket and it felt like there was a vibration through a certain RPM range regardless of the gear I was in.  We stopped for dinner and I gave the bike about an hour and a half break.  When I started it up the bike ran smooth for about 5 minutes until the bike was nice and warm again and then the noise and vibration were back.  A few times during the ride I got the bike up to 90 - 95 MPH but mostly we cruised around 75 MPH.  I did have to keep it at this speed and RPM (no tac) for quite some distances at times.



I drove it home the way it was and made it home, but the bike feels to have less power.  I can still pull wheelies and climb hills like i want to when I dirt ride, but if I fully twist the throttle the bike acts like its flooding out or going to die.  When I am going at 60+ down the road and WOT it will miss sometimes.  When the bike is warm from riding for more than 30 minutes it almost sounds like my exhaust leaks from the gaskets on the head.  I have tried to tighten them down more, but they aren’t loose. 



I am not burning/using any oil.  The bike likes to start and run like normal.  My signature has everything that I've modded or done.  I could sure use some advice or direction on what to check.  My rough plan is to take the head off and look at cam and valves and go from there

Edited by WarHammer0106

Crikey you guys are hard on your bikes..95mph at 14/47,,the thing must have been ready to explode,,even 75 for long periods with that gearing would freak me out. Road gearing is 16/39..I even find that not tall enough for extended higher speed running on my 600.,could do with one more gear as far as I'm concerned.  I don't know what's up with the bike,,maybe it;s got a headgasket problem but as opposed to blowing out the side it's blowing into the camchain area..Apart from that,,dunno,,maybe some carb/jet blockage

Edited by Horri

The 14/47 is my dirt gearing.  I was full road set up with Distanza rubber front and back with stock gearing, or at least how i got it.  I was 15/45 for this trip.  I can hit 70 in 3rd gear with this gearing.  Crank feels like it wants to fly out of the bike...but I can do it.  I appreciate the advice Horri, and I am not discarding your experiance, but head gasket issue doesnt "feel" right.  Wouldnt a head gasket issue become less with the heating and expanding of the motor?  This gets worse as it gets hot.  I am worried that I starved my top end of oil after an oil change.  I changed my oil the day before we left on this 800 mile ride.  I am worried that i have the dreaded XR650 seating issue, but am looking for ideas and other experiances to help me along. 


I will be pulling the top end here in a couple weeks.

I'm just guessing..Suppose if the gasket was faulty as you/I say it may close up with heating..Have a look at things when you get her apart,,Too hard to tell what may be up without a look inside. I guess someone else may chime in with another idea..,70 in third,,not bad,,,I can hit 50 in first..maybe..Joking,,unsure on that.

Edited by Horri

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