Re-doing the top-ends of my XL 650L's

I've got a 2005 XR 650L. I just bought a new (2007) just a few days ago.

I have already ordered 2 sets of White Bros pipes and mufflers. I'm starting out with the older bike first. The motor is in need of conditioning anyways...I'm pretty sure the pistons rings are going bad. I'm getting the head(s) ported and polished. I'll be doing the rejetting too. Been thinking about installing a higher compression piston and even a bigger cam.

Been talking to one of the perf reps here at a local Bike Dealer and he sounded pretty knowlegeable about 650L's.

I've just about got all the tech details figured out for myself. One that I am kinda ignorant about is the gaskets, namely will OEM gaskets be adequate enought to withstand the higher compression forces.

If anyone would care to share their triumphs and failures with 650L' (even R's), especially in dealing with top-end re-builds/mods/upgrades....whatever, please let me know.


If you going thru all that and getting the head proted and polished you should definitely do the Hi Comp piston at least, maybe the cam too if you wanna. If its not a money issue might as well do it all. Should be a warrior with all that done

I went with the big bore kit, 102.4mm and 10.25 CR. Fred at can get you the gaskets if you want the big bore. I also use a cam from megacycle, hardened rockers and a mikuni.

I don't think you need anything special gasket wise unless you go bigger bore. 10.5 to 1 is probably as high as you want to go on pump premium and air cooled.

definately use OEM gaskets.

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