XR0650L- 720cc Big bore Kit?

I have been doing some research on big bore kits for the "L" and I see the offering from LA Sleeve for the 720 cc kit but can find no other info about the kit anywhere as far as performance or real world reliability ect. Has anyone here ever installed or ran one of these monster kits and if so how long/number of miles with the kit, general performance and satisfaction overall and any overheating or reliability issues. Also who did you use to get the cases bored ect and what was the approxomate cost for the machining? I do not mind spending the bucks such as a carrillo rod or rotating assembly balancing whatever to get the desired results which should be a super torque monster with fantastic low, mid power with a decent sot of top end power with the right pipe, carb and cam but do not want to invest in something that will be constant problems and issues. So any insight or experience with this kit would be greatly appreciated. Also the type of riding I do here in the eastern US consist mostly of tight woods,technical single track and hill climbs with very little open it up type of riding and my bike is used for 85% offroad and geared 13/48 as I have a street bike also. So any insight or comments would be great. Thanks

I Remember Dirt Rider testing this modification (1997?). The engine had more horsepower and torque everywhere.

They raced it and timed it against a totally stock 650L. No matter which rider, each of the riders always made it around the track faster on the stock one.

Their comments were pretty much the same though. The 720 kit was more fun, especially on asphalt. It felt faster around the track even though it wasn't. Maybe they just chose better lines with the stock bike.

If you do all that to the L you will have put $2,000 into the motor, maybe more, and still have $1,000 left to put into the suspnsion..an L built that way is just not going to hold up...and is not meant for the type of riding you are describing....IMO anyway...

If you do all that to the L you will have put $2,000 into the motor, maybe more, and still have $1,000 left to put into the suspnsion..an L built that way is just not going to hold up...and is not meant for the type of riding you are describing....IMO anyway...


I have over 2000 hard miles on my built motor (see my garage for details) granted these are road miles as my bike is a supermoto.

The 720cc kit runs the same compression as my 644cc motor, 10.25:1. Why would the motor not hold up? The only thing that would kill a motor built this way is excessive high rpms, like 1 hour at redline on the highway.

Tight trials would be fine, just not fun on a bike that weighs 300+ pounds. Hill climbs are usually over in a few minutes.

I agree, from what he is describing, a different bike would be better.

P.S. it doesn't cost $2000 to build the motor unless you have someone do it for you.


I understand that a lot of people don,t agree the "L" is the bike of choice for a lot of the riding I do but I can honestly say that even though the "L" will work you to death at times I just really overall like the bike and I am very happy with it. I actually had found a 650r that was already plated and really low usage that looked like it had just come off the showroom floor a couple of years ago that I could have bought but decided not to so a buddy of mine bought it instead and he is more than happy with it until it gives him a fit trying to start it at times. I have ridden that bike and yes the "R" is awesome but I still prefer my "L", don't really know why but I do perhaps it is just nostalga from old school technology (yes I am getting old!) or perhaps it is a sense of accomplishment of some sort taking that old pig and doing things that people swear the bike is not good at. So I do not disagree that there are bikes that are better for what I do with them but this one is what I have fun on and just sort of suits me. The money issue really has no bearing, sure I will have 3 times in it what it will ever be worth and it will still be an "L" just not as slow or porky as it once was. Just like the "R" my buddy ended up buying the original owner had about 7 grand in it and lost 3 grand on a bike that still looked new, so whats the difference there? Basically though as dumb as some people may think I am for doing it I am going to go with a big bore kit and the 720 sounds interesting. Basically what I have the most concerns about are overheating issues or excessive stresses on the rod or crank due to the extra weight of the piston or pressures due to an increase of almost 75cc's over stock. Also concerns are starting issues or stress on the electric starter again because of such a great increase in the size. I kind of wonder that if these kits were introduced 6 or 7 years ago as what I am understanding here that there would be some feedback whether it be good or bad from some people that had actually installed and run the set-up. I still hope to get that feedback and if I don"t I play it safe and do the 675 as that is tried and proven on the "L". but you have to admit a 720cc torque monster sounds pretty cool.

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