650l questions

I have stumbled across some numbers for gear ratios for the 650l and the 600r. It appears that all of the drive gears are the same except for first (which is shorter on the 650l). DOes anyone know if this is correct?

Also, if the gears are the same, then what other changes may have been made in the tranny on the 650l (heavier flywheel, taller primary drive, etc).

Reason I am asking is that I am thinking about stripping mt 650l down to its bare essentials, running 14/48 gearing, and putting on IRC knobbies (stock for 600r - rear anyway) and will I have a bike very similar to the 600r (other than the short 1st gear, electric start with battery, lower compression, larger displacement).

My other option is to put a 600r engine in my frame.


If you do this, you still will not have a 600R handling bike. Yours will still be heavier. Your compression ratio is lower, but by adding the 50cc, you in fact have more rear wheel hp than a 600R. It is my understanding that most of the internals on the 650L are the same, clutch etc. The 650L was derived from the 600R. They are the same except for minor suspension/spring rates, and the carbs, the R's is smaller. The plastics are of course different. The 600R, I believe has a 9.5/1 ratio. If you strip everything off, you will still be heavier, but with a front and rear sprocket change, if you'll only be riding in the dirt, should be all you need to do. Make some exhaust, and a cam change and you will still beat the 600R, even by a larger margin. Try raising your piston ratio to 10.5/1. The 600R's only advantage against a striped "L" would be on tight trails. Open woods or roads and you should beat it stock. The "L" has about 35 rear wheel HP. The 600R has less than 30hp. Against the new 650R you will need major work to beat, 40+hp, anything short of a 1/4 mile race, you'll be lucky to keep up. If you want a 600R so bad, sell the "L" and buy the new 650R. But don't waste money going backwards.

For 1398.00 White Bros. has a kit to give the "L" 50 rear wheel HP, check out their site.


I've got a 96 XR650L that I have ridden hard for three years. I use 14/48 sprockets and a Regina X ring chain. Sunstar sprockets have held up very well. As for the front tire I run a dunlop D707F and it holds up well on the road but not legal. The rear tire Ive kept stock ,I tried an enduro tire but the roads tore it up. this bike is my daily ride to work. I ride with a buddy who has a 98 XR650L set up the same. the sprocket set up will hold wheelies through 5th gear down the road. You could get a light weight battery? My biggest draw back with the bike has been its weight and pushing in corners even when hanging your foot at the front tire and practically sitting on the tank. Don't get me wrong I love the bike BUT the suspension just doesnt cut it in the dirt, as far as jumping goes. This has what made me buy a second bike ----2001YZ 426 F So I ride dirt at lunch time work days on the XR and kick ass on the YZ on the weekends. O yeah I also use a 15 weight oil in the front forks. Mechanically the engine is indestructable! Roost on Dan :)

I have thought about the 650R option but it isn't street legal and baja conversions aren't easy in NC if possible at all. The spring rates for the 650l are actually stiffer than the 600 R. .44/10.5 650l as compared to .41/10.0 600r so if I could drop the weight, I would end up with a better jumper than the 600r.

I know the starter and battery are weight that cannot be entirely lost but relocating a smaller battery along with that other stuff in the bolt on box would help me drop some weight. Also, I did forget to mention that part of my plan is to replace the CV carb with a regular dirt carb. If there is a difference in the flywheel weight, then installing the lighter one should improve throttle response and lighten the load a bit.

I also have a 600r rear fender already and that will shave a pound or two off of the rear.

If your gonna get a new carb get a pumper carb. SUDCO.com has a Kehin 41mm pumper complete for 475.00. I'll have it by late spring. Along with a White Bros. cam and a JE 10.5/1 piston. I just got my WB e-series exhaust and oversize header today! I'll let you know how they work after X-mas.


Please do!! I have looked at the Keihin pumper and wondered if itwould be a huge difference on what seems to be an underpowered bike as it is. I know I won't begoing 10.5 piston, cams, or headers until it is rebuild time.

I have a '93 650L that had 12,500 miles on it and was still running strong. I had Thumper Racing install the 675 10.5:1 kit with the lightened flywheel. I also have a 41mm flat slide Mikuni, but I've had it longer than the pumpers have been out, so it is not a pumper. I intially installed the carb when the bike had about 3,500 miles on it and noticed a dramatic increase in cold starts and low-end resposiveness. I don't rev my bike much, I prefer to short shift it. The carb does run out of steam if you want to rev it, not any less than the stocker, more noticeable since it is more responsive down low, I don't reccomend revving the 650L anyway. The stock carb was a 42.5 CV, which might might be the reason the 41 is more resposive down low. Thumper racing advised me to go back to the stock carb with the 675 kit, or a pumper, that the 41 that I have works better with the 600's. I still have the 41 on it because it'll cost about $70 to make the stock carb work with the 675 kit. I'm thinking about going with the pumper in the future because I also had an XR440 kit with the pumper and it was awesome. The 675 is much more responsive now, especially down low, I can't imagine what it'd be like with a pumper carb too. I did retain my cable choke when I installed the 41, it can be hard to use a choke lever with the IMS tank. Has anyone heard of the newer Edlebrock carbs? They are supposed to have a pumper too, but don't know much about them. As far as doing this all over again, I'm not sure if I would, maybe I'd try a carb and pipe, then ride the bike 'till it wore out first. If I had or wanted to go into the motor, I would reccomend the 675 kit. The lightened flywheel is a misconception, the bigger piston more than makes up for the weight trimmed from the flywheel. Thanks for all of this! Mark

Since you already have the 675 kit installed you could still contact sudco.com for there recommendations on carbs. They have larger than 41mm's available. In reference to the edelbrock carbs, (pumper), it is not available for the "L" series 650. They make one for the 600R which is basically the 600 bored out. They did make a qwuik series carb for the "L", but its not a pumper. I've spoke to edelbrock and they advise if the manifolds from a 600 will bolt on to the 650 it should work, but its a retro fit not a kit. Also the air box side has to be the same as the 600 or you will need to alter it. The pumper will dramatically improve low end performance and should be only better than stock at high end. The 600R comes with a 38mm carb. The edelbrocks are oval shaped like 34x40mm not a round 41mm.


PS: Check out www.groups.yahoo.com/group/xrlug, this is an XR650L group only and you'll get alot more feed back. I don't know if your aware of this group.


I tried to get on that XRL site , but could not pull it up . Is that the right name?

I guess it's different until you join the group. Try http://www.groups.yahoo.com, then search XRLUG, XRL-Users group. I don't remember how I found it. or search XR650L.


if your looking for a car the quicksilver carb with a pumper is great you have to have it retro fitted I have it on my xr650L and it made a great difference in bottom mid and top. do all of you modes on the bike before you buy the carb the factory will set it for you to what you have on your bike they did a pretty good job for me, I hardy have to choke it on a cold day too.

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