Chief Gunner 2 Posted October 31, 2008 We have a few newer members who have stock XRL's I PM'd a couple of them and offered assistance anytime. I also recommended the de-smog and carb mods to them as well. These two mods add an average of 5-8 HP to a bone stock XR Which is pretty impressive if you think about it, without modifying the engine and spending allot of $$$. For the HP gains you get it's a very cost effective way to get a little more performance out of such a low compression air cooled engine without affecting reliability. I got all of the stuff for my pig at XR's only but there is a local alternative if they do not want to wait a few days for the kit to ship......Baja Designs in San Marcos has what they need here: https://www.bajadesigns.com/NET/item_detail...ItemCode=151020 Here's a link to a great source of info on how to do it all to your XRL's http://www.4strokes.com/tech/honda/ I'll be giving my VMax a tune up and working on the Husky today and tomorrow so if there's any XRL owners who might want a hand with their pigs just shoot me a PM and I'll reply with my phone number and address. Share this post Link to post Share on other sites
Strega 0 Posted October 31, 2008 Nice of ya to offer up your place for workin on bikes again. I had a fun time at the last Gunner extravaganza Share this post Link to post Share on other sites
tntmo 912 Posted October 31, 2008 If there are a few people in the know, you shouldn't have to buy a desmog kit. I made my own and it was a snap. It's a pretty simple procedure, doesn't do anything for horsepower but it does remove a bit of weight and reduces the hoses/lines on the carb. Share this post Link to post Share on other sites
Chief Gunner 2 Posted October 31, 2008 doesn't do anything for horsepower but it does remove a bit of weight and reduces the hoses/lines on the carb. I disagree ...depending on the engine type it might or might not work. On the XR650L it does work... If you examine the interior drawings and schematics of the XR650L engine you will see that the ports for the charcoal / evap canister lines are also internally ported inside of the cylinder head up to and part of the exhaust ports of the XR650L's engine. When the piston is coming back up on the exhaust stroke having the ports blocked off helps keep the compression in the higher end (which is only 90 to 110 PSI minimum on the stock XRL). Sort of like the scavenging effect of a two stroke where the shape and diameter of the exhaust actually helps the compression.... If you were to do a compression check on an XR with a smog block off and one that has the smog equipment still on it and compare the two you would notice a 10 to 15 PSI difference in the compression with the blocked off engine having the higher ratio of the two. It was doing the homework on this, that convinced me that it works. The California model XRL's are the most lean and most "choked" models sold anywhere in the US.....so with that said.. Aside from the block off, the combination of the re-jetting and use of a more free flowing air filter (like a K&N or a UNI) and a less restrictive exhaust allow the 650L engine to breathe much better. Running richer on an air cooled engine actually helps to keep the internal temps down. My bike runs anywhere from 20 to 25 degrees cooler on average when it gets hot than it did when it was stock. I bought and installed an XR's Only thermo dipstick before I tore into it so I was able to see the difference. So my friendly argument is this....higher compression, richer fuel mix with a better inlet flow of air and exhaust = a cooler engine with more unrestricted air flow which will make more horse power without modifying internal engine parts (piston, cam, valves, rods etc). But then again there is only so much you can do for an engine that only makes 30-40 HP at best without serious engine work. Share this post Link to post Share on other sites
