Top 5 Inexpensive Mods for the Honda XR650R

Inexpensive modifications to get the most out of your Honda XR650R

Published Jul 24, 2007 by ridered
Last updated on Jul 24, 2007

The XR650R is a great all around dirt bike. However, there are a few easy modifications that can be done that will make the beloved BRP (so affectionately called The Big Red Pig) more fun and enjoyable to ride. You do not have to be a master mechanic or have tons of money to try these mods.

Mod #1 - Unleash The Beast!

The stock version of the 650 is a fun but rather tame ride. Like many stock bikes, it comes from the factory all choked up with restrictions on air and fuel intake. Although the bike runs well, it can run so much better. Why not get all the power the bike has to give?

By far the best modification is to "uncork" the bike and let the monster loose!

The process to uncork the bike involves replacing a few restrictive parts and removing\replacing the tailpipe "cork". For detailed step by step instructions on uncorking your BRP, check out Bobs Uncorking.

Basically, uncorking the XR650R involves replacing an air intake with one that allows more air into the carb. Now that the BRP can breathe properly, the air\fuel mixture will need to be adjusted. The main jet will need to be replaced with one that allows more gas into the carb. The main jet used will depend on the altitude you will be riding. This requires some experimentation on the different sizes of main jets to find the perfect one for your riding location. Now that the beast can breathe properly, it needs to exhale with as much force as it inhales. The tail pipe has an insert that can be replaced with one from the dealer for around 200 bucks. This insert allows more exhaust to flow. A much simpler and more economic way is to simply drill out the insert in the stock pipe.

To do this you will need to buy a metal hole saw and drill out the insert. You can find this tool at most home improvement stores for around 10 bucks. This removes the "cork" and leaves the spark arrestor in place and functional. The stock pipe with the cork removed functions very well throughout the power curve.

This mod is really a "no brainer". If you are hesitant at all, check the threads on Thumpertalk on this subject.  Uncork it and you will be amazed at how much more power is at your command! The bike starts easier, runs cooler, and is so much more fun to ride. I highly recommend this mod! You will not be able to get the grin off your face after you ride your bike uncorked. Be careful riding it the first time after uncorking, your front tire will tend to lift off the ground a lot easier!

Mod #2 - 13 Tooth Front Sprocket

The 650 is known for being the king of Baja.  Johnny Campbell has stated these famous words concerning the speed of the 650..... "Too fast, too quick!"  Although the gearing is tall for flat out flying across the desert at 100 plus MPH, the stock gearing tends to be a little too tall for woods riding.  Nothing will make your bike more suitable for tight woods riding than gearing it down a bit.  One easy way to do this is to replace your stock 14 tooth front sprocket with a 13 tooth sprocket. The 13 tooth front sprocket will do wonders if you do a lot of tight technical trail riding. It will allow you to very easily pop your front tire up over obstacles such as logs and tree roots with ease. You will be able to climb very steep technical trails without having to worry too much about stalling the bike or playing the clutch too much.  The uncorked 650R with a 13 tooth front sprocket enables you to literally tractor up any trail. Less bogging and stalling and more riding!

The bike will still go plenty fast but obviously not as fast as the taller gearing. The 13 tooth front gear is recommended if you ride a majority of the time on tight technical terrain.

Mod #3 - Replace and Raise Your Bars

If you are a taller rider, you may want to seriously consider replacing and raising your handlebars. The stock handlebar height  seems to be on the low side. This is especially true when riding while standing on the footpegs. There are a number of ways you can raise your handlebars. Some guys will purchase a new triple clamp that comes with adjustable bar risers. An economical way would be to purchase a part such as this one. This will work with your stock setup and raise your bars 3/4 inches. It is also designed to fit the big bars which is the next subject.

Do you often get arm pump too soon into a ride? Most Big Bars are designed without a crossbar which allows them to flex slightly. This will put less stress on your hands and wrists. There are a number of big bar manufacturers to choose from. Some of them have multiple custom bends you can select for your height and style of riding. After riding with the stock bars for a few years, I purchased the big bar riser kit and then installed a Pro-Taper CR High Bend handlebar. The difference is dramatic. My wrists and hands do not tire out anymore and there is less vibration. My first ride after installing the bar riser and Pro Taper bars was at Moab Utah. Anyone who has ridden at Moab can tell you that the terrain is not for sissy's. There are constant drops and crevices, the front forks get one heck of a workout. I did not have any pain in my wrists, arms, or hands. I am very impressed with this setup and am kicking myself for not doing it sooner. Check out Pro Tapers Site.

Mod #4 - Indestructible Skid Plate

If you ride a lot of rocky terrain, the stock plastic skid plate may not offer adequate protection. Probably designed with weight in mind, the stock skid plate is lightweight but will not stand up to much abuse. One alternative that I am very impressed with is the aluminum skid plate from Utah Sport Cycle. This particular skid plate can handle slamming into rocks, logs, etc. without damaging your bike. It is wide enough to protect the water pump as well. The price of the skid plate is well worth the piece of mind the next time you happen to hit into a destructive rock that is determined to cause some major damage. The skid plate from Utah Sport cycle adds protection and looks great on the 650R.

Mod #5 - Remove or Replace Your Stock Thermostat

The last thing you need is to have your engine overheat on your next ride and spew out coolant. The big bore 4-stroke engine runs pretty hot as it is, you don't want it to run hotter.

One thing that can be done to prevent overheating is to replace or remove the stock thermostat. The stock thermostat has proven to be defective on most early models. The issue is with the thermostat sticking at some point in the movement. I removed mine and sure enough, it was stuck. Some guys replace the thermostat with a similar one that can be purchased from some motorcycle parts sites or modifying certain car thermostats. Other riders simply just discard the piece of junk and do not put another one in. The debate continues on this subject. You can read about the advantages\disadvantages of removing or replacing the stock thermostat on Thumpertalk.

One advantage of removing the thermostat is that you do not have to worry about the thermostat failing you out on a trail miles away from anyone.

One disadvantage may be that the engine is not running consistently at the prime operating temperature.
Damage can be done to the engine if ran cold. If you live in a colder climate, it might be best to replace the stock thermostat with one that is not defective. An example replacement to the stock thermostat is this one from XR's Only.

I just tossed mine in the garbage and have been running with no thermostat for a few years. I just let the bike idle for a few minutes to warm up before hitting the throttle too hard. The engine temperature is stable and the engine runs well.

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