DRZ400 Adventure Bike Build

This adventure bike build article takes a stock DRZ400 and steps through each of the adventure upgrades to convert it into a very capable DRZ400 adventure bike. This is the third DRZ400 I have built into an adventure bike and the products used in this build are based on over 5 years of riding DRZ400 bikes for extended adventure riding and camping trips and clocking up over 100,000 km of adventure riding Grade 1 to Grade 5 tracks.

This DRZ400 adventure bike was built up especially to be shipped to Australia for a one month trip through the Red Centre including the Simpson Desert crossing. It proved to be a brilliant adventure bike build and capably completed the trip. Aside from that, it was a great fun bike to ride. 

The final result after many hours in the workshop
2016 DRZ400E L7 strip down
For an older technology bike the suspension on the DRZ400 is fairly respectable. However it is sprung and set up for a midweight rider, not all the additional weight that comes with adventure riding such as extra fuel, water, tools, cooking gear, sleeping gear etc. With this in mind the first thing on the list was to strip the bike down and remove everything that needed to come off for upgrading plus pull out the suspension and send it off to Moto SR for a respring, revalve and 1 inch internal lowering.
DRZ400 suspension upgrade
Softening the DRZ400 throttle - Throttle return spring anchor relocation
The link below shows the process of how to reduce the tension of the throttle return spring and reduce fatigue on long riding days
Upgrading the Keihin FCR39 needle and main jet
After playing with a few different exhausts, needles and jetting combinations over the years I found a setup on the Keihin FCR39 that performs well for adventure riding. Click on the link below for more information on DRZ400 needle and main jet upgrades.
Buy this performance needle/jet
Adding a hand tune pilot jet to the Keihin FCR39
There is nothing wrong with the standard Keihin FCR39 pilot jet (mixture screw) other than the fact it is tucked up into the carburettor body meaning it can't be easily accessed or tuned by hand. The link below shows the process of installing a hand tune pilot jet which will make life easy when making mixture adjustments.
Buy this hand tune pilot jet
Keihin FCR39 breather hose plumbing for deep water crossing
An upgrade to the Keihin FCR39 slant's breather hoses must be made in order to successfully tackle deep water crossings. The link below shows the process of replumbing the breather hoses
Fitting a S/SM subframe
The DRZ400S/DRZ400SM subframe has foot peg mounts that fit the RemoteMoto luggage racks so a new S/SM subframe was fitted
Buy this subrame
Helmet lock removal
The helmet lock is a heavy lump of steel with a large alloy plate which is rendered useless with the luggage blocking access so it is removed. The link below shows how it is removed cleanly
DRZ400 3X3 airbox mod
The 3X3 airbox mod is the opening up the airbox inlet to a size of 3 inches x 3 inches to increase airflow. Teamed up with upgraded jetting and a performance exhaust it provides a noticeable performance improvement.
Reference Link : DRZ400 3X3 Airbox Mod
Installing an oil temperature sensor
With aftermarket accessories that restrict the airflow across the engine and an increased luggage load, it can mean in the slow/steep/technical terrain, the engine temperature can rise alarmingly. This is amplified on days where ambient temperatures are high. Because of this, I install both water and oil temperature sensors to monitor temperatures and make sure the engine temps stays at a healthy level. The link below shows the article on installing an oil sensor to the DRZ400
Buy this 10mm fin sensor
Installing a water temperature sensor
The DRZ400E doesn't have a water temperature sensor installed from factory and while the left radiator does have a threaded bleeder hole that can be used to screw in a temperature sensor, there are two reasons I prefer not to use this location. Firstly the cable on the temperature sensor makes it a hassle when you want to bleed the radiator system of air. Secondly the DRZ400 can get small air pockets in the left-hand radiator resulting in the temperature sender giving incorrect readings. The link below shows fitting a Trail Tech 19mm inline temperature sensor unit which is a far more reliable and accurate way of monitoring water temperatures and allows you to still use the left radiator air bleeder.
Buy this 19mm hose sensor
Side stand switch removal
Side stand switches are always on the hit list for removal when aiming to build the most reliable adventure bike possible. The link below shows the process of removing the DRZ400 side stand switch in a clean, tidy and reliable way.
SH775 regulator/rectifier upgrade
The link below explains how the upgrade to a SH775 regulator/rectifier improves reliability and increases voltage
Reference Link : DRZ400 SH775 R/R Upgrade
Buy this SH775 R/R
Wiring up an accessories power feed directly from the battery
DRZ400 aftermarket triple clamps
To pave the way for a Scotts stabiliser, the Scotts/BRP SUB mount was fitted. The link below shows the process to install the Scotts/BRP SUB mount triple clamp and Scotts stabiliser
Buy these SUB triple clamps
Fitting the suspension and wheel set
Fitting the fully rebuilt suspension from MOTO SR and fitting the wheel set
Buy this wheel set
Fitting the exhaust system
Fitting the Yoshimura RS-2 Comp Series full exhaust system
Buy this exhaust
Installing a Trail Tech fan
I've never found the DRZ400 to overheat when there is plenty of air movement past the radiators, however when riding tight, steep, slow going tracks when air movement past the radiators is reduced and either/both the engine is working hard or ambient temperatures are high, the DRZ400 can overheat in fairly quick time. Installing a fan solves this problem and ensures the engine stays at the right temperature. The link below shows the install of a Trail Teck fan kit
Buy this fan
Fitting a kick start
One of the key reasons I ride a DRZ400 is that it has a kick start. The S, SM and road registered E don't have one from factory but the DRZ400 engine does support both an OE and aftermarket kick start kit. It is a relatively straightforward install and can be knocked out in a comfortable 2 hour workshop session. For solo riding in remote places a kick start is invaluable and while I have only had to use mine about 5 times in the last 6 years, I have been so glad to have had it in each of those cases
Buy this kickstart
DRZ400 clutch cover protection
The factory DRZ400 outer clutch cover is thin magnesium and very susceptible to cracking in a drop or crash. Whilst case savers adhered to the outer clutch cover will improve protection, the billet machined alloy case cover offers a significantly improved level of protection. It also goes without saying the billet machined cases look very sharp. There are a number of companies producing billet machined alloy case covers for the DRZ400 however the one fitted here is produced by Force Accessories
Buy this clutch cover
DRZ400 decompressor
In combination with the kick start the decompressor is installed. The link below shows the install process
DRZ400 starter clutch bolts
The current DRZ400 models do not have the early issue of the starter clutch bolts loosening, backing out and then contacting the stator. With regard to the catastrophic results if this were to happen, I always check anyway as it is a simple 15 minute job and gives peace of mind
DRZ400 Gear Shift Lever Fix
From factory the DRZ400 gear shift lever has a sharp protruding section of metal. When the bike is dropped or crashed it can concentrate the impact on a small area of the magneto case and can crack it. The fix is simply removing the protruding section of metal
1 1/8 Renthal Fat Bars
A set of 1 1/8 bars are always a far superior option over the soft as butter stock 7/8 bars. There are a number of good options on the market but I am quite fond of the Renthal 603 bend in combination with the BRP SUB mount triple clamps for adventure riding
Buy these bars
DRZ400 tail tidy
The link below has more info on taking the horrendously large and ugly factory tail assembly and exchanging it for a much smaller and tidier looking option
Reference Link : DRZ400 Tail Tidy
Buy this tail tidy
DRZ400 clutch switch bypass
The DRZ400 clutch has a safety switch from factory. Removing the clutch switch improves reliability as it is one less electronic component susceptible to failing and giving you grief out on the trail. The link below shows the simple process to bypass the DRZ400 clutch switch
While the stock DRZ400 grips aren't all that bad, I'm a fan of nice grips and to go with this bike's white, black and blue colour scheme, I installed some white and blue Scott Diamond Grips
Buy these grips
Iridium CR9EIX plug
For the advantages over stock plugs, an iridium plug was installed. A temp range one cooler than stock (CR8E) is used to help on the hot days where the bike is loaded up and working hard in the slow going terrain
Buy this spark plug
Breather hose clamp upgrade
Replacing the stock pressure clamps on the breather hoses with stainless steel hose clamps to ensure a 100% watertight seal when crossing deep water
DRZ400 front rotor upgrade
The factory DRZ400E front brake is respectable. It is by no means outstanding, but it serves the purpose of stopping the bike well. However, when the DRZ400 is used as an adventure bike and carries all that extra weight, the limits of the small 250mm front brake rotor are exposed. Upgrading the front brake rotor from a 250mm to a 270mm adds that extra bit of stopping power that makes riding more enjoyable, and braking more effective. On this build I have installed the Galfer 270mm SKW oversize rotor kit which comes with the 270mm rotor and brake calliper adaptor
Buy this brake rotor kit
DRZ400 rear rotor upgrade
Like the front brake, the rear brake on the DRZ400E is respectable, but it has one major issue when carrying all the extra weight out on an adventure. The rear brake can suffer from brake fade when descending steep sections and the brake is applied heavily for long periods. Changing pads to other compounds can improve the situation slightly but what I have found to be the best solution is replacing the factory rear rotor with a wave style rotor that offers extra thermal dissipation and allows the rotor to handle prolonged/heavy use far better
Buy this brake rotor
DRZ400 gearing for adventure riding
The wide ratio gear set cures what is the DRZ400's biggest Achilles heel, that being, a shallow gearbox cluster. I have one installed on my main bike and it is brilliant. It completely changes the character of DRZ400 engine. This bike however was built on a timeframe that didn't allow the wide ratio gear set to be installed so it is using what I find to be the best compromise for adventure riding with the factory DRZ400 gear set. A 15/44 or 14/41 (exactly the same ratio) provides tolerable open road cruising while still being geared low enough for technical terrain, albeit with a bit of clutch feathering in the really steep gnarly stuff. I always fit steel sprockets over aluminium favouring longevity over weight. I normally use JT or RK sprockets.
Buy these sprockets
DRZ400 case saver / sprocket cover
The factory case saver/sprocket cover doesn't shed mud and clay very well and regularly becomes clogged. There are a number of aftermarket options that shed mud and clay far better with the B&B Engineering one fitted here being one of the good options
Buy this sprocket cover
DRZ400 magneto cover protection
The magnesium engine side cover is very susceptible to cracking if the gear shift lever is shunted into the engine in a drop or crash. A case saver adds an extra layer of aluminium protection to avoid this and does a very good job. There are a number of case savers on the market with the ThumperTalk ones probably being the most common. The one I have fitted here is a B&B Engineering case saver however there are plenty of similar options on the market
Buy this case saver
DRZ400 gearshift lever verticle adjustment
Large adventure riding boots makes it awkward to shift gear when the lever is in the factory position. Rotating the gearshift lever clockwise one spline makes it far more comfortable to ride and shift
DRZ400 gearshift lever horizontal adjustment
The gearshift lever can rub against the case saver and end up looking ratty. Using a hydraulic press, you can gently coerce the lever to sit out further which creates space between the lever and case saver avoiding the contact that causes the damage
DRZ400 kickstand shortening
Because this bike has had the suspension lowered internally by 35mm, the kickstand needs to be shortened so the bike doesn't risk falling over. The link below shows how I shorten kickstands
DRZ400 master cylinder guard bolt upgrade
The two factory button head hex socket bolts that secure the alloy protector for the rear brake master cylinder and reservoir have very broad heads. These bolts can bind themselves to the alloy protector when you try and remove them and can strip the head hex. To avoid this, the factory bolts can be replaced with bolts with smaller heads which reduces the surface area that causes the binding and they undo relatively easily
DRZ400 bashplate
The all-important bash plate was added. While there are a number of good options on the market, I've used B&B Engineering bash plates since 2007 and they have been excellent. The one fitted here has their new black polymer option
Buy this bashplate
Rear rotor protection
For added protection in rocky terrain, a Force rear rotor protector was installed. These are very tough units
Buy this rotor protector
Brake caliper protection
Primarily for protection of the brake calliper bleeding nipple, a Works Connection rear calliper guard was installed
Buy this calliper guard
DRZ400 large tank
There are a few large tanks available for the DRZ400 but on all my builds I go with the Safari 28 litre. Good solid tanks and great capacity for those long legs
Buy this tank
DRZ400 aftermarket seat
The factory DRZ400 seat is narrow, firm and uncomfortable for long distance riding. There are a number of aftermarket wider and comfier seats the market with Seat Concepts being one of my favourites. The seat fitted here is a DRZ400 Seat Concepts standard height seat and I had it recovered in white to match this build
Buy this seat
DRZ400 aftermarket front fender
The DRZ400E has a front fender that looks like it has come directly from the mid-1980s. It may be functional but it is downright ugly. I've spent years trying to find a nice looking fender that is a direct fit however the DRZ400 doesn't share a common bolt pattern so there is no off-the-shelf option for a modern front fender that looks good. I like the look of the KTM fender and while some call it blasphemy, I'm happy to fit one to the DRZ400. The KTM fender are not a direct fit to the DRZ400, in fact there is quite a bit of mucking around, however the outcome looks good and is well worth the effort. The front fender fitted here is an aftermarket KTM690 guard
Buy this front fender
DRZ400 adventure screen
The RemoteMoto V3 Spec Adventure Screen fitted to this build was designed to firstly provide a large and robust dash to mount equipment for navigation, rider tracking, engine monitoring, charging, etc and secondly, to provide wind protection and reduce rider fatigue on long riding days. The V3 Spec design has evolved and been refined from over 90,000 km of riding on the RemoteMoto DRZ400 route logging bike while logging hundreds of GPS adventure routes for the website. Having just about everything thrown at it from New Zealand's challenging riding terrain and demanding weather conditions, it has proven itself to be a robust and effective adventure bike upgrade. It was a no-brainer to fit this adventure screen as I really enjoy riding with them
DRZ400 radiator guards
These are custom DRZ400 radiator guards designed specifically for large tanks without interference.
View DRZ400 Radiator Guards
DRZ400 coolant overflow
The RemoteMoto coolant overflow tube fitted here has been designed to fit the RemoteMoto DRZ400 radiator guards. The coolant overflow tube is ideal if you have upgraded to the SH775 regulator/rectifier and have been forced to remove the factory coolant overflow tank. A nice looking unit plus very easy to keep an eye on coolant levels. Note: this product will be available for purchase soon.
I am a huge fan of steering stabilisers and the Scotts stabiliser and Scotts/BRP SUB mount provides both steering damping plus acts as a bar riser avoiding the need for stacker risers which don't look anywhere as nice as the billet machined Scotts/BRP SUB unit. The link below shows the process to install the Scotts stabiliser and Scotts/BRP SUB mount triple clamp
Buy Scotts Stabiliser
DRZ400 indicator relocation brackets
The 28 litre Safari tank does not allow for the stock indicators to be mounted without hitting the tank at full lock. These relocation brackets were fabricated using 3mm aluminium plate and aluminium standoffs. Note: this product will be available for purchase soon.
Fiberglass panniers
Being a fan of hard luggage, RemoteMoto fiberglass panniers were fitted. Note: these panniers will be available for purchase soon.
Bottle cages
To hold 4 X 1 litre bottles the RemoteMoto bottle cages were fitted. Note: these bottle cages will be available for purchase soon.
Internal bar heaters
I am a fan of internal bar heaters so I can run my favourite grips. The link below shows the process of modifying a set of Polly Heaters to fit 1 1/8 bars
The wiring of the bike is centred around negative spade connector common rails and fused positive spade connector common rails fed from a relay. All the wire to wire connections use shrink crimp connectors
DRZ400 hand guards
Years of using Barkbusters has sold me on their products. For fitment and durability there was no question when it came to fitting hand guards
Buy these hand guards
DRZ400 pivot levers
The stock DRZ400 levers are not adjustable and fairly horrid to use off road. While there are a number of options for the DRZ400, I really like the adjustable Zeta pivot levers and have been using them for years
Reference Link : Zeta - Pivot Levers
Buy these levers
Starter idle gear cover bolt upgrade
The stock bolts holding the starter idle gear cover in place have very broad heads. These bolts can bind themselves to the alloy gear cover surface and normally require an impact driver to remove them. If you are forced to do a stator replacement mid-trip without access to an impact driver, you can find yourself in a jam. By replacing the stock bolts with allen heads bolts this allows you to use an allen key and remove them with relative ease
Double take mirrors
The stock DRZ400 mirrors are heavy, break easily and can prove costly to repeatedly replace. The double take mirrors are a great lightweight, durable option that conveniently fold away when you are riding bush tracks that can have branches catch the mirrors
Buy these mirrors
DRZ400 chain guuide
Photo 59 of DRZ400 Adventure Bike Build
The stock DRZ400 chain guide is alloy and can bend easily when given a decent smack. The TM Designworks Factory chain guide is a simply brilliant product that not only looks good, but it is bulletproof
Buy this chain guide
Motion Pro LiteLoc Rim Locks
Photo 60 of DRZ400 Adventure Bike Build
To help reduce the number of wheel weights used, the Motion Pro LiteLoc Rim Locks are used front and back
Buy these rim locks
GoldenTyre 723
There are a number of good tyres out there and everyone has their favourite, but on this build a set of GoldenTyre 723 were fitted due to them being a simply brilliant adventure tyre
Buy these tyres

The final result 

After many hours in the workshop, this is the result 

A photo from the 2017 one month adventure ride through Australia. Good times!
Author of this article: RMOTO