Suzuki DR650 Mini Adventurer – Turning the DR Into a Mini Adventure Bike – Part 3

Stock BST40 Versus FCR40 DR650 Carburetor

Part 3 of our Suzuki DR650 Mini Adventurer

Turning the DR Into a Mini Adventure Bike series will focus on the Changes and Improvements made to my 2013 DR650 after a full Summer of testing and our full-gear TAT Trial. My mission…..still very still clear – build a purpose bike on the Cheap. This segment will spill-over into Performance and how to make your DR more enjoyable.

With a Jet Kit and tuning, the carburetor performance was improved on the stock BST vacuum carb. Improved means it would now idle and was a lot easier to start. I wanted more. Off-idle grunt and tight maneuvering response was still poor – No let’s make that Lame. The problem? That big vacuum carburetor was still delivering soggy low-end performance and it took seconds for the vacuum slide and needle jet to actually settle down and feed the “right mix” every time you whacked the throttle open.

Imagine this – You pull the throttle open and that huge 4″ (100mm) single cylinder engine with it’s Small Block Chevy sized piston wants to inhale lots of fresh fuel and air “NOW”. The process in the stock BST carb of reading the change in vacuum then having that vacuum raise the slide, the rising slide opening the throat for air, while raising the jet needle out of the main jet so fuel can be pulled from the fuel bowl…..Yea, it takes about as long to read this as it does to get the DR some air/fuel! Now do this 15~20 times a minute on rough trails and you’re on board with me. The big DR can do better.

DR650 Stock Vacuum BST Left vs FCR Manual Pumper RightThis vacuum business might be OK for road machines that just have to move from one red light or one intersection to the other, but it stinks off road (there are more descriptive words).

Flat Slide Pumper Carburetors have a manual pump that “squirts” a big gulp of fuel right into intake tract every time the throttle is opened. The slide (air valve) is direct – no vacuum. When you open the throttle, the slide mechanically opens right then. Instant, Now, in-your-face, no lag, no waiting, and never soggy. The difference is amazing and has made my off-road riding so much more enjoyable.

DR650 Stock Vacuum Petcock vs Manual YamahaYamaha Raptor Petcock is ManualIs adding a Flat Slide Pumper Carburetor to your DR650 for everyone? No. If you are using your bike to commute and leisure riding on back roads then you probably don’t know there is a problem. You probably don’t need the surgical timing and control of your power down low, so you won’t use the improvements. I could not feel any improvements in top-end and roll-on power above 3,500 rpm. This modification would be for the off-road rider who wants awesome control and response right off the bottom to the top. It’s not cheap, it’s not a simple bolt-on, and parts have to be made for it to fit.

Stock DR650 Rear Pipe vs Yoshimura 2-Piece

You’ll also have to change your tank petcock to a manual one. Don’t let that stop you – Imaging roosting chunks of real estate with the rear and lofting the front with just a blip of the right hand!

Exhaust – OK, so one of those polished, shining exhaust systems has been catching your attention for months now, right? Hmm, which one to get? For me, the pick was easy. My local Suzuki dealer had an advertised special on the Yoshimura slip-on. The Yoshimura slip-on is very well made in the areas of fit and the welds. I didn’t like the red decals, so those had to go. With a heat gun and a few minutes, those would never bother me again.

6 Pounds for the 2-Piece Yoshimura
The factory-stock head pipe is Stainless Steel, so you can remove the black paint and polish to match your new exhaust. I used a bead blast cabinet, fine sandpaper, Scotchbrite, and lots of elbow grease to get mine to a mirror finish. Be sure to clean/grind the inside of the head pipe where the engine flange is welded to the outer pipe. The factory certainly could have spent more time on that joint for sure.

Stock DR650 Exhaust Over 12 Pounds DR650 Yoshimura Pipe Without Stickers
The Yoshimura slip-on is two pieces and together they weigh just a few ounces over 6 pounds. The factory exhaust (minus head pipe) weighs 12 pounds. I eat too much and tend to pack more gear than needed, so saving weight is NOT a good excuse for my purchase. Here again, adding a performance exhaust is not for everyone. It’s loud, everyone will know you’re either behind them or in front, and keeping the revs low in traffic might prevent getting tickets – again might. The book says 92~93 decibels MAX, I say full throttle and 6,500 rpm and you’ll hear every one of them.

Pessimism? Negativity? Distrust? Worry? Yes.

Will the big DR650 always start? No. The battery is fine when new and kept fully charged. There is No Kick-starter. Before you wonder which planet I’ve been on for the last 20 years, I remember that kick-starting was removed from most machines years ago. On most, you can get a jump from a passing car or get a push and do a bump-start with a rolling bike right? Yea, on Pavement. Try bump-starting any of the big singles – the DR650, the XR650L, or the KLR650 on dirt, soft sand, or mud and live to tell about it. The DR650 slides and locks the tire on pavement when bump-starting. Try it off-road and you’ll quickly park it and start walking.

OK, so between marginal battery power, soft terrain, low gearing, and No kick Starter, should we just quit riding where the pavement ends? NO! (you wouldn’t listen to me on this anyway). While being stranded is a very real threat if you were to leave the key on, run with an old battery, or have any hiccup with the charging system, there is something we should and must do

2 Solutions and I recommend Both

1) Purchase and Carry one of the small, Micro Start battery systems. Mine is the XP-1 by Anti-Gravity, but there are now dozens of offerings on Amazon from what I believe is the same manufacturer at much better pricing. Any of these should give you the “jump” as long as you get the 12,000 mAh or more. These will also add time to your cellular devices during the trip for those emergencies or just catching the latest YouTube releases.

AMAZON LINK
Micro Start Antigravity Batteries SEARCH

2) Purchase or Make and Carry a “bike to bike” Battery Jumper Cable. I made one that I can stretch between 2 bikes. This would allow me to Receive and Give a jump to a riding buddy. Mine plugs into my Battery Tender and is marked with Red heat-shrink on the other end for clear polarity matching.

Antigravity Batteries Micro Start XP 1Battery Tender Extention Cord For Jumper

This is a good stopping place, so I’ll end my story here. Next time we’ll take a look at soft luggage and packing for camping and other trips off the road.


Thanks for following

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