When I ask her if Jesse is available to speak with me about a DR650, she answers in the affirmative and puts him on. The time is a little after 8 am Monday morning and according to their website they are open for business, so I call the number and a woman answers confirming I have reached Kientech Engineering. Jesse's name and phone number appear prominently on the banner at the top of the page, and just below that I could hardly believe the address I saw in fine print a place nearby! I found that Kientech Engineering has them for just $15. So tell me what the magical settings are then.įirst I apologize for being a shameless name dropper, but I am so stoked by what transpired yesterday I have to share it.Īfter wading through so much discussion about tuning the BST40 here and on other websites, I finally decided it wouldn't hurt to take the bold step of shimming the needle and getting the extended fuel mixture screw. Try different jetting and learn what too lean and too rich feels like! The BST Magic thread was developed for guys to get almost perfect jetting for virtually no cost. It only takes two minutes to have the needle in your hand, (with the stock tank) so there is no excuse. The DR is pretty mild and will tolerate pretty wild variations but will still run best and get the best mileage when jetted right. In my experience, after 45 odd years of two and now four strokes. Very slight changes in jetting between the same model should be all that is needed if they are running the same carb and exhaust.
one method/setting/size can never be applicable to all. Jetting is such a subjective issue with so many variables involved. I guess that only a Dyno could determine that? am I at the apex of what the motor is giving me for power? I have no idea. Could it pull even harder? I just do not know. Bike runs very well though and pulls hard throughout the entire power band. The exhaust end of my DG is getting blacker than normal but I ride with a heavy throttle hand and it's very hard for me to determine my actual mileage. In Australia many are running over two needle positions leaner with a tapered stock needle and slightly opened air box. They may work well under 32f (0c) but don't be scared to try lower needle positions. The jetting kit instructions, as they admit err on the rich side. You will spent 80% of your time there so, in my opinion the needle needs to be in the right place. The DR is run mainly on the needle circuit, 1/8th to about 1/2 throttle. As MXROB and others say, if your not getting 50mpg or over your just too rich. Dozen's of riders are now on these settings and seem happy with the results. 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).Auscanvet wrote:Thanks MXROB, your truly a legend!! The BST Magic thread works great for Australian bikes. Try it off-road and you’ll quickly park it and start walking. The DR650 slides and locks the tire on pavement when bump-starting. 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. 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.
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. The battery is fine when new and kept fully charged. 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 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”. Off-idle grunt and tight maneuvering response was still poor – No let’s make that Lame. Improved means it would now idle and was a lot easier to start.
With a Jet Kit and tuning, the carburetor performance was improved on the stock BST vacuum carb.
Manual for a bst40 carb how to#
This segment will spill-over into Performance and how to make your DR more enjoyable. My mission….still very still clear – build a purpose bike on the Cheap.
Manual for a bst40 carb full#
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.