More power from dr 650??
 

My project is to take apart my dr and rebuild it.
Why??

well...:oops2:

the engine has 16000 miles on it with full service history, but the bike is looking like it would benefit from a make over.

i wasnt intending to do anything with the engine...

although....doh

why not see if i can increase the power somehow.

there is a k&n filter on it.
i know i can put an exhaust but the power gained is :confused1:...

surely there is something i can do to the engine or carb .

any thoughts people...

im starting this project after chritmas and will be keeping records and photos as i go.

im in no rush to do it.:helpsmilie:

Not sure about extra power really, maybe a flat top piston, polished ports and higher lift cam..

But do check you camshaft for wear and the head as the cam runs straight in the aluminiun with no bearings. Also check the lobes for wear. On mine the cam had scored the head and the case hardening wore on the cam lobes, also the gears were wearing at 16000 miles although cant be sure it was the correct mileage.. The other thing to check is the engine drive chain as these can stretch and may need adjusting..

The big questions are:

How much power do you want?
How much are you prepared to spend?

The DR650SE comes from the factory running REALLY weak (about 35WHP) and really rough compared to how it CAN run. You may not even realize just how poorly a stock DR runs until you start experimenting. Some people are getting over 50WHP from a DR650SE, but you may not need anywhere near that much. Just getting the bike to run smoothly, and improving the throttle response, can make the bike seem like it's putting out WAY more power, when it may be just a minimal increase that is delivered better.

The stock exhaust isn't a huge problem for power until you upgrade other things. Most people swap it out because it is a heavy boat anchor and/or they're looking for more power. More power is possible with it still bolted in place though, but it IS a bit limiting if one is going for big increases, especially the blob of weld that is usually in the header pipe. Many people grind this blob smooth for better flow.

The big initial limiters on power with the DR650SE are the stock airbox and the jetting that is extremely lean for use at/near sea level. Opening up the airbox by removing the snorkel, cutting the top, or cutting/removing the sidecover will allow the engine to breathe much easier. To better take advantage of this airflow though, you'll also want to jet the carb a bit richer. At the same time, you can improve throttle response by drilling a 2nd hole in the slide and/or trimming a slight amount off the slide spring. Research this heavily before doing so though. There is a point of diminishing or negative returns. Once these mods are made, THEN the stock exhaust will start to become a limiting factor.

I recently swapped in a richer main jet, cut the top of my airbox, swapped in an adjustable pilot needle, and swapped in an extended idle mixture screw. I still have the stock header pipe and haven't ground the weld smooth, but I do have an FMF Q2 free-flowing muffler and midpipe (light, loud w/heavy throttle, quiet w/light throttle, needs occasional repacking). My stock pilot jet seems a bit rich right now, but other than that, my DR runs WAY better than it did with the stock main jet, the stock idle mix screw, and a KTM adjustable needle paired with this FMF exhaust and an airbox with a few small holes cut. It now idles smoothly, pulls 5th gear smoothly from 45MPH indicated, spans the wide-ratio tranny gearing MUCH better, pops the front wheel up easily in 1st and 2nd with no clutch or tugging, and pulls like a freight train with a passenger and luggage aboard...from idle to well beyond any legal speed in this country. I also still seem to be getting about 50MPG (US).:funmeterno::funmeterno: I WOULD like to swap this FMF Q2 muffler to a 2001/2002 GSX-R1000 titanium muffler, as it flows about the same but is slightly quieter, slightly lighter, and never needs repacking.

I'm now curious how powerful this thing would feel with a flatslide pumper carb, a 780cc big-bore kit, a big-valve head, a Webcams 223 cam, and a sprocket change. That would be well into 50+WHP territory, and I haven't even mentioned forced induction or nitrous yet. (Yes, there ARE a few people experimenting with that stuff, and a mfr HAS actually brought a turbo kit to market for the smaller Yamaha WR250R/X...so it COULD potentially be done. There are also a few people currently adapting/experimenting EFI on the DR.)

Google "Procycle" and "Kientech" to find performance parts and more info for your DR. They both offer a LOT of info over the phone or web.

I added a lot to mine by changing the exhaust and changing out the carb. A great resourse is Here. I spent a total of about $700 for the carb, exhaust, and midpipe required to install the GSXR exhaust.

MXRob is an expert on this. He sells the carb as a bolt on after he has done the rebuilding and modifying.

I now have a lot more useable low end power, much stronger acceleration, and no surging.

Good luck!

DR power increase
 

From the research I have done:
Stage 1: Drill the airbox 'airbox mod', re-jet the carb, grind out the header pipe weld (where it exits the engine). Pretty minimal cost, and will give you better, smoother access to the power if only marginally increasing the HP.
Stage 2: Pumper Carb modification a'la MXRob (mentioned above) and a better flowing exhaust - one or both at the same time. The '01-'02 GSXR 1000 (best) or 600/750 (still good) pipe is recommended as the top choice for performance/ weight/ noise balance. Both bolt on with an adapter mid pipe ($210).
Stage 3: Big bore and hotter cams, head work, etc. I'm sure there is 50hp in there somewhere, but personally I think pushing the DR650 this far defeats the point and takes away from what really makes this bike excel as an adventure touring option- low cost, durable, frugal, simple to fix, etc.

I just picked up a low km '08 model, have found a GSXR pipe and am planning on doing the airbox cut out and re-jetting of the stock carb. From other owners reports, that seems to yield the best bang for the buck, while still keeping the fuel economy and durability at stock levels. Great bike, I'm looking forward to setting it up for back-road touring.

this particular horse has been beaten to death 6 times over on the DR thread on ADV. i would bet a lot of dough that EVERY conceivable manner of squinching out all the power from the DR has been discussed on that thread which as of today had 59,055 posts and is been going on for over 5 years.

tons of good info and very knowledgeable folks there.

the DR650 thread - ADVrider

Brakes
 

I've dynojetted mine and done all the airbox stuff that Jesse at Keintech recommends. My problem is the brakes are so crap that I don't want it to go any faster!http://farm8.staticflickr.com/7180/6...3abacdd8b5.jpg