The Mighty DR650

I’m interested in your project (as others will be if it’s easy, compact, and affordable) as i own a suzuki DR650. Suzuki has kept this bike carbureted since it’s inception. It needs fuel injection.

The bike has more or less negligible changes throughout it’s history, my specific model is the K5 (2005) model.

Personally, if i can contribute, i’d like to. I have a clean bike with low-ish miles (15k), i’m a competent mechanic, a middling programmer, and a functional TIG welder. I’m more intimidated by a lack of electronics in a motorized vehicle than the work to swap them in.

Current options for my platform are the ecotrons setup and some hacks from various suzuki quads. None of these are a particularly good fit, though they can be shoehorned in. I’d like to think nanoEFI might do better.

1 Like

Welcome @takophiliac ! :wave:

We’ve seen a lot of interest in NanoEFI from the DR650 community. I’m looking forward to seeing the first install!

If you don’t mind, would you be able to upload a few screenshots of the manual for the K5 model? In specific, the pages regarding your electrical specs and diagram would be great. Thanks!

I’ll do several better. I’ve got the 96-05 manual with addendums for model years, i’ll upload shots of all the wiring diagrams, as well as electrical related specs pages.

1 Like

Here’s a link to a photos album. Let me know if it’s preferable to have the images uploaded to the forum directly.

1 Like

Nice work with the diagrams.
I might have to do the same for my xr400.

I briefly thought about cutting them out and using a bed scanner, but only briefly. I may yet just to get the book in digital form.

1 Like

Dude, so harsh. Someone had to do the first DR650 EFI project. I had limited stuff to work with 10 years ago. :wink: Besides I don’t think anything about my project was hacked… of course YMMV. :slightly_smiling_face:

1 Like

I meant no disrespect.
I intended for people who were aware to know what it was, and people not aware to not be unduly intimidated.
I say “hack” with the highest possible level of respect. I was already shopping for hack parts before i stumbled on nanoEFI because ecotrons price doesn’t seem to add up.
Your write-ups are inspirational to say the least.


No worries… just chiding you a bit. Things have come a long way since I forged through my project. It’s going to be a lot easier to build a system now. After seeing the improvements that taking over the ignition made on my machine I would never consider just a fueling option setup like the Ecotrons… but I did give it a shot just to see. My setup was superior to the Ecotrons system.


1 Like

Hello, Sadly I have little to add although I will make up for it with enthusiasm…


Welcome @onlydad! :wave:

1 Like

Bike finally all back together after cleaning up some of the PO problems and factory mistakes, like the PO breaking off the upper chain roller



Not my proudest welding, but i had some problems due to the welding helmet sensor being blocked by a shadow from the frame, which i tried to weld blind a couple times, which was a terrible mistake. Eventually i found a position i could weld in reliably, and then fixed most of the rest in post (grinding) The paint job is terrible also, but it’s in a nearly invisible part of the bike, so, good enough for the ladies I date.

Of course, one of the PO problems was that they didn’t have a fuel filter on it, likely due to the tank on the bike having the petcock so close to the float bowl inlet that most filters don’t fit without a big loop of hose.
Of course, due to this, a bit of something had gotten into the carb and was sitting in the pilot circuit (it came out with the pilot jet) making the bike run like crap without the choke on.

Next up i need to do some reading and tuning as the bike has a supposedly brand new (seemed brand new when i took it apart) supposedly stock (though, the intake boot and airbox say 32e0 and the carb is marked 32e1) the engine is hesitant in the bottom 1/4 of throttle. I’ve opened up the pilot circuit another 2 turns (from 1.5, total of 3.5) to get rid of decel popping, idle wheezing and get it ride-able, but there’s still the general impression that if you’re on decel and you crack the throttle, it feels like it’s got roughly no effect for about 5-8% of throttle.
Whacking the throttle open causes perhaps 75-150ms of hesitation before it starts ramping up power.

For reference, I’ve also set the idle to 25hz (1500/m) using a clamp-on meter around the spark plug wire.

I’ve also plasti-dipped all the white parts of the bike blue, so obligatory full bike photo to put a machine to the project.


:rofl: :rofl:

A standard as true and old as time.

Looks great!

Any chance there might be an intake leak at the boot? Sounds like a little more air is getting in after the carb than should be.

This was my thought as well, but i’m not seeing anything. Research i’ve done today indicates that this may either be normal (for emissions, apparently the jet needle is a bit of a fat profile near the tip, also possibly the slide not having enough balancing port) or due to a clogged slide breather filter (which causes the slide to move more slowly due to slowed pressure equalization.) Some have also indicated that where the slide breather is facing relative to the airbox opening may have an effect.

There will be more fiddling soon.

Of course this would be a simple thing to identify and fix were it not a carb :wink: For the sake of EFI tuning, i hope it’s just a clogged secondary breather. Trying to not modify the stock fuel system beyond factory config too much before the conversion.

Actually, the boot may be loose or otherwise damaged. I noticed i could twist the carb in the bike fairly easily. I could still twist it after tightening the intake boot to the point that the clamp was at it’s minimum circumference.

So… a new boot and clamp are in order, i spose. We’ll see how it goes.

1 Like

Sounds about right. Intake leaks can be a real pain. A trick I’ve used often is to hold an slightly open (just a crack) but unlit propane torch against suspect areas of the intake, listening for idle quality to change in response. Works well when done right. But I dunno, I stopped recommending anything potentially flammable a while ago 'cause people do all kinds of weird stuff you wouldn’t expect :boom:

So you didn’t hear that from me :sweat_smile:

I’m curious what is turns out to be, keep us posted!

1 Like

I will definitely update, but i think i will also definitely play with fire! :fire:
That’s so simple, it’s a wonder it wasn’t obvious.

In a long round about fashion, I ultimately added an AEM UEGO kit to the bike to nail down troubleshooting, and ultimately identified that a big part of the problem was that the air filter wasn’t restrictive enough, mostly because it wasn’t oiled nearly enough.
Increasing intake resistance hasn’t completely solved the engine, but it has made it safely drivable.
Of course, nobody would want to increase resistance for tuning, but carburetors depend on a certain level of resistance to work.

Well, that would have had me stumped.

It is a bit of a pain. It’s as though suzuki doesn’t want the carburetor to work right, frankly. Or rather, in order to pass emissions, it can’t work “right”. Maybe there’s a timing thing, maybe there’s a regulations thing. It’s surprising that they didn’t put the TM40 on it to start with.
I can say, having owned a couple of suzuki bikes, they have taken pains on some models (like the DL1000) to not make the throttle snappy from open. So maybe it’s a suzuki “brand feature”. The DL1000 actually has secondary throttle plates that are computer controlled which operate on a ramp based on RPM and load. You can pull the throttle full open, but the secondary throttles won’t become full open for a second or so after intentionally. Or perhaps this is done to simplify fueling calculations by making the system work more like a CV carb. The world may never know.