• Welcome to the Two Wheeled Texans community! Feel free to hang out and lurk as long as you like. However, we would like to encourage you to register so that you can join the community and use the numerous features on the site. After registering, don't forget to post up an introduction!

Dr650 Dynojet Install

Forums New posts
cmattfish

cmattfish

0
Joined
Apr 29, 2008
Messages
107
Reaction score
1
Location
spring branch
First Name
matt
Last Name
geiger
Does anyone have experience installing a Dynojet kit on a dr650? I have not opened the carberator yet. Instructions on the kit make it look easy but you know how that goes. Any help would be appreciated.
 
Haven't done the Dyno Jet kit on any of my bikes, but as far as installation goes, they're all pretty much the same, and not difficult. The hard part is picking the right jet size and needle position. I would suggest starting with the stock jet size and work with the needle clip position first. It will likely have you drill the slide too, and they usually include the right bit.

Just be careful with the rubber diaphragm when reinstalling it, and make sure it's seated right.
 
Mudshark helped me install a jet kit on mine. Well, ok, I helped him install it. I'd already dropped a bunch of weight off the rear subframe with a Supertrapp, and without any intake mods, it was running pretty rough.

Talked to Jesse Kientz at Kientech and he hooked me up with the jet & needle kit, as well as an extended idle mixture screw to make tuning a LOT easier (no fumbling to get a tool on a hidden/recessed screw anymore).
http://www.kientech.com
He's also got some decent diagrams for opening up the airbox.

By the time we got done rejetting, shimming the needle and opening up the airbox, the DR was like a whole new animal. Unfortunately, that was the same day a lady pulled her Mercedes out in front of it.
 
The instruction says main jet #160 for stock and #170 for hi-flow exhaust, but #155 worked better for me with stock pipe and #160 with supertrapp.
Both tested with air box mod and K&N filter on sea level.

Increasing slow jet size also worked a lot better in my case even though Dynojet not recommended.

Ken
 
cmattfish said:
Does anyone have experience installing a Dynojet kit on a dr650? I have not opened the carberator yet. Instructions on the kit make it look easy but you know how that goes. Any help would be appreciated.
Click to expand...

We just did my DR this weekend with help from ED29 and DFWarrior. It was easy but not without problems. We had factory screws that felt like they were welded on with soft heads. We had to use an easy out on one. I would get a set of hex screws ahead of time to replace them with. I still need to fine tune. I have a surge at wide open. BTW, my bike is stock. It would backfire when I let off the gas.
 
Like FJR Bandit said, The four screws holding the float bowl on the carburetor are very tight and/or Suzuki used lock-tight. Either way, the screws are soft and you will probably damage the slot (which is some Japanese version not exactly like a phillips head). Some DR650 owners have reported good results using an impact driver. You probably should have new screws on hand. Kientech sells a set specifically for this purpose. Personally, I opted for the Mikuni TM40 from Procycle, and put the stock CV carb on a shelf with the other take offs. It wasn't the economical option, but it runs much better with the flat slide carb.

You'll find lots of information about carburetor tuning for the DR650 in the DR650 forum threads of ThumperTalk and ADVrider. Some people have problems with the Dynojet install/tuning, but most report an improvement in tractability and reduced surging. Good Luck cmattfish.
 
Thanks for the input guys. I might get into it this weekend. I will be looking for screws this week.
 
cmattfish said:
Thanks for the input guys. I might get into it this weekend. I will be looking for screws this week.
Click to expand...

I just ordered my hex head screws from Jesse at http://www.kientech.com along with with his extended air/fuel screw and some other items. Jesse was a very easy guy to talk with, full of information about the DR. :clap: :clap: No doubt, I'll be ordering more from him and the credit card :giveup: :lol2:
 
I am positive that a lot of DR650 screws are made of butter. So getting new hex screws from Jesse is a great idea. In fact, I ended up using them on top of the carb as opposed to bottom (which you need to take off if you are changing the main jet - I ended up just shimming my stock needle). Because... well... the top screws are made out of butter too...

I do think that those screws can be found at Ace Hardware though, just an FYI if in a pinch.
 
I have an 06 650 stock. I want to do the dyno jet mod but keep the oem muffler. Any advice on what other changes to make to get the jet kit to work?
Such as air box open up, backfire screen out, grind header pipe. Now much is too much with stock muffler?
 
Jeff,

It's been awhile since I paid attention to the Dynojet install issues on a DR 650, but all of the things you mentioned, especially opening up the air box should have a positive effect. As I understand it, the air box is the most restrictive aspect on a DR. Folks that have done the work (including MX Rob on Thumper Talk) report that while the OEM muffler is heavy, it is not overly restrictive. Many people that originally installed the Dynojet kit with an aftermarket muffler have gone back to the OEM muffler after becoming tired of the noise and/or re-packing chores.
I think the setup instructions provided by Dynojet may include an option to retain the OEM muffler. It seems that the settings recommended by Dynojet typically run a little rich, so you will probably want to start on the small end of the recommended range. Perhaps someone else here can help with the specific sizes of the jets.
 
cmattfish said:
Thanks for the input guys. I might get into it this weekend. I will be looking for screws this week.
Click to expand...

well I just got around to installing the Dyno Jet Kit (160 jet). Along with a FMF header and FMF Q4 exhaust with an air box mod. It runs great up to around 50-60 mph and then it stumbbles. :doh: Any ideas on how to get rid of that? I dont know what to adjust because it runs so good up to that pointthanks in advance
 
Smaller main jet and drop the needle.. Dynojet recommendations are notoriously rich IMHO.
 
if i reduce the jet and lower the needle that would decrease fuel flow but alow it to flow better under load?
 
It would reduce the fuel flow. It sounds like the main circuit is off, which is controlled by the main jet. The needle controls the mid-range circuit. There is a significant overlap from about 2/3 throttle and full throttle. You need to decide where it is bogging and if it is a rich or lean condition. Looking at the spark plugs should tell you a lot as will the smell of unburned gas. My guess is rich just based on my experience with dynajet.
 
kurt said:
Smaller main jet and drop the needle.. Dynojet recommendations are notoriously rich IMHO.
Click to expand...

i just finished putting it back the way I had it. I could not get it to idle at all. So i put it back together and it still does not idle off choke. I also noticed a small oring on my bench that probably should be in the carb:doh: so tomorrow i need to get back into it and figure this out. Friday i need an inspection
 
Many carbs have an o-ring between the cap and the carb. Not the carb same as yours, but same idea.

26cutoff.jpg
 
The way I check if it is lean or rich on the main is get it up to speed where you notice the surging, then open the choke. That will make is somewhat richer and if it gets better you were lean. If the same or worse, then you were rich. Or warm it up, then take off the side airbox cover and go for a ride. That does the opposite. Lets in more air and leans it out. If it is better with the cover off you were rich. Worse, you were lean.

And yes, the o-ring could have been a problem.
 
You must log in or register to reply here.
Back
Top