Dynojet Needle on DR650

[tuck9mm]

This looks like another topic that has been beaten to death already, but maybe with a different question. Initially, I had my Dynojet needle in the 4th notch like the instructions said. With this setting, the bike was running terribly lean, and the problem only got worse as the rpm's increased. I raised the needle one notch (e-clip is now in the 5th notch from the top). Going down the road now, the DR seems to be at its best. It runs great and sounds much better too. But when I try to take off again after coming to a stop, it just wants to die... sometimes it does. It is really fat on the idle. I adjusted the pilot screw from 2 turns down to 1, and at least it doesn't go dead anymore, but it will still go dead if I don't burp it prior to loading it up. Does anyone else have this problem? Or should I just get used to throttling it a couple of times before letting the clutch out?

[artguy]

A few more details please. What main jet, airbox mods and exhaust are you using? What's the local altitude?

[tuck9mm]

A few more details please. What main jet, airbox mods and exhaust are you using? What's the local altitude?

DJ 155 main jet. "Jesse" airbox mod (cut out top -- side in place). Stock exhaust. Sea level.

[drdave_2006]

hi. I had the same problem with mine. Just as you are about to take off you let out the clutch a little twist of throttle and it dies a little. I did have the mixture screw out about two turns. What i ended up doing was bring the e-clip up to the next notch. I also went to one turn out on mixture like my instuctions said. That was still no good. so it is now on the top most notch. and i put in the 160 main jet just to see what it was like under heavy accel. Mixture screw is 1 1/4 turns out. It is now ok and seems to take off from a stand still how you would expect. I hope this helps you out. It has airbox mod, ground header weld, stock exhaust. Am using the DJ kit.

[svwayne]

I had same issue. Wound up with the mixture screw out ~3/4 turn and increased idle speed for a fix. I've also noticed that the bike starts a lot easier now when hot. Before the changes the motor would spin a couple of times before firing up. Now, I just touch the starter button and it's running.

[Wybs]

+1 on the idle. it should be 1500RPM. That is pretty high to my ear, but everything seems better (except the clunk when you go from N to first)

[Clear-a-Path]

Same issue...did 3 things....1. adjust the float, 2. set idle, 3. lower the needle 1/2 by going back to the 4 notch down and add the small washer that comes in the DJ kit. This will give you a "1/2 notch" adjustment. What you are getting is a mini-loadup at idle. Also if the fuel level is too high in the bowl it can suck some fuel into the main jet. I had not luck fixing the problem by adjusting the pilot screw.

2006 650, DJ 150 mian, 1 turn out on the pilot, 5300 ft elevation, airbox mod, stock exhaust. The needle clip is 3 notches down from the top with the washer between the clip and the slide (3 1/2)...runs perfect.

[IdahoJim]

DJ 155 main jet. "Jesse" airbox mod (cut out top -- side in place). Stock exhaust. Sea level.

That sounds like a pretty small main jet for sea level conditions. From what I've read, on this and other boards, you should be using at least a 160. Jesse told me to run the 150 on mine, and I'm at 4,500' elevation. Mine runs very well,and gets 52-54mpg. I'd try the 160 or 170 main with the needle in the 4th notch.

[hilltownwalsh]

I've got an open sidecover on the airbox, stock pipe, fuel screw out 2 1/4 turns, 4th from top on needle, and 160 main all at sea level. Runs very well.

[tuck9mm]

That sounds like a pretty small main jet for sea level conditions. From what I've read, on this and other boards, you should be using at least a 160. Jesse told me to run the 150 on mine, and I'm at 4,500' elevation. Mine runs very well,and gets 52-54mpg. I'd try the 160 or 170 main with the needle in the 4th notch.

I have already tried the 160 main jet with the needle on the 4th notch... it was still too lean. I think the mixture is perfect now with the 155 main and the needle clip in the 5th notch. Bumping up the idle is a good recommendation, and I'll do it as soon as it warms up enough to ride again. I just wish this thing had a tach on it so I wouldn't have to buy or borrow one.

[tuck9mm]

I had same issue. Wound up with the mixture screw out ~3/4 turn and increased idle speed for a fix. I've also noticed that the bike starts a lot easier now when hot. Before the changes the motor would spin a couple of times before firing up. Now, I just touch the starter button and it's running.

I'm about to pull my hair out now. I went back into the carb, moved the e-clip back up to the 4th notch and put the washer between the clip and the slide. So here it is at 4-1/2. Also took out the 155 main jet and put in the 160. Took the good advice and checked the float height too: it was right on 14mm, but I tweaked it up to 15mm for good measure. Result --- same problem. I am having to do exactly what you did, and put the pilot screw at about 3/4 turn and increase the idle speed... or else it goes dead when I try to pull away from a stop. Just doesn't make much sense, because I was of the understanding that you are supposed to set the pilot screw where it gives the highest idle speed, and then back off the idle setting to correct the RPMs. I'm doing it backwards -- but that's the only way it seems to work. By the way, I think the mixture was better at highway speed with the main needle in the 5th notch.

[mxrob]

I'm about to pull my hair out now. I went back into the carb, moved the e-clip back up to the 4th notch and put the washer between the clip and the slide. So here it is at 4-1/2. Also took out the 155 main jet and put in the 160. Took the good advice and checked the float height too: it was right on 14mm, but I tweaked it up to 15mm for good measure. Result --- same problem. I am having to do exactly what you did, and put the pilot screw at about 3/4 turn and increase the idle speed... or else it goes dead when I try to pull away from a stop. Just doesn't make much sense, because I was of the understanding that you are supposed to set the pilot screw where it gives the highest idle speed, and then back off the idle setting to correct the RPMs. I'm doing it backwards -- but that's the only way it seems to work. By the way, I think the mixture was better at highway speed with the main needle in the 5th notch.

Just be aware of the four stroke pilot screw and it's function. On two strokes you are controlling the air flow/vacuum applied to the pilot jet with the pilot screw from behind the throttle valve. If you close off the pilot screw pure fuel will be drawn up through the pilot jet. On a fourstroke you are adjusting the emulsion, not the air that creates the emulsion. There are two ports for the emulsion to enter the carb bore. The first one is partially or totally blocked by the butterfly valve at idle. The second is the one you have adjustment control over with the pilot screw. The more you open the screw the more emulsion you allow in. Yes, the emulsion does get richer as you open the screw but it's an emulsion so your idle speed will increase. The next dilema is when you start to open the throttle... now the rich mixture you've created by cranking open the pilot screw is only multiplied by the butterfly valve moving away from the second port. The extra velocity/vacuum will draw even more fuel up from the float bowl once this port opens at partial throttle. I suggest attacking it from a different angle. Turn the pilot screw in and if the idle drops crank the idle up a bit. There will be a point that the engine will idle erratic... you know, like it did with the factory settings. Now, as you open the pilot screw to smooth out the idle turn down the idle to keep the engine at the same rpm. You'll hear that nice even thump thump. Staying closer to the leaner side of a good mixture on the pilot circuit is your best bet IMHO. I expect my properly tuned DR to lean surge slightly at partial throttle when the bike is not fully warmed up... and that's exactly what it does. But it runs smooth without a hickup once she's warm. To tell you the truth I think the DJ needle is too rich at the 4th clip position at sea level. I'm running mine on the 3rd position. Because the needle is so short the clip movements affect partial throttle more than they affect the upper throttle ranges.

[bgrzdr]

I am in agreement with the previous post. the trouble you are having off idle is rich, not lean. I too am running in the 3rd notch at close to sea level with a 150 mik main, screw about 1 1/2 out. DJ needle has such a steep taper that moving it a little can drastically affect off idle and low speed mixture.

[beatpusher]

Possible dumb question here: My instructions say "Place clip in groove #2 from top"

Are you guys counting from the top down in your suggestions?

My problem seams to be the exact oposite of what is stated above. At highway speed (60mph) I give it gas and the motor cuts out, almost sounds like I'm hitting limiter.

[IdahoJim]

Possible dumb question here: My instructions say "Place clip in groove #2 from top"

Are you guys counting from the top down in your suggestions?

My problem seams to be the exact oposite of what is stated above. At highway speed (60mph) I give it gas and the motor cuts out, almost sounds like I'm hitting limiter.

I just reread my instructions. It definitely says to place the clip in the 4th groove from the top. Are you sure about the brand of kit you have? I'm a little confused by those instructions. Here's the "pasted-in" copy from my instructions:

2. Install the Dynojet needle on groove #4 from the top. OMIT the white

nylon spacer (Fig. A). Install the small Dynojet washer above the e-clip.

After installing the slide in the carb be sure to check slide movement

manually.

[beatpusher]

oof!

Just relized this was a thread about the 650. Wrong bike! /me sticks foot in mouth.

[Gary7]

I'm having the exact same problem. My specs:

Elevation: 5300 feet; Air-box top cut out; Stock air filter; Supertrapp IDS2 quiet core, 10 disks installed; DJ160 main; Clip in 4th notch from the top, washer between clip and spring ring; Idle screw: tried at 2.5 out, now at 1 turn out (maybe a slight improvement over 2.5).

As soon as I just touch the throttle it'll die if it's cold. Warm it'll also die, but I can feather it a bit and keep it from dieing. Once the throttle's open she runs like a champ, and it idles fine, although I need to attach a tach to make sure it's high enough.

I'll try some of the suggestions mentioned here and see what happens.

Gary

[R_Little]

I have a similar issue but it only happens if I leave the motor idling for a while like at a stop light.

Remember the recommended idle is 1500 rpms which sounds is rather high. most folks set the idle to 1000rpm and get this problem.

[mxrob]

I have a similar issue but it only happens if I leave the motor idling for a while like at a stop light.

Remember the recommended idle is 1500 rpms which sounds is rather high. most folks set the idle to 1000rpm and get this problem.

That is a classic sign of rich load up. If it were lean no matter how long you idled it would not change.

[IdahoJim]

I'm having the exact same problem. My specs:

Elevation: 5300 feet; Air-box top cut out; Stock air filter; Supertrapp IDS2 quiet core, 10 disks installed; DJ160 main; Clip in 4th notch from the top, washer between clip and spring ring; Idle screw: tried at 2.5 out, now at 1 turn out (maybe a slight improvement over 2.5).

Gary

I think you're too rich on the mainjet Gary. I'm slightly lower than you, and running the DJ150, though I'm going to try the 155 next. With the 150 it runs great. The clip is in the 3rd notch from the top ( I think this is important on the just-off-idle problem). I have Jesse's extended idle screw and it is set about 1 turn +/-. I'm running the stock pipe, and have the airbox top modded as per Jesse. I'm really starting to think the clip position is critical. The main should only have a large effect at 70%+ throttle position. From about 1/4 throttle up to 65-70% that clip position really controls the mixture. I'm getting reports, even from guys at sea level, that the 3rd notch is better than what DJ says in the instructions.