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Mechano
3rd February 2005, 12:42
I've mounted the Screaming Eagle Dynojet kit on my '04 XL1200C togheter with a teardrop S&S style AC for CV carb.
I was searching for a 45 pilot jet but the dynojet kit instructions say to use the stock 42 with an air screew position of 3,5 turns out.

The Screeming Eagle Dynojet kit is produced by Dynojet but with Harley Screaming Eagle brand. Outside it there's written 96-up FX-XL. It's not for XL models only.
Into the instructions there's explicit referring to the XL '04-up models where it's not necessary to mount some of the hardware provided into the kit (something related with the float bowl and its fuel hoose.

There's an emulsion tube and lot of jets from 160 to 200 with 10 points steps.
The Dynojet emulsion tube is a bit different from the stock one. It puts the main jet at a different position.
Maybe the reason is because the keihin jets and Dynojet jets are different. The hole is in a different position, and there's a different flowing cone inside on both side.
If I use a Dinojet jet on stock emulsion tube the jet hole results few millimeters under the fuel level.

Another important difference between the stock emulsion tube and the Dynojet one is the holes number and positions. The Dynojet tube has only 2 small holes in the lower side. The stock tube has many more disposed for the whole length.

Into my bike I've found stock a 160 main jet and 42 pilot. So I've changed the 160 with the 170 provided by the kit togheter with the emulsion tube.
Left stock the pilot jet and turned the air screew 3,5 turns out.

After warming with the teardrop AC and it's good air flow the idleing has a rich mixture, I can see a bit of black smoke and I feel that particular richness sent of the exhaust gases.
I can also close the choke when the engine is still cold and the engine has some hesitations but doesn't turn off, I was not able to reduce or close chocke before mount the Dynojet kit.

I went to visit a friend of mine who sell car exhausts and we checked with his instruments, and I was right, rich mixture.

Now I've closed 1/2 turn the air screew (going to 3 turns out) and trying, it seems a bit better but I think it's still a bit rich.

The emulsion tube is an important component for providing the right mixture emulsion.
The better is emulsionated the mixture the better it burns and delivers power. So I don't understand why this Dynojet tube has so little holes.

I still don't know if the mileage is better or at almost the same. From it depends lot of the mods I'm going to do to this carburetor. The purpose is good power delivery at acceptable mileage.

And this kit seems not well fine tuned...

stevo
3rd February 2005, 13:11
You've answered your own questions...

The stock emulsion tube is fine and as you've said more holes and better fuel dispertion..

I personally think the "kits" are a load of crap...

The stock carb set up can be tuned well to suit most applications..

To give you an example my 1200S carb is still runnin stock main and stock spring...up 1 - 2 to 45 to 48 depending on where I'm running the bike but normally 48 and 1 3/4 turns out
The slide hole has only been drilled to 2 number drill sizes over stock... no where near the 1/8" recomended on some of the kits.

This carb has run my bike to 11 second 1/4's
It has also been in many different bikes including a sporty with a sidecar, twin cams, sporties and a 1500 Suzuki Intruder...

This carb was damn near perfect in the jetting for ALL these different applications..

I have a box full of carbies which are no good because people have drilled out holes oversize.....

THERE'S NOTHING WRONG WITH THE STOCK CARB that a little fine tuning to remove the restrictions placed by the EPA wont fix...

Mechano
3rd February 2005, 14:11
You've answered your own questions...

The stock emulsion tube is fine and as you've said more holes and better fuel dispertion..
I personally think the "kits" are a load of crap...
The stock carb set up can be tuned well to suit most applications..
To give you an example my 1200S carb is still runnin stock main and stock spring...up 1 - 2 to 45 to 48 depending on where I'm running the bike but normally 48 and 1 3/4 turns out
The slide hole has only been drilled to 2 number drill sizes over stock... no where near the 1/8" recomended on some of the kits.
This carb has run my bike to 11 second 1/4's
It has also been in many different bikes including a sporty with a sidecar, twin cams, sporties and a 1500 Suzuki Intruder...
This carb was damn near perfect in the jetting for ALL these different applications..
I have a box full of carbies which are no good because people have drilled out holes oversize.....
THERE'S NOTHING WRONG WITH THE STOCK CARB that a little fine tuning to remove the restrictions placed by the EPA wont fix...

I knew that for lot of bikes the Dynojet kit was useless. But I though also that Harleys are out and globally not revolutionated from long, so there's been time for fine perfection of this kits.
This Dynojet didn't cost too much because I had into the bike's price.

When I had both Dynojet and Keihin needles into my hand waited a while before mount the DJ, took a centesimal metric cursor caliper and put togheter taking the diameter size of the needle. Taking the size from top to down in the same position from the head sit I saw that the Dynojet has the same taper design than the stock one except that it's diameter is near 1/10mm smaller than the Keihin needle, and it's near 1-1.5mm shorter.
What does it means? That you can have the same results simply rising the stock needle of near 1-1.5mm. Because the taper size will be reduced near the same of the DJ at every needle height and you put the tip a bit away from the main jet just to provide a bit more carburant at lower revs.

I also enlarged the vacuum hole in the slider, but I didn't do with the 029 drill provided in the kit, but I preferred to use a 3mm metrical drill, it's slightly thinner.

If you have some broken CVs because of too large hole drilling, sell one to me. I'm able to repair. Using strong metal epoxy glue and redrilling with the right diameter...

I think I'll search for the Keihin 45 pilot and 170 main (I've found 42/160 stock). I'll try to understand if this Dynojet needle can be usefull, and doing fine tuning of the stock spring too.
If the raised stock needle gives the same performance of the DJ, I'll go to sell this kit...

I'm able to shorten the stock spring in a reversable way so I can go back if something goes wrong. I use tin soldering for shorten.
Shortening is the way to anticipate the slider rising.

stevo
3rd February 2005, 14:29
I have found thru practical application that for over 95% of HD's

all that is needed for best performance is to remove the restrctions that were placed on the engineers by the EPA

this is typically in the up to 3000 RPM area..

I've found it is RARE that the main jet needs to be changed.

The area affected by the EPA is usually reversed by increasing the pilot jet size ny 1 - 2 sizes and often raising the needle by up to 0.040" ... normally 0.020" is enuff.



At the end of the day you are not riding the carburetor... you are riding the bike..

The carby does nothing more than meter the fuel... so if you can get it to meter it correctly then that is that job done....... next area..

It is adjustable to allow for fine tuning due to atmospherc conditions particular to where the bike is...

Changing things just for the sake of changing them achieves nothing...

Things should only be changed to achieve a particular goal..... if that goal is to brag to your mates that you have a BIG carby or that your carb has a "KIT" in it, then so be it...

I am interested in nothing more than a sweet running bike that has the time cards to say it runs fast..... and I wish to acheive that with the least amount of effort and $$$$$

Turbota
3rd February 2005, 15:06
Stevo makes a point ... The carb can be made to run very good with stock parts.

But, since you have the same DynoJet kit I have, there are a few things you can do if you want to use it.

You just have the older kit, but the needle and emulsion tube are the same # as the new kit made specifically for the 04-05 Sporties.

In the new instructions for the 04-05 1200, they will tell you to install the little C clip on the 4th groove from the top on the needle ... not the 3rd.

Remember, the 3 little washers go on top of the C clip, not below the clip.

Use the 170 main jet. (it's smaller than the stock main jet that came out of the carb, but you now have a thinner needle, so the combination of the 170 jet and the thinner DynoJet needle will work good together)

Go buy a 45 slow jet and turn the idle mixture screw 2 1/2 turns out.

I found that using the stock slide spring worked better than the light DynoJet spring. The DynoJet spring would cause hesitation because it allows the slide to open too fast and the carb looses it's Constant Velocity. In fact, the new instructions tell you that the stock slide spring may be needed to be used.

As per your instructions; Don't worry about the small parts that are not used on the 04 models. They are for modifying the accelerator pump. Not needed on your carb.

Good luck ... If you put the bike on the dyno, they can check your air/fuel ratio, and you can make slight adjustments then if needed.

Ron,

jwb47
3rd February 2005, 15:10
I just installed the screamin eagle dyno-jet kit exactly as the instructions described 170 main drilled the slide used there needle clip on the third slot 3 washers but I only adjusted the idle out 2.5 turns so far so good . it fixed the coughing and farting and warms up alot better. I also used there spring . I also installed a hyper-charger at the same time. seat of the pants it feels like I gained some , not much but I can tell a difference . maybe its just the joy of installing parts on my bike and it actually started and run lol :clap
oh yea my bike is a 1200r 2004

Mechano
3rd February 2005, 15:27
Stevo makes a point ... The carb can be made to run very good with stock parts.
But, since you have the same DynoJet kit I have, there are a few things you can do if you want to use it.
You just have the older kit, but the needle and emulsion tube are the same # as the new kit made specifically for the 04-05 Sporties.
In the new instructions for the 04-05 1200, they will tell you to install the little C clip on the 4th groove from the top on the needle ... not the 3rd.
Remember, the 3 little washers go on top of the C clip, not below the clip.
Use the 170 main jet. (it's smaller than the stock main jet that came out of the carb, but you now have a thinner needle, so the combination of the 170 jet and the thinner DynoJet needle will work good together)
Go buy a 45 slow jet and turn the idle mixture screw 2 1/2 turns out.
I found that using the stock slide spring worked better than the light DynoJet spring. The DynoJet spring would cause hesitation because it allows the slide to open too fast and the carb looses it's Constant Velocity. In fact, the new instructions tell you that the stock slide spring may be needed to be used.
As per your instructions; Don't worry about the small parts that are not used on the 04 models. They are for modifying the accelerator pump. Not needed on your carb.
Good luck ... If you put the bike on the dyno, they can check your air/fuel ratio, and you can make slight adjustments then if needed.
Ron,

On my european '04 XL1200C I've found a 160 main jet.
Yes I'm going to search for a 45 pilot. If I don't find at the moment I can find a smaller one and get drilled with calibrated drill from a friend of mine who work on old cars restoration and old carb tuning. Till I'll receive the keihin original 45. A drilled jet works well, but an original one I can be sure has been flowed for that size.

I want to find a 170 keihin jet. The one provided with the Dynojet kit is different, They seem Mikuni jets, but I compared with some Mikuni I have and they are different too.
The cone inside, and the hole position are lot different from Keihin jets. Expecially the hole position into the jet results in a different deepness from the fuel level into the bowl.

The new 04-05 Sportster's kit needle, to put on 4th position from top, has the same part number/code of the old kit (the one I own)?

I know the whashers go on top, they are for needle stabilizing, putting under they'll rise abnormally the needle.

Ok now I've all the necessary infos for a fine tuning...
I'll use them like a good starting point for my personal CV mods.

Thanks!

Turbota
3rd February 2005, 15:54
Here is a link for the new 04-05 DynoJet kit with install instructions and part numbers.

http://www.dynojet.com/pdf/8135.pdf

Like I said, the needle and emulsion tube are the same as in your older kit.

Mechano
3rd February 2005, 17:33
Here is a link for the new 04-05 DynoJet kit with install instructions and part numbers.

http://www.dynojet.com/pdf/8135.pdf

Like I said, the needle and emulsion tube are the same as in your older kit.

Thanks.

Ok I've found another 42 and got drilled to 45. And an original Keihin 170.
I'll put back the original emulsion tube and I'll try different setup of the needle both the stock and the Dynojet.

Mechano
4th February 2005, 18:28
Back from my tests.

There's lot of important things I've seen...

At first I've to say that the first time I didn't mount the Dynojet needle very well. I didn't see that the needle hole in the slider is smaller than the dynojet needle, so it didn't enter perfectly resting lot rised and leaving the mixture too rich. But with this strange setup I've seen how strong the bike pulled. There was black smoke from the exaust but I had no hesitations during the transition from the mid range to the high revs. A very poor mileage too.

Now I've put 45 pilot (2,5 turns out air screew) and 170 main, Dynojet needle with clip in 4th position (from top) with the stock emulsion tube. And yes now I've drilled a bit the needle hole so the DJ needle can sit right and don't rest rised.
Notice that the stock jets are different from DJ and new Keihin jets. They are bigger outer diameter and don't screew on DJ emulsion tube like a new Keihin or Dynojet jet doesn't screew on stock emulsion tube. Those are "old" 1986-1996 Keihin jets.

With the stock emulsion tube there's not that strong pull I had with the DJ emulsion tube and raised needle. But I have to say that fuel mileage is really better.

The emulsion tube is really important to correct mid range. So I think I'll buy a second stock and modify to find a situation that is between the too rich Dynojet emulsion tube and the stock one.
I'll close some holes with an epoxy dual component glue.

But before I want to try some others needle raised positions.