99 heritage carb tuning?

[harleytq]

Got a pretty much stock EVO heritage, just air cleaner, mufflers and the dyna jet carb kit. I heard something about the dyna jet kit not being very good, should I go back to stock? What should I run in it for jetting?

[twincam8888]

How does the bike run now? Dyna jet kit is ok. Thunder slide kits suck, in my opinion.

[harleytq]

lots of decell popping and coughing through carb when you back off and roll the throttle back on. also when its cooler out it seems worse. rear muffler is blued pretty good.

[twincam8888]

Might be lean. I would look for an intake manifold leak first.

[nibroc]

I put up with the coughing and popping on my 99 FLSTC---am cheap and like the mileage it gets--bought a sportster needle years ago (2000) but never put it on --yet

[harleytq]

Just replaced the intake seals, old ones didn't look bad at all.

What is the sportster needle suppose to do? I probably wouldn't want to use that with the dyna jet kit, would I?
What is the part number for it? Is that all you are suppose to do is change that needle and thats it?

[tomfiii]

Dyna jet just firehoses the gas in to overcome lean condition. Do you know what parts of the dyna jet was used and your current jet sizes?

[FLTRI]

Return the carb to stock with the sportster needle or .040-.050 shim under the stock needle.
Caution: be sure to use washer(s) with a small outer diameter that will fit into the indentation in the slide.
No need to change the main jet
One size up from stock on the pilot jet. Ie: if stock is 44 put in a 46.
Unless you have an intake leak or something else that causes lean running, this setup has been tried and true for stage1 EVOs.
Let us know,
Bob

[twincam8888]

Return the carb to stock with the sportster needle or .040-.050 shim under the stock needle.
Caution: be sure to use washer(s) with a small outer diameter that will fit into the indentation in the slide.
No need to change the main jet
One size up from stock on the pilot jet. Ie: if stock is 44 put in a 46.
Unless you have an intake leak or something else that causes lean running, this setup has been tried and true for stage1 EVOs.
Let us know,
Bob

I agree the above is tried and true (usually the slow jet was a 42 and a 45 from Harley or a 46 from Drag specialties was a good change)

[Bruno-Katz Fokkerpilot]

Replace it with a Mikuni 42 

[nibroc]

Replace it with a Mikuni 42 

    has nothing to do with the original question

[mr. pitts]

Sportster needle, 45 mid & 190 main jets (keihin) are a good place to start. Check the slide rubber for holes/rips/tears.

[Hossamania]

And check the accelerator pump and spring.

[dcstrng]

I’m up one size on the pilot (with EZ-just) and after slip-ons and the Arlen Ness intake went up two on the mid, partly to control head-temps in prolonged summer stop and go – Sportster needle got rid of most of the roll-on stumble… I agree with earlier, unless there have been exhaust/intake tweaks, I’d stay with stock (maybe add the EZ-just) and go to the Sportser needle (thought I read somewhere that it was no longer available -- J&P or somewhere).  Anyway, after some fiddly-diddly puttering with my setup a several years back, I’m happy with mine and haven't touched it since…

[Wide Glide]

I had issues with my CV carb last year and used the jet kit from http://www.cv-performance.com/
and straight it right out. There is tech forum on the site that is a great resource.

'97 FXDWG
Mike

[harleytq]

Dyna jet just firehoses the gas in to overcome lean condition. Do you know what parts of the dyna jet was used and your current jet sizes?

Well I cant remember exactly, but I think we drilled the hole bigger in the bottom of the slide, so I suppose I would need a new one of them? will have to look at the kit again, been a long time since we did that. But anyway I have all the other parts we took out.
Can you still get the slide from harley?

[Hossamania]

I'm pretty sure the slides are still available.

[harleytq]

Return the carb to stock with the sportster needle or .040-.050 shim under the stock needle.
Caution: be sure to use washer(s) with a small outer diameter that will fit into the indentation in the slide.
No need to change the main jet
One size up from stock on the pilot jet. Ie: if stock is 44 put in a 46.
Unless you have an intake leak or something else that causes lean running, this setup has been tried and true for stage1 EVOs.
Let us know,
Bob

where do I put the clip on the needle, If I use the stock needle? and where if I use the sportster needle? What year sportster needle do I need? Is it still available?

[Hossamania]

Stock needles do not have a clip. They are a fixed position needle, same with the sportster needle. Your needle was part of the kit that was installed, and you could probably re-use that. Set the clip in the middle, and you can tune it richer or leaner from there. Lowering the clip will richen your mixture by raising the needle out of the jet, allowing more fuel to enter. Raising the clip will lean the mixture, putting the needle deeper into the jet, restricting fuel flow.
What happens with the sportster needle is that it has a more slender taper than stock, allowing a little more fuel to slip past. Your adjustable needle can be made to do the same thing, with even more settings than the fixed setting of a stock type needle.

[Hossamania]

I'm pretty sure the stock pilot jet size is a 42. Putting in a 45 has usually been a pretty good mod. Also, the idle mixture screw has a cap covering it, and yours has most likely had the cap removed so that it can be adjusted, maybe 2 1/2 turns out. The stock main jet is a 160 I think, a good start is to change that to a 170.

[nibroc]

   Hoss describes it pretty well     

[harleytq]

Yes it was a 42 pilot jet, looks like I must have bought a 45 and installed that when I did the kit, not sure about the stock  main jet, for some reason I dont have it in the kit. are the dynojet main jets the same as keihen jets? they gave me a selection in the kit, I think I'm running 180 now. They had me drill the slide with a #29 drill bit. also gave me a new accelerator pump nozzle, check ball and weight. not sure what I did with the stock ball and weight. Might have to see if I can get a carb on ebay cheap, that slide is $48 ?
Is this the right part # for the sportster needle?  27094-88  # N65C

[Hossamania]

If you do get a carb, try to get one that is unmolested. The slide is a bit pricey, bit the rubber diaphragm is fresh, who knows how the rubber is on a used carb, may end up needing a slide anyway.
N65c is the needle, some have used an N72s also, I think. Not sure on that one.

[mr. pitts]

Someone correct me if I'm wrong, but with the dyno jet kit, you get an emulsion tube which only accepts their jets. They have a different thread to the keihin jets. Drilling the slide lets it rise faster, which can lead to a weak mixture in midrange. There's a video on you tube entitled "Harley cv carb mod" which might help you along. HTH.

[92Fatty]

I'd recommend open it up and see what you have. I set my carb up from the nightrider carb tech. I run 45 with a 180 main jet. I am using the Sportster needle with no shims. I also drilled the slide but used one size smaller bit John S recommended 7/64. It runs like a champ with Longshots exhaust. I regularly get 45mpg.