Freestyle Your favorite carbs and why?

[NVJAY775]

I might be a ways off from picking up some carbs / intake. I'm putting some needed money back into my business this year. So just picking up supporting parts for a build as I can. Then hopefully do a short block next year.

I'd actually like to spend some time working on jetting, mainly just to learn and get a feel for it. It'd be really sweet to just have a motor built and be dialed, out of the box, but I need to score some bucks first. So here I am, basically gathering up supporting parts and adjusting as I go. I know it's a battle, but I'm willing to put in some time.

My current set up is a freak show, but It's coming around.
I mainly ride between 4,000' and 5,000' elevation.
62t cases unmolested.
61x cyls with 64x sleeves ported by Ihavenoideawhoportedthem currently 781cc's fresh bore and pro-x pistons.
215 psi @ 5,000' elevation on 110 VP
Stock 38's with stock FA
Working on jetting now. It was golden when I had a limited b pipe and 180 psi, but compression and fuel for the pipe requires changes.
V-Force 2's
ATP Flame TL
PFP
144 mag, longer cone, 9/15 hooker, 86mm red nozzle, stock 62t turn nozzle.

The hit at CFW this last weekend was INSANE for me and I loved it, but burned a pump bearing in new solos section, starter took a dump, among other things. I felt like I would be close on a jetting change, but didn't check pop off prior to the ride, so that sucked along with all kinds of other shizznit. It basically self destructed which was a bummer, but still a sweet day at the lake. Motor is fine, hull is fine... Blablabla.

I just haven't heard of many (if any) guys running a setup close to mine as far as cc's, compression, pipe, ign, carbs, fuel and elevation to get a starting point from. So I'm sacking up and Guinea piggin it! Whatever good info I get out of it, I'll post up so others can learn from whatever I can get out of it.

 

[NVJAY775]

Thanks so much for all you guys posting up your help and experiences. Almost forgot.. LOL! Thanks again fellas.

 

[Crab]

Sounds underpropped to me...

62t cases unmolested.
61x cyls with 64x sleeves ported by Ihavenoideawhoportedthem currently 781cc's fresh bore and pro-x pistons.
215 psi @ 5,000' elevation on 110 VP
Stock 38's with stock FA
Working on jetting now. It was golden when I had a limited b pipe and 180 psi, but compression and fuel for the pipe requires changes.
V-Force 2's
ATP Flame TL
PFP
144 mag, longer cone, 9/15 hooker, 86mm red nozzle, stock 62t turn nozzle

 

[jetpilot08]

You should give Art a jingle...I heard he knows a few things about carbs and motors. :brap:

 

[Crab]

You should give Art a jingle...I heard he knows a few things about carbs and motors. :brap:

My JW modded 38's were almost spot on, just some minor screw turning...

 

[js/sj]

Black jacks will always be to rich on bottom end. Thats the only bad thing about Annual Discharge. Full spectrums are my favorite because They can be perfectly tuned all throughout the rpm spectrum. Thats how they earned the name (Full Spectrum)

 

[GIL]

Black jacks will always be to rich on bottom end. Thats the only bad thing about Annual Discharge. Full spectrums are my favorite because They can be perfectly tuned all throughout the rpm spectrum. Thats how they earned the name (Full Spectrum)

Really? How did you arrive at this mis-conception?

 

[TheBuzzard]

Black jacks will always be to rich on bottom end. Thats the only bad thing about Annual Discharge. Full spectrums are my favorite because They can be perfectly tuned all throughout the rpm spectrum. Thats how they earned the name (Full Spectrum)

nick at carbon tech said the same thing. he could never get em lean enough to lean bog on the bottom, but he was starting to like them. funny he said that and the SJ i bought from him had full specs on it and i also got a box full of blackjacks. obviously he didnt like em enough to run em.

 

[NVJAY775]

Sounds underpropped to me...

For a b pipe you are absolutely correct, as that's what I found too. I had a 10/16 and I can honestly say the 9/15 is better for my setup.

 

[lawmaster891]

saving this thread

 

[smdubs]

Black jacks will always be to rich on bottom end. Thats the only bad thing about Annual Discharge. Full spectrums are my favorite because They can be perfectly tuned all throughout the rpm spectrum. Thats how they earned the name (Full Spectrum)

Mine arent rich at bottom

Sent from my SPH-L710 using Tapatalk 2

 

[GIL]

Mine arent rich at bottom

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About once a year I find someone that says they hate BlackJacks and every time I ask them what they are running for internal parts, and every time they are trying to jet them like conventional carbs. LOL

The crazy part is-ONE PHONE CALL DOES IT ALL!!! Call Art!!!

I will say this-ANY carb that is dialed in perfectly IS a great carb.

I have run everything on the market and BlackJacks are my ONLY choice.

 

[SuperJETT]

I wouldn't say underpropped, the elevation hurts his power. Plenty of people including myself have run a 9/15 with bored nozzle on a 760+.

 

[Billybo455]

About once a year I find someone that says they hate BlackJacks and every time I ask them what they are running for internal parts, and every time they are trying to jet them like conventional carbs. LOL

The crazy part is-ONE pHONE CALL DOES IT ALL!!! Call Art!!!

I will say this-ANY carb that is dialed in perfectly IS a great carb.

I have run everything on the market and BlackJacks are my ONLY choice.

I talked to art for 45 minutes. My ski was so rich with 48 black jacks it wasn't even funny. Never got them dialed in to compare though. This summer I'll be comparing 48 black jacks, 48 atps, 49 full spec's, and 50 satos. So far my favorite is the full specs. Havent used the atps yet. But out of those and novis so far im a full spec kind of guy.

 

[tshank123]

i saw a carb chart somewhere on the web that listed the best to the worst carbs out there and why. the best were rated for ease of tuning and that was due to signal strength. there were a few brands that werent on there but novi was at the top of the heap. the best signal strength means they are kind of self tuning. you can have a jet in there thats close enough to run right. carbs with a bad signal have to be jetted dead nuts on or it runs like crap. you still have to take the carbs off 100 times to get it right,no matter what carbs you run. tuning is everything. you can have all the best parts that create big power, but it'll run like crap until its tuned right. i run novi 48s or full spec 48 & 49s usually, but in the past i have used the rest.

You're probably talking about the chart from Group K. The problem is he didn't include BlackJacks in his testing. If you've ever read Harry's articles on carbs, you know he has a negative opinion about annular discharge carbs anyway. I asked Art about that once and he told me that he didn't want to be part of the testing because it was all done without flame arrestors, which would make the BlackJacks look bad on paper. His point was, why run this testing without flame arrestors? You need flame arrestors anyway so its kinda pointless.

 

[kevbo]

You're probably talking about the chart from Group K. The problem is he didn't include BlackJacks in his testing. If you've ever read Harry's articles on carbs, you know he has a negative opinion about annular discharge carbs anyway. I asked Art about that once and he told me that he didn't want to be part of the testing because it was all done without flame arrestors, which would make the BlackJacks look bad on paper. His point was, why run this testing without flame arrestors? You need flame arrestors anyway so its kinda pointless.

GroupK did illustrate problems with most large carbs on 785 race boats. They were simply too big for the application and needed a restrictive lame arrestor to act as a choke. One reason why they work so well on freestyle boats is in tank location and acceleration. When the pipe hits you almost have fuel injection. Larger displacements and higher crankcase compression that we use now also help alot. Tuning the main circuit at zero acceleration, like on a dyno, can quickly reveal an oversize condition without the tank raised far above the engine. No carb could work under acceleration if the tank was behind them.

 

[98gti]

Black jacks will always be to rich on bottom end.

Oh, good to know that just b/c you expirienced this every single person will, I have not expirienced what you are talking about, and like Gildo said the dude can tune your carbs over the phone. So maybe you should call Art and give him your opinion on the matter, im sure he'd love to hear from you.

 

[Matt_E]

Someone tell my motor that these carbs have been running rich on the bottom for the past four years

 

[D-Roc]

Rich is safer than lean. So saying that a engine builder sends carbs out a bit rich would be an accurate statement IMO. The best tuner for carbs is the rider but most riders don't know how to tune so they assume their carbs are set the best they can be from whoever. Builders can get it close but final adj will be up to the rider for their local elevation and air temps.

 

[Scraggly]

I bought a used BJ and art gave me all the specs I needed or my setup and a phone lesson on what to look for to tune it. His spec was a bit fat but not hurting my performance really. Just had to learn how to use the carb vs. factory. I could have leaned it out some and made it a little crisper, but I liked being on the safe side as I liked to wot runs and chase barges and boats not just stay in the bay.
I never spent a dollar with him and he went above and beyond. I look forward to trying a new set on my next build.