Topic: Air Filter & Stack Filter Kit for 550's & 750's / The end, see post #898, pg 36

[Tintop]

Megaflow is what ITG call this series / style of filter.  How about the 'SOHC Deep Breather'.

[Flying J]

how about,   Soichi-Flow.

[shizzomynizzo]

Yep, looks good, but I'm not sure if I like the idea of using a set screw to secure the alloy "connectors" (not stacks, so performance will be questionable) to the carbs, and there's no mention of what filter (if any) is used? Another option though, which is always a good thing. Cheers, Terry. 

I've contacted him in the past, it's uni material. I am getting a set of stacks with uni foam in them, and I will secure them with booties

[DYSKORD]

Yep, looks good, but I'm not sure if I like the idea of using a set screw to secure the alloy "connectors" (not stacks, so performance will be questionable) to the carbs, and there's no mention of what filter (if any) is used? Another option though, which is always a good thing. Cheers, Terry. 

Hey Terry,
Its hard to tell from the pictures, so I asked, and Steeldragon has told me those are vstacks that connect the air box. Would you say otherwise? What changes would you make to the design? I personally think the slotted intake plate seems less than optimal (more turbulence). Through correspondance with TwoTired, he says that their stacks dont have quite the proper bell radius for proper/maximum performance. He nows his #$%*, but I wonder how noticeable that would be, anything is an improvement over these sh*t*y pods I got now. The filter element is indeed a universal Uni filter for dirtbikes. Maybe just sales tactics but Steeldragon claims their bikes "pull" great with the airbox.?.

[Terry in Australia]

G'Day Mate, you could be right, they might be stacks, but like you say, they don't look like stacks in the pics, and they look awfully short? If they are proper length stacks, they must extend almost to the back of the airbox? Are there rubber insulators between the carbs and the stacks to seal them? How does the airbox mount to the frame? It looks like it'd weigh close to that of the OEM airbox, so I'm surprised that there are no tabs to mount it to the frame? Looks like a lot of weight to be hanging off the back of the carbs, unsupported?

But I digress. Today I drilled out a set of 120 mains that were sitting in a set of sandcast carbs to 130. All I can say is, what a difference! I've gone from 150's to 140's and now with the 130's, it feels really good. It started right away, ran nice and clean with no clouds of black smoke, (yesterday I almost filled my garage up) and it idles smoothly @1000 RPM. Out on the road it's nice and responsive, with no flat spots or plug fouling.

I took it to my favorite stretch of country road, did my usual each way run to ensure that there was no cars, tractors or cows to run into, then gave it it's head. It absolutely leapt forward from a standing start, and revved cleanly to the redline in each gear up to fourth, where it was pulling just south of 120 MPH @ 8000 RPM, just before I ran out of road.

I did two runs like this before I chickened out and headed back, stopping for a beer at the little old Bluestone pub not far from where I was doing my "testing". A couple of Harley guys wandered over for a chat, they were very interested, and told me that they could hear me at "full song" and my old K1 sounded sweet.

They'd both had CB750's "back in the day" and had a few stories to tell, so one beer turned into couple more before I decided it was getting cold and I'd better get home while I was still "legal". I showed them Brian's Megaflow filter, and they were both impressed with the quality of his work. All in all, a great day! Cheers, Terry.    

[Tintop]

Sounds you had a successful day Terry.  Are you planning on trying any more changes, or do you think you are there?

[Kong]

I'm trying to translate this into 550-Speak.  I think what I'm seeing is +10 on the Main Jet.  Can you remind me what you are doing with your needle height and low speed circuit (jet and adjustment - if any)?

[Tintop]

I'm trying to translate this into 550-Speak.  I think what I'm seeing is +10 on the Main Jet.  Can you remind me what you are doing with your needle height and low speed circuit (jet and adjustment - if any)?

Hi Kong.  I'm running 77 PD 46A's with the following - slow jet changed from stock 38 to 40 with lowest hole in emulsion tube drilled one size larger.  This was done because the PD's are lean from the factory, and the enlarged hole should promote a slight richness at the transition.  Currently the main is a 98 (up from stock 90).  I also drilled the main emulsion tube (top hole) to again promote richness in the transition.  I have also lifted the needles one notch too again promote richness across the entire range.  Currently it starts on the choke nicely, and will idle at under 1000rpm when warm off choke (see video in my thread).  Right now I have a mid range lean condition because of the lack of baffels, which will continue to WOT.  The main jet size increases for these PD's are in small steps - 100/102/105/108/....  Gut feel right now is that my filter/pipe (with baffels) combination will require 108 / 110 mains.  I'm also going to be taking a serious look at the timing, and when / how the advance comes in.  However most of this will need further fine tuning when I install the Webcam 126-00, and slotted cam sprocket from MikeR.

[Terry in Australia]

Sounds you had a successful day Terry.  Are you planning on trying any more changes, or do you think you are there?

G'Day Brian, yeah, I reckon I'm pretty much in an acceptable "ball park" now, I could further fine tune it with needle adjustments and maybe going down one size in the main jets, so I'll keep playing with it over the next few weeks, but then I'm gonna tear the engine down and rebuild it as a stocker, and use  the head and cam in my 1060cc engine, so I'll be able to test the "Shotgun Stacks" on a fresh stock 750 engine, with both K and F2 carbs installed. Cheers, Terry.

[Kong]

Thanks for that information.  It is right around where I had guess (hoped) things would end up when I put my carbs together back in November or so.  I put in 40/105 jets and lifted the needle 1 notch, then set them aside.  I also picked up a 650 cam for it, just to spice things up a little bit.  I haven't touched my emulsion tubes - but I've got a spare set and tends to make a man brave.

It will be good a month from now when a dozen lunatics have one of these intake systems, and each of them (us) with different ideas about tuning.  The results, which will obviously be discussed at length here, should prove interesting.  Can't wait!

[Tintop]

Thanks for that information.  It is right around where I had guess (hoped) things would end up when I put my carbs together back in November or so.  I put in 40/105 jets and lifted the needle 1 notch, then set them aside.  I also picked up a 650 cam for it, just to spice things up a little bit.  I haven't touched my emulsion tubes - but I've got a spare set and tends to make a man brave.

It will be good a month from now when a dozen lunatics have one of these intake systems, and each of them (us) with different ideas about tuning.  The results, which will obviously be discussed at length here, should prove interesting.  Can't wait!

The emulsion tube thing is something I'm trying based on working with Webers.  Until I have a chance to really give it a test, the jury is still out on that.  However, when the sync was done, the comment was how clean it pulled from idle, without any flat spot.   I went to 40's from the stock 38's, as this is what is in the earlier carbs, and the PD's are lean to start.  #40 should work for most 550 situations it looks like, the possible exception being a large displacement increase.  105's are probably in the ball park, depending on how much back pressure your exhaust makes.

[Tintop]

As I mentioned I will start rejetting after the bike comes back from the next show.  To that end I send an inquiry to Sirius regarding jets for my PD's (screw in mains).  Got this reply, good deal as the price is less than 1/2 buying individual jets.

"You might want to consider the jet kit to give you some flexibility:http://www.siriusconinc.com/pro-detail.php?pid=&product_id=179] [url]http://www.siriusconinc.com/pro-detail.php?pid=&product_id=179[/url] (we can sub in whatever sizes you want)."

Kit shown includes 4 sets of jets (16 total) 105/110/115/120.

[Grnrngr]

so I'll be able to test the "Shotgun Stacks" on a fresh stock 750 engine, with both K and F2 carbs installed. Cheers, Terry.

K's in the middle and f2s on the outside or the other way round? I didn't even know you could run them together.... 

[Retro Rocket]

G'Day Mate, you could be right, they might be stacks, but like you say, they don't look like stacks in the pics, and they look awfully short? If they are proper length stacks, they must extend almost to the back of the airbox?

And be the correct shape, there's a little bit more science involved than just making stacks any shape.....

[Tintop]

so I'll be able to test the "Shotgun Stacks" on a fresh stock 750 engine, with both K and F2 carbs installed. Cheers, Terry.

K's in the middle and f2s on the outside or the other way round? I didn't even know you could run them together.... 

One rack of early carbs (K), one rack of later PD's(F).  I am sending Terry stacks for the 750 PD's as well.

G'Day Mate, you could be right, they might be stacks, but like you say, they don't look like stacks in the pics, and they look awfully short? If they are proper length stacks, they must extend almost to the back of the airbox?

And be the correct shape, there's a little bit more science involved than just making stacks any shape.....

Looking at the pictures it looks like there is no bell on the end of the stack, and it is much shorter than stock (50mm).  To mount the stacks the way he did means there can be no bell.  Otherwise you have to make the hole big enough for the mount to be fitted going from the inside.  That leaves a hole bigger than the stack diameter, and a sealing problem.  It's why I went with molded stacks, eliminates all those issues.

[DannyBhoy]

How about calling it the 'Quad Pod'..   OK yes i have been into the beer's.  Sure looks great and with correct jetting we can only hope for realistic performance gains.

[Terry in Australia]

so I'll be able to test the "Shotgun Stacks" on a fresh stock 750 engine, with both K and F2 carbs installed. Cheers, Terry.

K's in the middle and f2s on the outside or the other way round? I didn't even know you could run them together.... 

Ha ha, well there you go mate, you've learned something today!

[brandEn]

Any chance on getting an update?

Sorry to keep asking its just this is the last piece to the puzzle I am building.

[shinneh]

Any chance on getting an update?

I seconded this. Not trying to be a bother. Again, I don't want any rushing. But it's friggin exciting to read updates on what ya'll are doing with this setup. I've kinda lost enthusiasm with my 550 but reading about Terry's trial rounds have spurred me. Now if I could just stop tinkering with the dumb ol' harley.

[bwaller]

Why wait guys, just go ahead & buy one. If for whatever reason you're not using the stock airbox this will be the best other option.

[Tintop]

OK so here's the update.  Plates are ready, the stacks for the 550, & early 750's are done, and the 750 PD stacks should be ready to ship in the next couple of days.  So it looks like about a week / 10 days, and I will be able to start shipping.

Edited (italics) & updated 19/4/11

Regarding shippping - lower 48 & Canada > 6 /10 days @ $15,  4 days @ $25.  International looks to be about $35.

These are the orders for which I have deposits.  If I have missed you, PM me.  I will need a ship to address, along with the balance (including shipping) shortly.

550 - ffj / kong / SF / cafe elite / tt
750 (early) - brah pitt / odiewan (red) / y2kcowboy / cobrajunkie / tt (yellow)
750 PD's - brandEn / Terry / Voxonda / wannabridin (red)

[Grnrngr]

I'm still interested, but I think I want one for PDs now instead.   oh yeah, also a recent shift of monetary availability has left me currently dry on the beach. Tide should be coming in soon tho... meantime, please move me to the bottom of the list..

[Tintop]

I'm still interested, but I think I want one for PDs now instead.   oh yeah, also a recent shift of monetary availability has left me currently dry on the beach. Tide should be coming in soon tho... meantime, please move me to the bottom of the list..

no problem, I'll move you to the wait list, and contact those on the current list.

[Kong]

Would you like payment today for the remaining balance plus shipping?  If so let me know and I'll go to Pay Pal and do it.

[brandEn]

TT, sent the rest of my payment just now plus the extra for the 4 day shipping.