Topic: Pods Thread

[BAchvytrk]

I plan to run K&N pods this time around. I went with UNI's last time and after having to deal with making sure I had (1) enough filter oil as the last time I oiled them, (2) evenly applied the oil, and (3) a way to get that crap off my hands I'd had enough. I'll stick with pods but no more oil.

Last I checked, you have to oil k&n filters too. Yes they have spray on oil, but you can get spray oil for foam filters as well.

[Lostboy Steve]

Yeah but the K&N oil isnt thick and sticky like glue. I love K&N filters and to be honest I think they breathe better, but I got my UNI's so cheap, I'll stick with them for now.

[TwoTired]

With a foam filter, increasing oil volume retention does not improve filtering capability.  Only the very thinnest coating in the tiny foam "tunnels" is required.  After oil application and a bit of massaging, you cannot squeeze out or blot out enough of the filter oil to reduce it efficacy.  But, you CAN leave too much oil in it, and affect it's flow or pressure drop across the filter membrane.

Cheers,

[lucky]

I bought a set of Emgo air pods from dennis kirk, after being assured by the email clerk that they would fit the CB500 frame. Nope they don't. Oh well. No big deal, I have them sold now anyway.

A friend told me that there is another affordable type that are flatter in appearance. (he calls them pancaks filters). He told me that they sold for around $20 for the set. I have had no luck finding anything about these.

I looked at the UNI brand. At cyclepages.com they offer sets specifically marketed to the cb500 but they run just under $50 for a set of 4.

Anyone here have the UNIs? Comments?

Thanks!

I like pods too,but they will not work on the 1977-1978  Cb750.
CB550 maybe.
I tried extensive jetting  testing to get them to work.
I have 40 years experience on Japanese motorcycles.

The accelerator pump and nozzles MUST be working. All of them.

Needles must be the adjustable type with 5 notches.

I would start with a #42 idle jet. Needle CLIP lowered one notch. One step larger on the main jet if your have 4 into 1 exhaust. That may get you in the ball park.
Mixture screw about 1/2 turn less.

See the problem is that the stock air filter box was like a giant choke. So when you remove that giant choke from the intake system, most of the entire carb range is too lean.

I do not know about the CB550 stock air box, but on that same year CB750(1978) the intake area of the air box was only 3.7 square inches!!! The intake of the four carbs was 10.67 sq. inches.

See what I mean??



 

[Freaky1]

Thank god for the internet! I've seen videos on youtube showing proper oiling for K&N filters and while I have never had them in my hand the oil looks much better. I was using spray oil and it was almost impossible to get off my hands or anything else it touched. I just never felt good about the way it came out, I fully admit that a good part of that was my fault though. 

[Kev Nemo]

 I like pods too,but they will not work on the 1977-1978  Cb750. [/quote]

Seem to work fine on mine. I had to bump the mains up though.

[Caso]

Seem to work fine on mine. I had to bump the mains up though.

What is your set up if you don't mind me asking? Jet size and all that good stuff.

[Retro Rocket]

Seem to work fine on mine. I had to bump the mains up though.

What is your set up if you don't mind me asking? Jet size and all that good stuff.

And whats your definition of "working fine", the airbox works great, fine isn't good enough for me....

[Terry in Australia]

I installed 130 mains in Cliff's (Maduncles) F2 carbs and it started easy and ran fine with the "Antipod" filter Mick, I didn't have any pods to suit so they didn't get a run, but I reckon you could jet them to suit pods without too much difficulty. Yep, the stock airbox works great, no argument there, but it looks a bit daggy. Cheers, Terry.

[Retro Rocket]

I've been sitting here all night working out how to make an aluminium airbox with more volume, you will never convince me that these bikes, especially with stock carbs, will run better with pods, Brian's antipod is a different beastie that has a lot more thought  put into it, but without those stacks it would be just another pod ...

[lucky]

If ANYONE has a solution to pods on a 77-78 CB750 that truly works, and the throttle does not have to be "babied" please post all of the information.

ALL OF IT please!!  Would love to know, as would many others.

I can tell you this. The 1976 CB750 carb needles will work, but they cost $100
They are adjustable. Bike Bandit only has TWO  1977 adjustable needles in stock and they do not know if they get any more.

The 77-78 needle is slightly shorter as if they had cut off the top part of the needle.
BTW no one anywhere knows this but the space between the gooves on the needle is
only .0014 thousandths. So one person on this forum got close by using ONE shim (stainless washer ) that was .031 thousandths.


I put in two shims adding up to about .044 thousandths that sat on top of that pocket in the bottom of the slide which actually raised the needle about .056 thousandths and it ran very well in all respects in the shop.
The plugs were very black though. I think a .031 thousanths shim nder the needle =to about two notches on a adjustable type needle may work.
The pocket is .012 thousandths deep. The circlip is .010 thick.

So here is a set up that will get you very close.

1978 CB750 with pods or stacks.
4 into 1,  or 4 into 2 into 1 type exhaust.
idle jet #42
Main jet #120
needle with .031 thousandths shim sitting down in the pocket in the bottom of the slide.
Mixture screw about 1 turn open.

Needs a road test*** IF it runs well in the shop, and has good throttle response.

[TwoTired]

Throttle response issues with accelerator pump carbs, (stumble on throttle advance) is a weak, unbalanced, or maladjusted accelerator pump.
  You can run the pilot circuit as lean as you want (EPA demanded this for 1978).  The accel pump is what makes the throttle twist work.

Length isn't the only difference between various model slide needles.  Often the taper angle is different too, and maybe even the base diameter.

You can't tell much by looking at them, they must be measured.  They work in concert with the needle jet.

[lucky]

I have carefully measured the 1976 needles and compared it side by side with the 1978 needle. They are a match. I measured in several places on both needles and compared them. The taper is the same.

[lucky]

I am pretty happy with the uni pod filters I got from dennis kirk.

http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=30814&store=Main&catId=413&productId=p30815&leafCatId=41302&mmyId=9297

Doug

Not sure what this means.

[TwoTired]

I have carefully measured the 1976 needles and compared it side by side with the 1978 needle. They are a match. I measured in several places on both needles and compared them. The taper is the same.

But, you said the length was different.   So, you need a map showing the taper diameter vs distance from the needle clip, in order to compare needle parameters.

[Terry in Australia]

I've been sitting here all night working out how to make an aluminium airbox with more volume, you will never convince me that these bikes, especially with stock carbs, will run better with pods, Brian's antipod is a different beastie that has a lot more thought  put into it, but without those stacks it would be just another pod ...

Nope, I didn't say "run better" mate, as I don't have a dyno in my garage and I didn't have another F2 to compare it to with the stock airbox fitted, and Cliff's engine was kinda tired anyway, but for normal "start it up and ride it all day" use, it was fine.

I can tell you from experience though, that I removed the antipod from my K1 and installed my old K&N pods just to see what the differences would be, rode it from my place to Kinglake and back, (from 300 feet above sea level to 2000 feet above sea level) a ride I've done many times with the antipod in place, and I didn't notice any real difference.

I think the aluminium airbox is a good idea though, I don't like pods all that much, and even less in wet weather like we have here at the moment, I've heard that water injection is a good thing, but I'm not keen on exposing my filters to the rain, particularly when the bike is parked outside the pub. Cheers, Terry.  

[Boulevard_beck]

What about using pods, but installing a big see-through plastic enclosure around them with a tiny inlet? You get to see the cool looking pods, but you get the air flow of the stock box! Hmm...borderline stupid or amazing??

[lucky]

I have carefully measured the 1976 needles and compared it side by side with the 1978 needle. They are a match. I measured in several places on both needles and compared them. The taper is the same.

But, you said the length was different.   So, you need a map showing the taper diameter vs distance from the needle clip, in order to compare needle parameters.

Let me clarify.  If you take the two needles and put them side by side standing on the point the measurements are identical.  It is just that the 1978 needle has the top cut off for some reason ,about the length that would be above the top groove.

So from the pointed part upwards they are the same all the way up. Same taper I checked extensively. I Had to mark and measure them many times to get it right.
I used a dial calipers 0-.100 in one revolution.

[Terry in Australia]

What about using pods, but installing a big see-through plastic enclosure around them with a tiny inlet? You get to see the cool looking pods, but you get the air flow of the stock box! Hmm...borderline stupid or amazing??

The former, not the latter. Ha ha, the benefit of the stock airbox, apart from acting as a "still air" box, is that it has inbuilt velocity stacks, which work well with stock CB750 carbs. Now a clear "still air box" around Brian's "Antipod" setup might be amazing?

[Retro Rocket]

I've been sitting here all night working out how to make an aluminium airbox with more volume, you will never convince me that these bikes, especially with stock carbs, will run better with pods, Brian's antipod is a different beastie that has a lot more thought  put into it, but without those stacks it would be just another pod ...

Nope, I didn't say "run better" mate, as I don't have a dyno in my garage and I didn't have another F2 to compare it to with the stock airbox fitted, and Cliff's engine was kinda tired anyway, but for normal "start it up and ride it all day" use, it was fine.

I can tell you from experience though, that I removed the antipod from my K1 and installed my old K&N pods just to see what the differences would be, rode it from my place to Kinglake and back, (from 300 feet above sea level to 2000 feet above sea level) a ride I've done many times with the antipod in place, and I didn't notice any real difference.

I think the aluminium airbox is a good idea though, I don't like pods all that much, and even less in wet weather like we have here at the moment, I've heard that water injection is a good thing, but I'm not keen on exposing my filters to the rain, particularly when the bike is parked outside the pub. Cheers, Terry.

I have also been looking into some "ram tubes" or something similar with maybe a butterfly at the mouth of each so at speeds over 70-80KPH, 40-50 MPH {for our American brothers} i can manually open the tubes {with an old choke cable} to let more air into the box at higher speeds, there are a lot of Japanese sports bikes with set ups similar to this and i know i have no scientific method to know exactly when opening the airflow up would be optimum but i have wanted to try this for a while now. I think if there is any benefit it will be fairly easy to tell as the butterfly's can be left closed for a run and time and speed measured against the same run with the butterfly's open....If i didn't have this affliction to modify everything i own, would have a garage full of running bikes.....But i digress...  

[Really?]

All this poddy talk makes me wanna go...

[Terry in Australia]

I have also been looking into some "ram tubes" or something similar with maybe a butterfly at the mouth of each so at speeds over 70-80KPH, 40-50 MPH {for our American brothers} i can manually open the tubes {with an old choke cable} to let more air into the box at higher speeds, there are a lot of Japanese sports bikes with set ups similar to this and i know i have no scientific method to know exactly when opening the airflow up would be optimum but i have wanted to try this for a while now. I think if there is any benefit it will be fairly easy to tell as the butterfly's can be left closed for a run and time and speed measured against the same run with the butterfly's open....If i didn't have this affliction to modify everything i own, would have a garage full of running bikes.....But i digress...  

I don't know what, if any, benefit there'd be in ram tubes with butterfly's Mick, but a simple hinged flap on the airbox itself that you can regulate with an old choke lever might work, and you could test the merits with an exhaust gas analyser. The more I think about a cool aluminium airbox, the more I want to make one!

[TwoTired]

What about using pods, but installing a big see-through plastic enclosure around them with a tiny inlet? You get to see the cool looking pods, but you get the air flow of the stock box! Hmm...borderline stupid or amazing??

Why not just use 1/2 a v-stack?

[Retro Rocket]

I have also been looking into some "ram tubes" or something similar with maybe a butterfly at the mouth of each so at speeds over 70-80KPH, 40-50 MPH {for our American brothers} i can manually open the tubes {with an old choke cable} to let more air into the box at higher speeds, there are a lot of Japanese sports bikes with set ups similar to this and i know i have no scientific method to know exactly when opening the airflow up would be optimum but i have wanted to try this for a while now. I think if there is any benefit it will be fairly easy to tell as the butterfly's can be left closed for a run and time and speed measured against the same run with the butterfly's open....If i didn't have this affliction to modify everything i own, would have a garage full of running bikes.....But i digress...  

I don't know what, if any, benefit there'd be in ram tubes with butterfly's Mick, but a simple hinged flap on the airbox itself that you can regulate with an old choke lever might work, and you could test the merits with an exhaust gas analyser. The more I think about a cool aluminium airbox, the more I want to make one!

I plan on cutting up a couple of wrecked boxes i have to make a bigger volume one and to see if i can fit it in there, feel free to test the idea, At the speed i am moving with my bikes you will probably be marketing yours and making a living out of them by the time i make mine....

[Terry in Australia]

Ha ha, the box itself will be a piece of cake to mock up from cardboard and trial fit on my bike, the only thing holding me back is the AC/DC TIG welder I bought for my 50th birthday two years ago Mick, it didn't come with an instruction manual and there are around 3 million buttons on the thing that obviously do something important, so I just sit and stare at it, hoping that eventually I'll guess how to set it up so I can actually weld some aluminum! Cheers, Terry.