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Discussion Starter · #1 ·
I'm thinking about changing to pods on my CJ but I can tell that standard cones won't fit around the battery in its stock position. Has anyone used angled pods to fit around the battery? What brand and model would be suitable? The Uni UP-4200 AST looks like it might do the trick.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/231736883799
Any other recommendations? (Other than leaving the stock air boxes alone, which I know many recommend)
Thanks.

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Whatever you do, don?t toss or sell your factory boxes ;)

I?m not sure if the CJ guts are the same as the CB, but the PO who put pods on my bike used the angled rubber tubing from the factory airboxes to offset the pods wide of the battery box (so carbs -> angle rubber -> straight pods). Worked brilliantly for spacing, though the bike ran about as garbage as can be expected.

I think PJ recommends K&N RU1820s if you?re gonna pod, but that may assume he?s modding your carbs too.

What?s the motivation for switching to pods, if I may?
 

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I have used UNI foam filters on my bike before. The flexible nature of them allows them to curve around the battery box. I had pretty good success with them until I backfired through the carbs and lit them on fire, which got me to where I am at with my overall rebuild project.
 

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Discussion Starter · #5 · (Edited)
Whatever you do, don?t toss or sell your factory boxes ;)

I?m not sure if the CJ guts are the same as the CB, but the PO who put pods on my bike used the angled rubber tubing from the factory airboxes to offset the pods wide of the battery box (so carbs -> angle rubber -> straight pods). Worked brilliantly for spacing, though the bike ran about as garbage as can be expected.

I think PJ recommends K&N RU1820s if you?re gonna pod, but that may assume he?s modding your carbs too.

What?s the motivation for switching to pods, if I may?
No, I don't plan on getting rid of the OEM air boxes so I can back out of the mod if I want to. Using the original boots to angle the filters around the battery might work on the CB, but I think the CJ's boots have an oval opening on the filter end, so it might be hard to find a filter that fits. I confess my main reason for trying out pods is looks. I'm doing a cafe build on it and stock airboxes/side covers don't seem to be part of the "look". I'm also considering relocating/downsizing the battery which would remove the need for angled pods, but I want to keep my options open. The other reason I'm thinking about pods is the bike currently has uneven performance between the cylinders (one plug is normal, one is sooty) so I have to mess around with the fueling anyway. I don't see much difference tuning to stock or aftermarket air filters.

I have used UNI foam filters on my bike before. The flexible nature of them allows them to curve around the battery box. I had pretty good success with them until I backfired through the carbs and lit them on fire, which got me to where I am at with my overall rebuild project.
Yikes! I guess I'll stay away from those then. I thought the red foam would look cool, but I wasn't planning to add flames!
 

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I remember seeing a bit of plastic in there - I think the PO might have rounded them out by sticking a piece of PVC into it. I gave up on trying to tune pods though, a bit of open cell filter foam fixed my nasty stock boxes right up and it was running like a dream until I stripped it all down like an idiot :) gotta have hobbies, breaking things that work is just mine.

Anyway, I think I've still got my angle boots in the garage - it looks like a bomb went off, but I'll dig em up and send a couple of pics. You're welcome to em if you want to cover shipping, they fit the standard Keihin 745B that came on CB/CJ360s.
 

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Discussion Starter · #7 ·
I remember seeing a bit of plastic in there - I think the PO might have rounded them out by sticking a piece of PVC into it. I gave up on trying to tune pods though, a bit of open cell filter foam fixed my nasty stock boxes right up and it was running like a dream until I stripped it all down like an idiot :) gotta have hobbies, breaking things that work is just mine.

Anyway, I think I've still got my angle boots in the garage - it looks like a bomb went off, but I'll dig em up and send a couple of pics. You're welcome to em if you want to cover shipping, they fit the standard Keihin 745B that came on CB/CJ360s.
Thanks Spiro, I'd be interested to see a picture of your boots, but don't spend your weekend looking for them. I also have been using oiled foam inserts in the original paper filter housings and it seems to work pretty well. Mind you, I don't know the cause of the sooty plug on one side, and I suppose it might have something to do with the filter. That will be another thread for another day though.
 

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There is a reason why Honda uses an airbox on ALL of their carbureted motorcycles...
 

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Yes the reason is the air boxes being connected together helps smooth out the pulses from a twin cylinder 4 cycle motor for the air flow into the carbs.
 

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Yes the reason is the air boxes being connected together helps smooth out the pulses from a twin cylinder 4 cycle motor for the air flow into the carbs.
All CV carburetors are very sensitive to the air pressure. The slides will not go up and down together if there is any difference in airflow. I have never tried, or would I want to try to get a pair (or four) CV carburetors working with independent air filter of any kind. The airbox provides a stable air pressure along with smoothing out the flow. Without an airbox, the carbs can never be synchronized.
 

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I don't know if the clearance issues are different on the CJ, but I use individual K&N pods on my CB350 successfully. I think they look great, and the performance is excellent from idle to redline. You cannot just bolt them on and expect them to work, which is why many people will claim that they don't work. If you're willing to put a bit of effort in, these can be a great modification.

From a performance standpoint, you're going to want longer intake tube between the filter and the carb anyway, so that may resolve your fitment issues. On the 350, there's just enough of an angle that they sit right along side the battery.
 

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I don't know if the clearance issues are different on the CJ, but I use individual K&N pods on my CB350 successfully. I think they look great, and the performance is excellent from idle to redline. You cannot just bolt them on and expect them to work, which is why many people will claim that they don't work. If you're willing to put a bit of effort in, these can be a great modification.

From a performance standpoint, you're going to want longer intake tube between the filter and the carb anyway, so that may resolve your fitment issues. On the 350, there's just enough of an angle that they sit right along side the battery.
What did you do to make them work?
 

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Discussion Starter · #14 ·
I wrote it up a while back in this thread.

It's the post dated 06-07-2017 09:22 AM

http://www.hondatwins.net/forums/63...b400-cv-carbs-pods-how-make-them-work-31.html
Hey I haven't checked back on this thread for a while so I wasn't aware of all the good responses. I've decided for now to just keep the air boxes. One of the reasons I was ready to get rid of them is my side covers are kind of ugly and dinged up with their present paint. I figure a black satin respray will help them blend into the background and not detract from the cafe look too much. That said, I still wouldn't mind trying pods out sometime. The CJ's air boxes are totally separate, so I wouldn't lose the equalizing effect someone mentioned earlier.

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FWIW, I've used generic foam pods, K&N foam pods, cheap clone pods...What is the result? I spent a bit of money replacing my stock (lost) airboxes and now the bike runs as well as it can. As said by others, the stock airbox does a number of good things. It creates a large pool of still air (A plenum) for best CV slide operation; It makes sure both carbs get the same air pressure, at the same temperature, for equal cylinder performance; The inlet to the carbs is the right length for smooth, laminar flow, allowing the slides to work as designed; Each cylinder pulse draws air through BOTH filters, giving a low restriction to the air coming into the airbox.

If you are running stock CV carbs, the highest, smoothest performance is from the stock airbox. The best way to do any improvement is too replace the stock airbox filter paper element with a lower restriction foam element.

While your bike won't die or completely fail from pods, the performance of pods, in most cases, is worse than stock. In addition, the tuning of the stock CV carbs is next to impossible (only a couple of people know how to do it), and even when done right, they don't perform across all RPM ranges nor have the drivability quality of the stock airbox system.

You are totally free to choose any path you want, but in any case, your bike will never run as well as it does on the stock intake system. Do some reading in the carburetor sections, check out pods, running rich, stumbling, throttle response issues....you will find pods do not really improve running or reliability.

You can put the pods on for a cool look, but be aware that you will degrade the performance.
 

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Hate to pile on, but my bike had K&N pods when I bought it. I put a couple of thousand miles on it and thought it ran “fine”. Then I ponied up for stock boxes and was impressed with difference. Two things stood out, quieter (much less induction sound) and stronger pull from 7k to redline. No contest, stick with stock, if you want top performance.
 

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It would be interesting to see someone try to dyno tune pods on stock Keihin carbs and custom exhaust. Then compare to the stock setup.
 

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Hate to pile on, but my bike had K&N pods when I bought it. I put a couple of thousand miles on it and thought it ran “fine”. Then I ponied up for stock boxes and was impressed with difference. Two things stood out, quieter (much less induction sound) and stronger pull from 7k to redline. No contest, stick with stock, if you want top performance.
I disagree. No contest, put on pods, free-flowing exhaust and adjust carbs if you want top performance. Have had my 350 for 20 years and other CB's too. I'm 100% sure my 350 will run circles around a stock 350.

There are so many people that say it won't work, because they've done it wrong. Ever seen a race bike running stock intake, exhaust and carbs?
 

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I disagree. No contest, put on pods, free-flowing exhaust and adjust carbs if you want top performance. Have had my 350 for 20 years and other CB's too. I'm 100% sure my 350 will run circles around a stock 350.

There are so many people that say it won't work, because they've done it wrong. Ever seen a race bike running stock intake, exhaust and carbs?
Race bike don't sit at lights, stop and go traffic. An engine tuned for being strong in the upper third rpm, is not strong in the lower third. Most race bikes aren't using stock carbs, stock timing, stock compression. Race bikes are not the easiest to start. Race bikes also use race tires. They don't work well on wetbpavement. So race bike comparisons are false comparisons.

Notice I did not say it won't work, just that it is not the best choice for street riding and drivability.



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