Author Topic: Need help with POD filters install Bike shuts off at high rev's (Read 10626 times)

Retro Rocket · « **Reply #25 on:** April 18, 2013, 04:01:45 PM »

Quote from: jamesbekman on April 18, 2013, 06:43:29 AM

Its just trial and error when jetting a carb for more airflow. These bikes are not so unique to the world. Tons of race bikes, race cars run no filters at all. If you feel like messing with the jetting then go have a blast!

Nice guess but not even close, Its not just about "more airflow" its about a smooth supply of uninterrupted controlled airflow, directed by the velocity stacks, to be even and not turbulent, you don't get that with pods unless they have inbuilt stacks , the whole Honda induction system was designed as a whole, the airbox, velocity stacks and carbs were engineered to work with each other, thats why its far easier to tune these old SOHC's with the airbox and all its associated parts. Its very well documented on this forum. The Keihins are a far more fussy carb than the Mikuni's used on other large bikes of the era, look at the Suzuki GS and Yamaha XS1100 airbox for instance, they have straight tubes, no velocity stacks , thats because their carbs are designed different to the Keihins. There are plenty of bikes that run well with pods, the SOHC/4's aren't one of them, unless you are running different carbs, that brings up a whole new kettle of fish....There are pods and then there are PODS....

All modern race bikes run stacks and airboxes, i wonder why....

dave500 · « **Reply #26 on:** April 19, 2013, 12:54:36 AM »

you jet for mixture not airflow,,you use pods for looks only on these and put up with however/whatever if you even do actually know what your doing,,so after stripping the threads on the float bowl screws after so many removals and a dozen plug "chops"oh forget it,,theres so many other threads on pods,i vowed to never post in another one,,so now i have to take my pennance,,i have to now drink a beer through a pod filter,id rather drink one through a proper airbox!

Stev-o · « **Reply #27 on:** April 19, 2013, 04:11:13 AM »

Dave - no popcorn with that beer?

Smoke Detector · « **Reply #28 on:** April 19, 2013, 05:50:53 AM »

Between pods and oil, not to mention the whole 180 degrees thing, there's actually getting to be quite a few popcorn threads on here.

dave500 · « **Reply #29 on:** April 19, 2013, 06:15:10 AM »

man?i iknow not to be rude and all that #$%*,and i dont wanna upset any god fearing members and all,,but jesus christ!!a man can only bear/beer so much,,so i feel so much better now!phew,,whose responsible for those 72 virgins?you still have a couple left over,oh hang on,,one wants to talk cam angles and some #$%*,,allah bear with me!

jamesbekman · « **Reply #30 on:** April 19, 2013, 08:07:37 AM »

Mixture = fuel to AIR ratio at ANY given instance. Ive never seen a forum so scared to tune a carb.

I fully understand that its a lot easier to just put the correct stock jets etc in and run the air box and just go.

One drawback to that and its something we should all be looking into is its really rare to get stock pipes. All I see are 4 into 1 pipes nowadays.

I also see a million posts of just put the stock filters on and not a whole lot of hey I have pods this is what works for me, these are the drawbacks, these are the gains...

crazypj · « **Reply #31 on:** April 19, 2013, 08:15:32 AM »

Stock jetting is way too lean with pods, particularly cheap ones.
It isn't easy to get jetted right, when you fit bigger main jets you get problems at other throttle positions
Really needs different throttle slides and needles to work properly.
If your experienced rider you can work around the shortcomings and keep motor at rpm 's where you don't have issues

dave500 · « **Reply #32 on:** April 20, 2013, 02:30:40 AM »

4-1 pipes on these dont really need any jetting changes anyway,,its some sort of myth that needs to be busted but i couldnt be #$%*ed,,as crazy says if you can feel your engine youll know whats going on and ride accordingly to compensate for how the engine runs if youve gone the pods route,,you must have been lurking a long time with only 20 posts to decide this forum has so many members afraid to tune carbs,,why not share some secrets or tips with us?

jamesbekman · « **Reply #33 on:** April 20, 2013, 06:28:14 AM »

Hey Dave!

No ill will here on my part. I'm just from NY. I just got back into bikes... I've been in the British sports car world for quite a while because they can be cheap an fun as well. I've just messed with webers and SU carbs. The SU's basically operate by the same design albeit a little simpler It's all about the needles with those. They also have a ton of options or needles and custom made needles as well. People who really get into it even sand down certain parts of their needle to make a richer needle at different engine loads. I'm in no way saying I know everything, far from it But with an o2 sensor mounted you could see what's going on a little better instead of having to pull plugs and do runs or chops as everyone calls it. Is there any source for needles other than stock? I just know of apple hydraulics in regards to needles for SU carbs. Thanks for the info on the 4-1 pipes.

James

Retro Rocket · « **Reply #34 on:** April 20, 2013, 03:08:54 PM »

Quote from: jamesbekman on April 19, 2013, 08:07:37 AM

Mixture = fuel to AIR ratio at ANY given instance. Ive never seen a forum so scared to tune a carb.

I fully understand that its a lot easier to just put the correct stock jets etc in and run the air box and just go.

And this is what you don't understand...

Quote

, the whole Honda induction system was designed as a whole, the airbox, velocity stacks and carbs were engineered to work with each other, {i'm not saying this is great, its just the way it is} thats why its far easier to tune these old SOHC's with the airbox and all its associated parts. Its very well documented on this forum.

Its not rocket science and if you know as much about THESE bikes as you are making out you would already know what i've repeated here. Plenty of carbs work with GOOD pods, the SOHC Honda's are different, if you think that all carbs are equal then you would be sadly mistaken.... The Honda Keihins like, and run best, with no turbulence in the carb throat , you DO NOT get that with pods,

"Mixture = fuel to AIR ratio at ANY given instance" that is only part of the equation. Explain to us all why all modern race bikes run airboxes and velocity stacks, remember, we are not tuning cars here....

jamesbekman · « **Reply #35 on:** April 20, 2013, 07:09:09 PM »

Cranky pants... Drop the attitude. Maybe we can actually talk about something here.

crazypj · « **Reply #36 on:** April 20, 2013, 08:27:53 PM »

Modern SPORT bikes as well as race bikes run air boxes and velocity stack because they have ram air systems that work and fuel injection to take advantage of the cooler air taken from high pressure area at front of fairing
Earlier carburetted models also worked but started getting electronic valving on carbs to compensate for varying airflow, etc
A modern system has no comparison with the1960 'state of the art' stuff we are dealing with
The only thing I can really agree with, Kei-Hin carbs are REALLY difficult to get working properly with K&N style filters.
I know how to make CB350 and CB360 work properly, early CB750 is reasonably easy, CB550F can be done but none of the DOHC will work right without stock airbox

Retro Rocket · « **Reply #37 on:** April 20, 2013, 09:23:14 PM »

Quote from: jamesbekman on April 20, 2013, 07:09:09 PM

Cranky pants... Drop the attitude. Maybe we can actually talk about something here.

Read into it what you like, where's that attitude...? The info's all over the forum, use the search function....

PJ, the ram air systems don't work at lower speeds {where a lot of the problems lie with pods}, the very first ram air type systems were introduced in the early 1990's, these systems open at higher speeds or revs. There are still plenty of comparisons, when you are talking systems that are entirely designed to work as a whole, there is no difference except that the systems have been refined much further, better stack design, bigger volume in the airboxes and the understanding {thats been round for ever from Honda} the smooth non turbulent air works far better than disturbed turbulent air, yes, Honda were ahead of their time in designing their induction systems, they just hadn't refined it as far as it is now, like frames and suspensions, the basics have been there for years, its just better executed these days... There are guys here in Australia racing some of the fastest Honda 750's in the world and they are using custom made airboxes, i have a pic somewhere, i will post it.... The biggest problem with pods is that most guys put them on "just for looks" or because its a little difficult to get them on and off, most of these people don't have a clue how to tune these carbs at all and ride round on bikes that run like sh1t {even thinking that they run well}, there is an ever increasing amount of members that are reverting back to the original airbox and comment that "the bike has never run better", there are very good reasons for that. Have you noticed there is no baseline tuning for pods..? The same questions are asked regularily on a weekly basis on this site. I've been looking into this stuff for years, thats why i am using modified airboxes on all 3 of my builds and none of them even have stock carbs, one even has fuel injection. I guarantee all 3 will be easier to tune they way they will be set up than they would be wearing pods {and they won't sound like they are trying to suck my balls out the leg of my pants}

....... The biggest thing people forget is that race bikes only run flat out, not really needing any state of tune under 5000+ rpm for older bikes and closer to 10,000 for more modern bikes, early race carbs didn't even have idle circuits , on the road you need a system that works at all rpm's, grab a hand full of throttle and get a huge flat spot and tell me thats better than the airbox, especially when there's some idiot trying to run you over. My mid 1980's GPX750 race bike had carbs and the airbox and that thing was awesome {best street bike i ever owned}, bought it off the guy that raced it { an Aussie champion and brilliant rider and a good friend} and , believe it or not {long story} that bike was built by a HRC mechanic.... If you must use pods then try and use quality ones with inbuilt stacks, not perfect but much better....

dave500 · « **Reply #38 on:** April 21, 2013, 12:58:56 AM »

auto(car)carburettors have more fuel circuits than these old keihins,they have an idle/off idle,the main circuit,a power enrichment and also an accellerator pump delivery circuit,you can alter the air filter with no mods to the stock jetting 99.99% of the time,,these carbs have two circuits,idle then main more or less,,they dont have the smooth level by level gradually increasing transition from idle to main and power,,so sometimes the factory jetted the slow circuit richer to compensate,they still cany be suddenly wound open from idle,,using pods just upsets the delicate balance the factory built inot these engines to make them as flexible as could be say through stop start traffic,,nothing wrong with pods if you ride full on flat out a lot,,and care less for a flat spot here or there and a hanging low or high unreliable idle,,,and a #$%*ty cruise feel.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #39 on:** April 21, 2013, 11:11:58 AM »

Girls, girls, girls, you have chased off the original poster

Let's see how his carb tuning turns out. Nothing wrong with trying pods, just not easy.

jamesbekman · « **Reply #40 on:** April 22, 2013, 02:50:45 PM »

Ha yes it has. Thanks for the info Dave! Im here to learn from guys like you!

crazypj · « **Reply #41 on:** April 22, 2013, 04:14:17 PM »

Kawasaki was the first motorcycle manufacturer to use real 'ram air' (ZX750?)
It was developed for them by Leon Moss (LEDAR Race Developments)
It was called fresh air ram technology system and almost got into production as Kawasaki F.A.R.T.S

The problem with 'pods' isn't at low speed but in the transitions around 4,000 rpm
Kei-Hin CV carbs have pilot (slow) system, fixed primary main jet which also supplies fuel to pilot jet then a secondary main jet with conventional emulsion tube, needle jet, etc
Kei-Hin 2 jet mechanical slide carbs seem to be more difficult to jet than Mikuni, but it's probably because Mikuni is quite crude in comparison.
The Honda system was always designed as a complete system, from air box entry to exhaust tip outlet
To 'improve' it without airbox needs a lot of work

Retro Rocket · « **Reply #42 on:** April 22, 2013, 04:18:32 PM »

Quote from: crazypj on April 22, 2013, 04:14:17 PM

Kawasaki was the first motorcycle manufacturer to use real 'ram air' (ZX750?)
It was developed for them by Leon Moss (LEDAR Race Developments)
It was called fresh air ram technology system and almost got into production as Kawasaki F.A.R.T.S
The problem with 'pods' isn't at low speed but in the transitions around 4,000 rpm
Kei-Hin CV carbs have pilot (slow) system, fixed primary main jet which also supplies fuel to pilot jet then a secondary main jet with conventional emulsion tube, needle jet, etc
Kei-Hin 2 jet mechanical slide carbs seem to be more difficult to jet than Mikuni, but it's probably because Mikuni is quite crude in comparison.
The Honda system was always designed as a complete system, from air box entry to exhaust tip outlet
To 'improve' it without airbox needs a lot of work

I very nearly bought one of those Kawasaki's new PJ, just couldn't get my head around those 2 big tubes going through the tank, not looking at them, but when on the bike riding it, they just looked a bit weird and out of place...

crazypj · « **Reply #43 on:** April 22, 2013, 04:25:03 PM »

I was working in a Suzuki/Yamaha dealers when Kawasaki launched it
We called them Hoover, the vacuum cleaner bikes

It actually worked real well but looked real weird
Still preferred a nice Exup thou or Gixxer 1100

Retro Rocket · « **Reply #44 on:** April 22, 2013, 04:28:04 PM »

Quote from: crazypj on April 22, 2013, 04:25:03 PM

I was working in a Suzuki/Yamaha dealers when Kawasaki launched it
We called them Hoover, the vacuum cleaner bikes
It actually worked real well but looked real weird
Still preferred a nice Exup thou or Gixxer 1100

Agreed, i loved my Gixxer, 1100J last of the slabbie's , unfortunately it was stolen whilst moving house in 1990 , i'm still pissed about that...

Stev-o · « **Reply #45 on:** April 22, 2013, 06:45:18 PM »

Is this what you guys are referring to? See 2nd pic
What does it do??

http://www.kawiforums.com/sale-general/40454-fs-1989-kawasaki-zx750-sale.html

Jahaaji · « **Reply #46 on:** April 22, 2013, 06:57:04 PM »

Well I put the stock air box back on and all is good. Problem no more. I think later on I will try again with the PODs and see.

Retro Rocket · « **Reply #47 on:** April 22, 2013, 07:58:44 PM »

Quote from: Stev-o on April 22, 2013, 06:45:18 PM

Is this what you guys are referring to? See 2nd pic
What does it do??

http://www.kawiforums.com/sale-general/40454-fs-1989-kawasaki-zx750-sale.html

Basically it forces air into the airbox over a certain speed... More air, more fuel = more speed....

crazypj · « **Reply #48 on:** April 22, 2013, 08:18:13 PM »

F.A.R.T.S. yep, that's the one

It actually improves things just about everywhere as the air isn't heated by engine and breaths from high pressure area at front of bike.
I think it needs to be doing 100+ before the air 'pressure' balances engine requirements (depending if you have headwind, tailwind or still air)
Hayabusa gets around extra 14~20 hp @160mph compared to static dyno test (no idea how they measured it, unless they put dyno in a 200mph wind tunnel?)

vonvendetta · « **Reply #49 on:** April 22, 2013, 08:18:22 PM »

I know a lot of people are hating on the pods. Someone explained to me the reason they don't work well is because it needs the pressure to pull the fuel and the pods give it too much air to pressurize.... in a way. What about pods and another foam type of filter to cover them, or even like a bonnet?

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Author Topic: **Need help with POD filters install** Bike shuts off at high rev's (Read 10626 times)

Author Topic: Need help with POD filters install Bike shuts off at high rev's (Read 10626 times)