xj650 help with pods exhaust jetting from experienced poddrs

so im looking at the past posts and i understand that there are the stock airbox guys and thats fine. my last bike was a 1200 bandit that i learned the hard way on with the pods, exhaust, and jets but the xj is different and i dont know how the adjustments are done etc. to calm the stock guys i have an extra set of carbs so i can always go back =) to those of you that have successfully podded ur xj650 (mine's an 82) i wanna know what size jets you swapped in, is there an air fuel screw on these carbs that had to be adjusted along with the jet swap? did you leave the stock needles alone? i want to run open pipes or possibly dual straight thru mufflers like you would see on a suzuki tl 1000 so i want to end up with low restriction exhaust with pods or i am also curious about changing the exhaust and running the stock airbox if anyone has anything on that thought.... also my bike came with a box of misc crap that included the k&n pods so if there is a diff between brands, ill be using k&n thx in advance for any useful info for my 650 project!

 

Pods change things a whole bunch. There are a couple of kits to improve performance, I forget what they are called. Their number one or number 3 kit has been used by podders successfully. Unfortunately, it is a lot of trial and error (mostly error) trying to get the right settings.

Is there some real reason you *need* to switch to pods? These bikes are already tweaked to high performance at the outset and there is a very delicate balance to be maintained with regard to airflow into the system and back pressure going out ... Pods really mess that up.

 

Do a general search on "pods". Chacal has some good recommendations for how to find a starting point based on your stock jets. You are now pumping a whole lot more air so it will lean out. Good luck, it's still something I'd like to tinker with "some day" but for now I'm sticking with the stock setup till I get my resto finished.

 

Re: xj650 help with pods exhaust jetting from experienced po

well after a lot of trial and error i got my bandit right and she screamed... i dont so much need the pods but the exhaust is of course super quiet and since i plan on making this bike look mean with some body mods id like to have it sound mean... as for the pods i just loved the way they looked on my bandit because they open up so much space. if you google "norton commando 961" u can see pics of the look i will be going for (lots of open frame space). i got lucky and was sent in the right direction for jets and needles and whatnot, was just hoping to hear what size jets and what adjustments were made on another 650 with success

 

Re: xj650 help with pods exhaust jetting from experienced po

Good luck finding usable answers. I've found nothing concrete. The more info you dig up, the more ambiguous things get. About the time you finally give in and say "ok, I'll just stick with the stock intake boots and no airbox" or "Ok I totally give in, I'll just stay with that ugly lump of crap that the used airbox is" you get replies like "well, don't rule anything out, pods CAN be made to work a little if you bla bla bla ...."

So about the time you figure that pods are more trouble than they're worth, you get hit with a bunch of opposition. Then when you give in to the opposition you get this odd backfire of "well don't rule them out, they CAN be made to work" ... you walk away from the experience with this huge question mark floating above your head that doesn't go away for about a week or two.

I've found there are two schools of thought on using pods on this engine. 1.) "don't use them, and here's two thousand technical reasons why CV carbs hate pods". From what I can tell here, it's basically a vacuum issue. CV carbs need specific amounts of vacuum to operate properly, PODS seem to tend to reduce that vacuum. Vacuum is essentially your "throttle cable" in a cv carb. The less available vacuum the sloppier the response of the slide. Vacuum .. not throttle position ... is what directly lifts the slides in CV carbs. I hope I'm not insulting your intelligence here ... not my intention at all.

2.) Go ahead and use them. Rejet, and if you've something like Supertrapps try to tune your exhaust to help make the works happy. For some folks pods can be made to run "well enough" with CV carbs. If you're after clean looks (which I totally understand) and you're willing to put up with some goofing about to get the engine to run *well enough* ... go for it. From what I understand some folks hve little trouble, others have the mountains fall down around them. Depends on the owner, it seems.

But as for getting anything close to *absolutes* on this topic I think you'll find them few and far between.

It almost seems like the old bumblebee thing. Science says the bumblebee cannot fly. It does not abide by normal aerodynamic properties. So for all practical purposes the Bee cannot fly. Every theory out there says so. But ... just don't tell the bee that! Seems as long as nobody tells him he cannot fly, he's doing just great with it!

 

Here is the jet kit information:

http://www.dynojet.com/jetkits/index.aspx#

 

The Bumblebee's that fly are running stock ...
Not Pods.

Bumblebee's running Pods have all kind of aerodynamic issues.

Probably not a "Vacuum Issue".

More like a AIR-related issue.
Too much Intake
Not enough Main.

 

Well then, so what's up with the YouTube vids some members have dug up that show some of these bikes running *ok* with pods on them or even no airbox/filters at all?

Bottom line ... can they be made to run ok or not? If it's mains, then is there a fix? If there is no fix, then why are they so often seen?

The installation instructions for K&Ns oval pods are pretty clear. Are these just "eyewash" bs instructions then? Or is it assumed that you are running some sort of modded engine? I talked with Joji at K&N yesterday regarding the ovals. I asked him about how hard it was to get CV carbs to play nice with oval pods. He went on and on about how CVs are just so easy to deal with. Is he full of it or what?

Totally confused.

 

There ARE guys who manage to find a degree of tuning that they are satisfied with.

There are guys who are still engaged in experimentation; determined to find the right mix of needles and jets to get their bike smoothed-out to where they'll be happy with what they got.

There are 10 or 15 of our Members who say they have it right. ( 0.16% )
Not good odds.

 

Much more interesting to me is the guy who built a Fuel Injection system for his XJ.

 

Fuel Injection!
That's the way to do it.

If Yamaha made a Fuel Injected 750 Maxim 6-Speed, ... I'd camp outside the Dealership waiting for the chance to order a new one.

 

It depends entirely on your definition of "OK."

Will they increase horsepower or torque? Alone, NO. Probably the opposite.

Will they make the bike easier to ride? NO. Possibly the opposite.

Will they make it any faster? NO. Probably the opposite.

Do they look cool? That's a matter of opinion.

And you will lose the "seamlessness" of the original performance curve; the bike's ability to pull from 3000 rpm to 10,000 rpm without a hitch, stumble or sputter anywhere in the band.

So: Define "OK" as it pertains to what you want the bike to be. (Just don't get in a heads-up stoplight drag with a pure stocker.)