Having trouble with dreaded “pods”

1982 XJ650 Maxim YICS

So I did it. I put pods on my bike. Airbox was destroyed and I decided I would go with pods and be patient.

Well now I’m having problems. Laugh it up, never seen a pod thread where pod guy wasn’t torn to shreds haha.

Intake boots aren’t leaking, gaskets are good.
Open headers atm (not directly off the head, just no baffles)

Mixture screws at 3 turns out, bench synced, nothing sticking, EXTENSIVELY cleaned and rebuilt carbs. I’d eat off these things.

now it’s time to start, and it jumps to 8k immediately. Every time. Idle screw all the way out. Doesn’t matter if I mess with choke. Throttle not sticking. Please advise.

sure, vacuum leak. But 8k rpm? Choke doesn’t affect it? Basically closed throttle doesn’t affect it?

had an older Honda Magna v4 few years back, giving me ptsd that thing never ran right

 

8,000 is serious rpm’s
I’d say a butterfly is not closing.
And if one butterfly is not closing it will hold all 4 open

 

Also make sure you have play in the throttle cable. There should be an adjuster near the handle bar end of the cable:



You'll be able to tighten up the slack after you get a vacuum sync done on the carbs.

Tony.

 

As mentioned about butterfly valve sticking.
Since you have pots, I would think you could pull one or all and look into the back with an mirror and flashlight to see that the butterflies are all closed.
If they ARE, then I"d guess you have fuel enrichment needles not going all the way down.
you MAY have installed the little forks that pull up the FE needles backwards?
They should move up/down with the lever and that lever should move left/right about what? 1 1/2-2"? Maybe someone can say.
But the important part is that when you have the FE all the way to the right (off) that the forks holding the pins will move down far enough that a gap is present in the top of the notch to the fork showing you that the FE is all the way seated closed.

My FE being fully on I think brings me up to like 4-5K


BTW, Pods, Has anyone ever experimented with restricting intake air flow on Pods to make them act like a stock airbox?

 

Pods are less restrictive than the stock setup. Back when I was figuring out why my bike wouldnt run, it was on pods, I cut up an old t shirt and put it between the pod and the carb. That increased the restriction through the pods, making it run like stock until I could source an airbox. As per the question of 8k rpm, back when I was fiddling with my pods, it was running so lean that it was only firing on 2 cylinders at random. When I would spray starting fluid or carb cleaner, it would jump up to around 7k rpm like this guys. Just to see what is going on, I would do what Melnic said, pull a pod off and make sure at closed throttle, everything is down as it should. What you can also do, which is what I did way back when, is pull all the pods off and grab a flat piece of wood. You can put the wood across the intakes of all the carbs, essentially closing them off. Try and start the bike and see if it runs. Technically speaking, there is a point for your setup where the board will give the perfect air fuel ratio, whether that be covering 25% or 62.342% of the intake with the board. Youll know you get it when it idles not at 8kprm.... Only other thing I could suggest is to look at the plugs to see if your surge is caused by running lean.

 

Be sure to look here:
https://www.xjbikes.com/forums/threads/good-information-on-pods-vs-airbox.113230/

Part of the problem with pods is that they lack the velocity stack type of inlet that the factory rubber boots provide.

 

Interesting. I wonder if an inner sleeve could be put in to create that velocity stack effect?

 

Your high rpm issue has nothing to do with your filters, but everything to do with incorrectly set up throttle discs - aka bench setting the butterflies. Take them off and make sure they are bench set using the first progression hole edge method. Set your mixture screws 3 turns out.
Your xj will then start and idle. Do a carb balance using vacuum gauges.
After this things get complicated, jetting alone is not guaranteed to get results, you may need different needles and or new or modified springs.

 

I think I recall seeing posts about somebody adding something to add some length between the carb and pod, helping to smooth out the air before hitting the carb. I've had some ideas rolling around my head about designing intake tubes to smooth out the air - but that's an experiment for the future.

If you look at the carb-to-airbox boots on the XJ700 models (both the airheads and waterheds) they REALLY look like velocity stacks.

True dat. I think the pods just add an extra level of uncertainty that make it harder to troubleshoot.

 

I had forgot to mention I have rejetted, however it was last summer so for the life of me I can’t remember what I jetted at. I found a forum on here where several people found a size that all worked for them so I went with that.

 

Thank you all very much, this was extremely helpful. Gonna pull tomorrow and do a second bench sync, make sure throttle cable is up to 100% good. I’m glad that running lean isn’t the cause of 8k rpm surge, it makes sense now but in the moment I assumed it was my only issue. XJforums save the day once again