1979 XS400SE Running problem

Greetings from Poland.

Below I'm posting photo of my XS400 caferacer.
https://img01-olxpl.akamaized.net/i...racker-bratstyle-cafe-racer-lublin_rev007.jpg

I've got problem with idle in my motorycyle. I changed air filters and exhaust as on the photo. Now my bike after short drive or just single rev up to higher rpm stay and keeps about 4k rpm.(while just after start up works good).

I changed membranes in carburetors and leak tested the connections between carbs and cylinder head.

Now i'm thinking about changing main jets in carbs.

Have any one idea what i should check/change to make it work properly?

If you changed the the exhaust and air filters, the carburetors will need to be rejetted. You will likely need to change both the pilot jet and main jets.
There are several threads from over the years that cover this topic. I would love to be more help but I have the DOHC version which is quite different,

Search "re-jet", "jetting", "pod filter", "rejetting", etc. there are some many threads and the right one depends on your model.

Here is one from the Tech Page
http://www.xs400.com/threads/jetting-guide.4582/

Thanks anyway for answer. I have already read this topic but every hint is connected with power development and i have problem with idle.

But i will try change this jet's anyway and then i'll see what happen

Ditch those type pods and either put some uni's foam filters on it and or put the stock H-pipe back on. These type carbs hate air turbulence and those are the worst. What size pilot jets do you have and how many turns out are your pilot mix screws? Have you synced the carbs with a manometer yet?