rejetting for Pods?

:?: Hello all I have a 1981 xj550 Seca RH and was just wondering about rejetting my carbs after I install pods what size jet to go to and do I really need to change them? I live in Sacramento, California just above sea level if that helps.

 

Funny, I was just talking to a bike mechanic I know about this very problem since I'm putting pod filters on my 83 XJ900.
He told me that with just one mod (either pod filters or 4-into-1 exhaust) increase main jet size by approx. 5%.

If you install pod filters AND aftermarket 4-into-1 exhaust, then increase main jet size approx. 10%.

So I've put pod filters on my XJ900 but left on the stock headers and exhaust. The stock main jets on my bike are size 102.5. Since Mikuni jets only come in half sizes, that would mean 10% = 112.5. So I went with a 5% increase to 107.5
I'm getting them early next week so I'll report on how they work out.
thx,
baz

 

ive seen lots of people only go up two sizes for pods and two for a different exhaust. There has also been people that did not rejet for pods and an open exhaust. and the bike runs real good.. Fine tuning really helps.

 

Yes, you are going to need to rejet for pods.

Stock mains are 112.5. I'd go to 117.5 or 120 mains.

Stock pilots are 35. I'd try 37.5 or 40 pilots depending on which exhaust I was using. 37.5's with stock exhaust and 40's for aftermarket.

The needle will also most likely need to be shimmed to raise it. I'd start with one additional washer under the needle.

Rejetting for pods is a lot of trial and error and headaches, but it can be done. The best way to determine if your setup is correct is on a dyno with an AFR sniffer.

Let us know how it comes out.