Jets for an XJ with individual filters and stock exhaust

[Mike Hart]

I'm pretty sure I finally have my XJ dialed in. Some of you will recall a seemingly endless thread on this and other topics last fall.

I'm running EMGO individual filters with stock exhaust, and have found that 132.5 mains with 50 pilots give great pull and power with gas mileage equal to the stock setup (38mpg avg). (Stock sizes are 112.5 mains and 47.5 pilots.)

Start with a float height of 21mm (see this post in the old thread for more XJ-specific info on that). 20mm is maximum richness that still ensures float valves close, btw.

Throttle response is great everywhere, no hesitations/bogs/surges, plugs look great.

Don't know why the XJ needs such a larger increase in mains compared to the Special and Standard - the YICS system might have something to do with it.

Anyhow, any XJ folks wanting to go to individual filters for whatever reason (ease of r/r carbs, cool carb intake noise, etc) can start with the 132.5 mains. You might be able to get by with the stock pilots.

Whew - at last.

[cbird]

Uh-oh, now you have to ride it, Mike!

[Mike Hart]

Dang! Guess you're right! Will be passing thru your area on the 26th - can you come with?

Here's the link to the details

I'm headed to California. But tomorrow I'm headed to Vancouver Island!!!!!!

[Mike Hart]

WRONG! but finallly right

okay, okay, I was wrong. It took a good long trip to get it all sorted out, but I think I'm finally there.

The bike ran great with anything from 122.5 to 140 mains, though mileage suffered considerably. Doubt if I'll dyno it now, that would tell the true tale, but it was fun doing it by trial and error too.

On my 2300 mile California trip just completed, I did 2 changes while there, and am satisfied with the combo of power and mileage I'm now getting.

If stuck having to do 55 mph for a whole tank, I got 40mpg, just like I used to when stock. On heavy-handed 80+mph runs, 32mpg. I figure that's about right for a fairing and lots of baggage.

The changes: Am now running 125 mains and stock 47.5 pilots. Most of the run was near or at sea level. 2200 ft was about max elevation. Those at real elevation would probably want something in the range of 117.5 - 122.5. YMMV.