jetting the 82 xj1100

[flb_78]

I did read the entire MEGATHREAD on jetting the 82 XJ1100. The last that I read said that with the stock exhaust and 4 indy pod filters, Mike was running 140 mains with 50 pilots. I just got my 82 running again. I am going to install 4 indy pod filters and 4-1 MAC exhaust. I had this installed before and had no midrange, good top end but no midrange. I'm just wondering what would be recommeded for an 82 XJ110 with 4 indy pod filters and a MAC 4-1 exhaust at 3600 ft. elevation.

[pggg]

I get the impression mac 4-1 's are inefficient systems(cheap and nasty). Reckon you'd be better off with a quality genuine performance 4-1, K&N, and drilled airbox.

[MAXIMAN]

I don't know of many other 4-1 exhaust for the xs/xj11. Jardine maybe? I've never heard anything bad about Mac. I think Bob Jones uses them on his "re-builds" with good results.

As as far as the 140 mains. That sound a little big....especially in "Armadillo" chevy45412001 said 137.5 were a little big for his XJ. He indicated his plugs were still a bit sooty and he's at about 1000 feet or less.

Your at near 4000 feet. I would guess 140 would really foul.

My XJ runs a little lean with the stock 112.5 jets. I am at 950 to 1000 feet here in central OK. However when I tripped back home (west Texas) I was at 3000 to 6000 feet and ZIlla ran fine up there. I'm keeping mine jetted right where she's at because when I road trip I usually go up (read mountains).

[pggg]

I heard that if a 4-1 doesn't taper between the collector and the muffler then it wont be any good for extra power and will most likely be somebody's shifty quick buck noisy system that cunningly gives a false impression of speed.

[flb_78]

I know that the MAC exhausts arent the most notable for performance gains, but the price was very good on ebay from the Dennis Kirk store. Bought it 2 years ago and ran it for about 4 months before I blew the trans up and let the bike sit for a year and a half, but while it was on there, I had very bad low end and midrange. Went up 2 sizes on the mains I believe. Right now I've got the indy pods with factory exhaust that I've drilled out (sounds good), and it runs really great. Pulls real good till it hits about 3 grand, when it hits 3 grand, hang on. I'm too heavy for this bike, but my friend hit 8600 Rpm in 5th gear on it yesterday, fastest it will go with me is about 7500 right now. Since I've spent the money for the 4-1, I'd like to put it on, but I dont wanna lose alot of bottom end though.

[pggg]

flb, going up one size on the pilot jets to richen the bottom end might make all the difference on that 4-1? A 4-1 system laying around collecting cobwebs seems a waste.

[chevy45412001]

raise the needle

the single best fix i did to my XJ was to raise the needle. All the older xs's have adjustable needle positions ,not the xj. A good bike mechanic gave me theese tiny lock washers that fit the needle perfictly.(first i had to squeeze them flat) then put them under each needle. Picked up the midrange noticeably! I've even been told my bike has better throtle response then a new crotch rocket. The washers can be bought at any hardwhere store, just take a needle to get the best fit. Worked for me

[tab1324]

Chev454 - raising needle

Chev,

I'm having a similar situation with my XJ where anything from 3500 rpms plus it screams but below, the response is a bit boggy. Not terrible but it would be nice to get the same type of pull your arms off pull in the low / mid range as in the higher rpms.

When you say raise the needle, I assume you're talking about the slide / diaphragm needle? How do you do it? I haven't had mine off for a while so I don't remember how they're set up but arent they fixed to the diaphragm? This is where you'd have to put a washer right, between the diaphram and the needle 'step'.

Can you shed some more light on this?

Tom B.

[pggg]

The circlip is tricky to get at but easy enough. I used some common el-cheapo circlip pliers, the type with interchangeable heads. Hold the heads with pliers. Maybe chev has a good 4-1 on his XJ. I had a 4-1 (XS11) where the headers collected was shaped like 0000. Looked smooth but gave no boost though. Bummer. They reckon four 0's in a square is better for extra grunt. And also the tapering to the can. And the right back-pressure among other secretive things.