New member with an old XJ needs help

Good afternoon everyone. I’m new to the site and hope to add plenty to the discussions. I am a former BMW owner/weekend-wrench who is now tooling around with an 85 XJ-700 Maxim-X. I was out of the cycling scene for years, but could no longer stand it. I traded an old mountain bike for the XJ with a buddy of mine. Difference is, he was able to go riding the minute I gave my bike to him and I was stuck with the poster child for troubleshooting. Nevertheless, getting this bike in top-order has become a borderline obsession. By the looks of some of the posts on this forum, the XJ’s have a way of tantalizing new and old owners alike. By the way, did I mention the bike had been sitting, untouched, in a garage for the last six years? Gulp!
It’s been about a month now. New tires, battery, brakes, grease and so on. I believe in disconnecting and reconnecting all electrical connections in an effort to establish new contacts; so I did. All of the fluids have been replaced, including new filters, i.e. air and oil. I flushed the fuel lines and gave the tank two coats of Kreem. Rebuilt the fuel petcock and carbs with aftermarket rebuild kits and threw everything back together. Now, I’ll be the first to admit there’s no substitute for tuning the carbs with a ycis tool and a the vacuum gage. I’ll get to that sooner or later, but I figured bench-syncing the carbs would be a good start. To make a long story short, this is what I am currently running into…
*When I remove the vacuum plug from the intake manifold (tube between the carbs and the block) on the #4 cylinder, it increases its idle by 1K rpm. None of the other ones do this. Note-I gave some intermittent shots of engine starter in the areas where leaks are typical (increase in rpm in the event of leak), but couldn’t find any.
*The petcock is functioning properly. So then why is it that when I attempt to prime the carbs, no fuel is seen flowing through (I have a clear inline fuel filter). There are no kinks. The only thing I can think of is that the floats are doing their job, thus not allowing any flow to pass. On a side note… when I manually flush the line with fuel, I get air pockets in the inline filter that eventually fill the entire line-causing the bike to run out of gas. Does it matter that part of the line is elevated above the petcock before it reaches the carbs?
*How is it that I can get the proper primary coil resistance (2.7 +/- Ohms) but absolutely nothing when measuring the secondary (12k +/- Ohms). Any tricks here.
That’s it for now. In the interim, I have an original service manual for the XJ700XN/XNC. Feel free to shoot me an email in the event you need anything from the book, i.e. torque specs, resistances and so on.
Thanks in advance.
Jay

 

welcome Jay,,,

let me break it down for the pro's so they can read it better,,,,it's morning for me drinking my coffee so it maybe just me
,,,,4 vacuum ports #3 has the vacuum hose for the operation of the vacuum operated on off valve,,there are three positions on, res an pri,,,prime is the 1 you want to get things going at first,,,,an when you pull the plugs off you only get an increase on #4,,,,

do you in fact pull vacuum through the other 3?

clear filters are famous for fooling you that there's no gas flowing when there is so,,,,

is there any gas in it it may have some air also,,,,I supect the fuel hose routing myself I did this on a bike once it didn't like it either I put it back,,,,,,yes I think routing it so the air flows up does make a difernce

on the secondary's each coil has 2 wires coming out ,,,the only posible problem I can see is if you grap 1 wire from each coil,,,,there will be no reading,,,,,,

welcome to the site I can't say it enough these guys are great,,,,obsession I'll have to look that word up later,,,I don't think any of that goes on around here,,,,Dan

 

Okay, now I'm confused a bit. The engine revs faster when I pull the cap off of the one closest to the rider's right leg. Based on your comment, I guess that's the number 1 carb? Yes, I am getting plenty of suction from all four. I'll cut some hose so the only direction for the fuel is downward. Can I tell if there is fuel in the filter? Definately. It gets the fishbowl effect and the filter element looks twice as big when there is fuel inside. Here is something else I ran into. The screws on top of the carbs, which are centered on the intakes (recessed brass looking) are all out of whack. Is there a basic setting for these, i.e. two turns from being seated? Thanks again.

 

#1 is on your left sitting on the bike ,,,,,,,fuel coming out of the vacuum ports is not right so I will default to the pro's here as I need to go to work ,,,,I sort of sense we were not on the same page here,,,you'll get help soon

 

Those recessed screws (I believe they are the pilot screws)control idle air-fuel ratio.Gently screw them in so that they seat,then back out 2-1/2 turns.There are threads here which will help in fine-tuning their exact positioning for your machine.