1985 XJ700n stock jets

Looking for a stock jet kit (107 main, 36.5 pilot) for my XJ700n. It currently is running stupid rich, it won't even rev with the air box on but loves air filter material zip tied over the intake. At idle it chokes on fuel or hangs till it burns the extra. Could I get away with XJ650 stock jets (110 main, 40pilot) here on the Florida coast?

I believe the stock jets in the bike have been drilled out bigger because the air jets are clean. 200 main air, 70 pilot air.

 

Talk to Len at XJforever in upper right corner he will get you a what you need

 

are the air jets on the top of carb under diaphrams reversed? Main AIR Jet Size: #70 Pilot AIR Jet Size: #210




XJ700 Models:

Years & Models: 1985-6 XJ700 air-cooled models
Carb Manufacturer: Hitachi
Carb Series: HSC33
1985 Carb Model ID: 1FG00 (N models) or 1JJ00 (NC models)
1986 Carb Model ID: 1NH00 (S models) or 1NK00 (SC models)
Main FUEL Jet Size: #107
Pilot FUEL Jet Size: #36.5
Main AIR Jet Size: #70
Pilot AIR Jet Size: #210
AIR COMPENSATOR Jet Size: not used
Starter FUEL Jet Size: #36 (non-replaceable, in float bowl)
Main jet NEEDLE ID: #Y-20
Main needle JET Size: #3.2mm (the main needle JET is also known as the "power valve" or "emulsion tube").
Fuel Level in float bowls: 1.0mm +/- 1mm (.039" +/- .039")
Idle RPM's: 1,050 rpms

 

When is the last time the carbs were completely stripped down/ cleaned; bench synched, color tuned and running synch performed?

I do NOT know how to verify jet hole sizes, but it is possible you have the correct jets in there and there is a different condition(s) that is creating the 'stupid richness' you outlined above. Hopefully someone will tell us the correct way to verify those itty bitty holes . . . . guitar strings? small plug gauges? cat whiskers? R.C.H.'s?

 

^^^^+1 agree with stumplifter ...if your carbs are out of synch can cause problems.

 

FYI the way to verify jet sizes is with a indexed metric wire set, or (if you're careful) an indexed set of metric drills. The size stamped on the jet is the hole size in hundredths of a millimeter (your 40 pilot is 0.40 mm)

 

When I got my XJ700 it was running very rich also and I got about 27-18 mpg and would foul plugs within a week or so. It had a foam UNI filter and a standard air box. The jets were stock but the pilot screws were way out in order to compensate for the increased air coming through the foam filter. To make a long story short, after getting the carbs cleaned including new needles and seats and properly set float levels, valves adjusted, and installing a stock paper filter I used a colortune plug to get the proper setting for the pilot screws. I now get approx 41-42 mpg on the road and about 40 mpg overall. The colortune procedure I used was to close the pilot screw until I began to get a white flame--or lean mixture, then open the screw until I had no white. After doing that for all for cylinders I installed new plugs (easier to read new clean plugs) and rode for about 20 miles and checked the plugs. I was looking for a light brown color. I adjusted the pilots by opening them about the width of a dime and rode and checked them again. I did this over a couple of weeks until each plug had a nice light brown color. The bike starts almost instantly, idles well and runs great. By the way, I think all of my pilot screws are between 1 1/2 and 2 1/4 open at most. One other thing-- I set the floats at the low end of the range but made sure they were within specs.

 

Tabaka - whilst adjusting your colortune was that at idle that you went from white to blue?

 

Also, if the slide needle is worn, or the emulsion tube is worn where the needle goes into it is worn, it will run overly rich, too........

But, I would start at carbs first----

 

Yes. When I was at idle when I closed the pilot screws. Initially I had them set at the 2 1/2 setting which gave me an all blue flame. However, I have found that the "blue" flame is found over a fairly large range of the pilot screws. As I closed the pilots and approached a setting of approximately 1 I began to get a lot of the white flame. That's when I began to open the pilot screws until I got a steady blue flame and then began the process to tweaking it to get the final setting.

 

And THAT, ladies and gentlemen, is how you do it

 

Nothing better than hogfiddles' confirmation.

 

Except getting him to do it for you!