TOPIC:

Does turning the air screw in make leaner or richer? Im guessing leaner because of less fuel flow

General rule of thumb- if it is "upstream" of the carburetor (between the carb and the airbox) the screw controls air. If it is "downstream" of the carb (between the carb and the engine) it controls the fuel.

That being said, the screws on these carbs control fuel. In is leaner, out is richer.

Is it a secret which air filter system you are running or do you just not want to share ?

If your air intake system is too restrictive it will OBVIOUSLY lower the air to fuel mixture and make it run RICH.

The standard Z1300 air filter and filter box restricts air flow making them run rich.

Thats whay I asked the question days ago..........but no reply yet ?

Pete F
UK

I run a stock air boxer with a replacement air filter from uni filter. Sorry I didn't reply to this question sooner. It runs the 105 main 45 pilot. I either want to change the airbox or jet with 100 main and 42.5 pilot. Please tell me what would be a better route?

A lot of carb model Z1300's had rich running problems from new (or in the UK they did) and Kawasaki had various "mods" to try and overcome it.
One of these was to run the bike WITHOUT the top aor box cover / tool tray under the seat, which allowed far more air into the mixture.

This did have a positive effect in some cases so is worth a try.

Other mods were to cut off the airbox intake "Trumpet" which if you look at it has a very small neck to feed 3 large hungry carbs.

I would try the system without the top tool tray or leave it on but remove filter element and just see if it has an effect.

THIS ADVICE IS GIVEN FREE AND FROM A KAWASAKI UK TRAINED MECHANIC (1977 TO 1982) WHO HAS OWNED OVER 10 Z1300's AND SERVICED AND REBUILT MORE THAN HE CAN REMEMBER OVER THE PAST 30 YEARS AND ONLY GIVES ADVICE IF HE KNOWS FOR 100% CERTAIN THE ADVICE IS PROVEN, TRIED TESTED AND RELEVANT.........IT IS NOT JUST AN OPINION OR SUGGESTION AS MANY OTHER (SELF TITLED EXPERTS) WILL GIVE.

Pete F
UK

If the engine is running rich right through the range and has stock jets or one size removed then the first place to look is the air feed.

Get a well used paper filter (because you will destroy it) and spray some WD40 or similar over the paper, just a light spray, and check for sections of the filter that have lots of dirt and sections that are still relativly clean. Most filters will have sections that have "dead spots" where still air means the filter is not being used well. I have seen this to a very limited extent on Z1300s but to a far greater extent on many other bikes. The worst by far is the a100 Suzuki and I had many owners come back after I had done my tricks and say that it was a totally different bike to ride and the fuel consumption had halved.
Some of the V4 Hondas we used to put an extra inlet to the air box which improved the top end no end.
Using an oiled foam filter will give the same results and show up dead spots.
If you are using standard size jets and fouling plugs because of over fueling then the jets are NOT the problem look further afield for the problem. Float heights or air restriction are two obvious places to start.