Non-adjustable pilot mixture screws on KZ750n?

82-83 kz750n versions have non-adjustable pilot mixture screws according to the manual. I am puzzled, because I though I would have to adjust these.

they are covered by a small welsh plug on smog controlled bikes all you need to do is drill out the center of the plug with a small bit then screw a small sheet metal screw into it and grab a hold with a pair of pliers the pull it out. the fuel screw is located underneath the carb on the intake manifold side. then adjust away as required.

Then why in the world would the service manual say non-adjustable? Don't you find that odd?

they are non adjustable until you pull that welsh plug they did it to prevent people from making changes that could affect emissions.

Alright...another question...I should turn the pilot screws in and count the number of turns right just to get an idea of the factory setting I assume?

Also I've been advised to adjust the mixture screw on each cylinder until I get the highest reading for each cylinder on the carbtune pro. Does that sound about right?

Not sure how I am going to drill the ones in the middle to get to the pilot screw, as the carbs are on the bike.

turn them in until they lightly seat not any more than that as you could damage both the adjuster and it's seat. make sure you record how many turns in. stock setting should be 1 1/2 to 1 3/4 turns that should be a good place to start. i have nevr used the carbtune myself i have always used motion pro manometers or gauges my self so i'm not sure what procedure you would use for it .what i can tell you is this turn each screw out the same amount until it runs as smooth as it cando you have different filters and pipe or any other mods or is it stock.

Good experienced advice...

Stock air box but I did put a K&N air filter in it.

The manual says they are non-adjustable because the EPA in the US, bans the manufacturers from making the mix adjustment accesible to the citizens, who otherwise might be tinkering and polluting all over.

The manufacturers simply epoxied a cap on the screw wells and called them non-adjustable. You are not supposed to know there are screws under those caps. That is EPA state secret.

I've never used the carbtune, but might be a good idea as basically is a spark plug that reads the mix, and can tell you right away. Other wise, as there are four carbs, you have to adjust by seat of the pants, assuming all carbs are perfectly identical. Then you have to check several weeks later see how your spark plugs are looking.