"lightly seated?"....

[ross]

hey there folks...was just wondering....has anyone exactly determined what lightly seated is?.......i know about turning them in until they are "lightly seated".....but where is that?......i was wondering if someone could tell me from having the idle screw removed completely, back threading it until the threads line up.....then counting the turns in until you get "lightly seated".....i know the spring should not be fully compressed, but if you have something in the threads that would make it hang up and feel "lightly seated", then you would adjust up from there...god help ya if ya break the tip off......haven't been there and don't want 2 b...but how can you tell if you are truly "lightly seated"?......thanx in advance for the response...ross

[boyat68]

ross:

On my 80G, I took the carbs off and examined the inlet of the front of the carbs where the tower of the screws sit. I noticed a small (very small) hole where the screw tip seemed to go. Feeling with my finger tip there was nothing protruding into the inlet. I then drilled the top of the cover and used a sheet metal screw to extract the cover as suggested on this site. All of the covers came off with very little trouble. I then carefully removed one of the screws counting the number of turns that I backed it out. ( I do not remember the number now as that was a couple of months ago.) I then examined the screw tip, washer and spring as suggested by the site Gurus. I then returned the screw, washer and spring to the hole of the Air Tower, screwed it down to the approximately starting position. I then screwed it further holding my finger over the hole. I continued down until I felt the tip protude from the hole. I then went a little further untill I felt the slightest resistance on the screw. Now I knew what it felt like to lightly seat the screw. I did the same on the other three screws. I now had experience on "lightly seated." Since that time, having removed the carbs thirteen times, and starting the adjustment over and over I now feel that I have the process down cold and can repeat lightly seated with out any fear.

[Ken Talbot]

Good idea there, boyat. When they break they are always protruding well into the throat. Catching it on your fingertip, then very carefully taking it a bit further to detect the resistance is excellent technique.

[prometheus578]

"Tip tips."

Lightly seat is just as Boyat mentioned... gently, till you feel slight resistance.
Now then, Boyat has the later style carbs... they have a stepped design to the pilot screw.
The early carbs have just a tapered point, quite sharp. It is these tapered screws that wedge themselves into the hole and snap the thin points off.
I don't believe anyone with the stepped design has ever broken a tip. The tip fits in the hole nicely.
The taper tip will continue downward till it gets too wide to go any further (slight resistance)... unless you try to force it, and then it breaks.

[81xsproject]

While I have carbs on the bench, I very carefully find the lightly seated position. Once I seat all the screws, I use either a sharpie or a small punch to make marks on the towers that line up with the slots in the mixture screws. That way, next time I want to lightly seat the screws, I can anticipate at each half turn I might be approaching the lightly seated position. It is also nice for setting the screws a certain number of screws out.