Jet Sizes

[RobGS850L]

The carbs on my 1100 needed some cleaning and was trying to I.D. the jet size. No imprint on them soooo...... My next question is where do I find a reference to the size of the opening? Are they 1000's of a mm. or something? Next thing that will be fun is to actually measure it. :roll: I figure if I at least know what the hole size is then maybe I can get a drill or something to compare it with. Any help would be mucho appreciated.

[robinjo]

Mikuni jets are in 100th's of a millimeter so if you have a jet #100 it is a 1 mm inner diameter. I think you have a 107.5 main jet but I'm not 100% sure. It should be on there if it is a stock jet.

[RobGS850L]

Thanks. The bike was modded before I got it and that was one of the other reasons I was cleaning the carbs out. I kinda' was curious what was in there. Thanks for the info and I'll now know where to start.
Now to the conversion chart. 8O
Danged metric to inches crap.

[Clone]

Man-o-man are you guys afraid of machine shop people or what! When I want to measure something or check the size of a jet, I take it down to the machine shop/ machine tool depot and either have them measure it or borrow the feeler and measure it myself. They are usually pretty happy to oblige. I usually spend a couple of minutes plugging different drill bits into a jet until I get the size narrowed. If I want to be real exact I use a feeler.

[saaz]

Yep, straight metric is far easier! Even if the jets had a size on them I would still measure them as I have had jets drilled out when fine tuning jetting, so the stamp was not the actual size. Any carb place should have the right drills to measure with. Just to add to confusion, jets by different manufactures are sized differently...what fun