Mikuni jet sizes in mm??

[bladerunner]

I'm looking for a mm size to compare mikuni hex jet sizes in MM. yup I went cheap and got a "200-300" 10 piece jet kit from ebay on the listing they were stamped 200,210,220 etc however when they arrived I had no stamp..even better they were not all different ie 2 or 3 of the same sizes!! Anyhow I got my money back and they didnt need them returning so I'd like to have a ball park figure if anyone knows the actual diameter of given sizes? I know the test and flow procedure and indeed the differences for the same size due to finish etc but hey I'm up jetting so thought I'd ask as no actual jet size requirement is known until I do some testing so a ball park figure would let me try these jets if I know the 210-240 sizes for a std genuine mikuni but I'm struggling to find any info on the webs!
____________________
Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

[ThatDippyTwat]

AFAIK, Mikuni and Keihin label in .01mm increments, so a #200 is .200 mm, #240 is .240 etc.

You may get some very small pin gauges cheap if you're lucky, but a new, calibrated set will (probably) cost more than the carbs the jets are going in.
____________________
'98 VFR800 (touring) - '12 VFR800 Crosrunner (Commuting) - '01 KDX220 (Big Green Antisocial Machine)

[bladerunner]

thanks for the reply there TDT but thats not correct. a #200 jet is deffo a lot larger than 0.2mm..at least for the long hex type anyhow
____________________
Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

[sickpup]

I know the different types of Mikuni jets are measured in different ways but iirc the round tyoe are measured as how many cc's of fuel they pass from a 50cc head per minute.

[ThatDippyTwat]

Goes to show. I was told this when I was an apprentice, *many* years ago.

Turns out it's shite. You learn every day.

https://i.imgur.com/brAJrU6.jpg
____________________
'98 VFR800 (touring) - '12 VFR800 Crosrunner (Commuting) - '01 KDX220 (Big Green Antisocial Machine)

[Pete.]

You don't need an expensive tool to measure jet sizes. You can do a very good job using basic tools with a little thought. Here's how I did it when I was making up some jets for my mate's BROS.

*Get a jeweller's screwdriver - the cheap all-metal ones with the little spinning top.
*Grind a very shallow taper on it down to a point. I used a bench grinder with a fine wheel and put the screwdriver in my battery drill on slow speed to make sure it was round. You just need a gentle touch to get a nice finish, or you can use fine emery to make it smooth.
*Use a permanent marker to paint the taper black for each measurement.
*Put the tapered needle in the hole and gently seat it and give it a little turn.
*When you remove the tool there will be a shiny ring in the black. *Measure the taper at that point with digital calipers. That's your hole size.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[bladerunner]

[bladerunner]

ok I measured the main jet fitted..which being a different carb and std looking motor I got from Scotland a few years ago actually had a 230 main jet already fitted ..measured 1.28mm so I've put in a 1.48mm just to be safe! its a 12a UK restricted carb and the last RD125LC I jetted was a 10w or the full power model....so it wasnt the 155 main I was expecting to find but hey better safe to start with as no airbox and running a 350 lc Allspeed at least having a 230 size to measure means I know I'm in the right ball park
____________________
Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's