?

[Guest]

Ok we all know main jets are labled in actual points of mm's but what are the pilot jets labled in. Fuel flow or size. As corrisponding jet drill sizes dont match. thanks

[Steve]

All I remember about that is that when comparing Mikuni and DynoJet numbers, one of them is the actual size, the other is the flow rate.
I just don't remember which is which.

.

[BassCliff]

Hi,

That's a good question. The Mikuni main jets are based on flow rate and the Dynojet sizes are based on actual size. I've found many sites quoting this information:

http://roadstarclinic.com/content/view/61/96/

But I haven't found any information on the sizing criteria specifically of pilot jets. I'm sure the answer is out there somewhere.




Thank you for your indulgence,

BassCliff

[7981GS]

Ok we all know main jets are labled in actual points of mm's but what are the pilot jets labled in. Fuel flow or size. As corrisponding jet drill sizes dont match. thanks

Good question.

Daniel

[cowboyup3371]

I've been asking the same thing and just found this on a Mikuni/Dyno Jet Conversion site: (http://roadstarclinic.com/content/view/61/96/)

DynoJet jets are marked according to the diameter of the hole in the jet .. ie: DJ150 = 1.5mm and DJ175 = 1.75mm.
This is not true for Mikuni or most other OEM equivalent jets. This size Mikuni jet, (N102.221 Super BN), is marked according to its' flow rate, ie: 150 = a rating of 150 cc of fuel per minute.

I'm still checking to see if I find anything different.

[KEITH KRAUSE]

Ok we all know main jets are labled in actual points of mm's but what are the pilot jets labled in. Fuel flow or size. As corrisponding jet drill sizes dont match. thanks

Sharpy, as said by others already, main jets are not "labeled in actual points of mm". Sizing is determined by flow rate in cc's per minute (Mikuni) or actual hole diameter (DJ). I don't see why pilot jet sizing would be any different.
One thing to consider if you go ahead and drill out the PJ's bore: will the increased bore work well in combination with the multiple aeration holes surrounding it that are still the original size? Before drilling, just check some larger PJ's and verify that the aeration holes don't get larger or more in number as the PJ size increases.
I've never drilled ANY jet so your question just brought the above to mind. I've also never compared the size of the atomizer/aeration holes before and I'm too lazy to go out to the garage and dig.
Probably a non-issue but worth a look?