Danno's 465

May 18, 2013
Hi there,
Got an '82 Yami IT-465. I rebuilt the Mikuni VM-38SS carbie; replacing all the pitted brass from decades of neglect from the previous owner. The only part I could not get my hands on was a stock 6F39-4 jet needle (can't find any data on the 6F39-4). I currently run a Q-2 needle jet (also called a MAIN NOZZLE) and the dealer advised a 6F16 jet-needle to team up with my Q-2 needle-jet.

Now, after modifying the clutch components to that of an '83 IT490 (the 82's had a pressed start-gear behind the primary, which was notorious for spinning out and breaking/jamming stuff), I her finally got it started and running. Ran it through all the gears, with stock carb settings (#40 pilot-jet @1.5 turns of the air screw and a #390 MJ). I observe that it appears to be running rich (gurgles quite a bit, during steady 1/4 to 1/2 throttle. I have run the air-screw out to three-turns without much difference.

My questions is these:
For YZ/IT-465 applications, do a Q-2 needle jetand and 6F16 jet needle pair nicely together?

How does a 6F16 compare to a 6F39-4 jet needle?? (richer leaner?)

Is there better choice of size of needle, for a 6F16 OR a better choice of jet needle for a Q-2?

I only plan on running on the fire trails and stuff. No comp or racing for this old bike. I just want to get rid of the gurgles. I do plan on trying a #380 and #370 MJ, to see if that helps... But I would like to FIRST ensure that my needle-jet / jet needle pairing is optimal. Any help is appreciated.



Jan 27, 2000
Danno. Check out www.sudco.com for information on jetting. They will have charts that you can use to compare jet sizes. They also have parts for vintage carbs.
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