1vj carb. Best jetting for Europe. Anyone improved on standard?

[donnybach]

Hi all. I put my carbs back to standard jet sizes recently (46 pilot, 145 main, needle on middle)and it meant I could drag my revs down to less than 1900/2000rpm while riding, and pick up cleanly from there which she ain’t done in years (had 48 and 150 jets in before and she was sluggish below 2500)., which is nice. Now it’s got to sub zero I find a little lean stumble on a throttle blip from idle so might put 48 pilot back in if I can’t open the pilot screw out any more( on 3 1/2 now. ) Before I pull the carbs off again, has anyone successfully benefited from putting a larger jet in the second carb, to keep the left one stock to look after low running? It’s 125 as standard. She feels like she needs a bit more at the full throttle. It’s either that or I try the 150 main again in the lefty. I’ll be rebuilding her engine this year and want the fuelling sorted first so I’m not messing around with it after. Thanks . Donny

[donnybach]

Well she sailed through the mot, after I delayed it when I noticed fuel pissing out of the carb. I’d put all back to standard, but raised the fuel level (too much). I reuse bowl gaskets while adjusting the jets until I’m happy. 40 mins before mot and the tank, airbox and carbs were back off. Took the opportunity to put the 48 pilot back in. Dropped float to 26mm, 145 main. New bowl gasket. She runs like a dream. Low speed and high. Well made up. Just needs some nice new springs next.

[jibber]

That's all worth noting

[donnybach]

Ok so I bought a 6sigma jet kit. Thought I’d add some info for anyone thinking about it.
Most of it is unnecessary as you can get the jets at a dealer but I’d thought I’d use their experience to see what their best recommendation was. Kit included the two main jet sizes,(actually low and medium jets) shims for needle height (not needed), two drill sizes for the cv jet, and drill for the cv slide hole. Oh and a pilot jet (not standard tekei type but size 52, can’t see it idling well on that). The kit is ok but the main jets are 140 and 145. I already have the standard (145) fitted, the bigger jet for 1vj (in the manual) is a 150. So no gain there. I’m only altering the cv carb for now, as she’s already quite well set up at idle, and low rev running. She just needs a bit more pull at fun throttle levels.
Their instructions are a little generic and they don’t really follow their own order of operations. I lifted the cv needle one clip to start. Bike did have a little more pull at full throttle. Then I drilled the cv jet hole to first size. Again it was slightly better. Next I’m drilling the cv slide hole. I’ll note any differences as I go.

[jibber]