Lean miss Q on `67 johnson 9.5

[ultra353]

Just picked up this `67 johnson 9.5 in fantastic condition for next to nothing. No spark on one cyl, - fixed that easily, dirty carb,- went through it got it clean including idle circuits, feels like it has good comp as compared to my `68 9.5 i had( gauge is on loan haven`t got it back yet). Starts up with 1 pull and idles smoothly with the hood on, take the hood off and i`ve got a lean miss. Put it back on idles great, i`ve never had this condition before.
Is it inhaling its own fumes with the hood off to give me this cond, or possibly a small vaccuum leak somewhere and running it with the hood on cuts down on the amount of air thus giving it the correct air/fuel ratio? I haven`t had time to look into this and i might just leave it along as idle fine with the hood on. Any thoughts?

 

[Daviet]

Re: Lean miss Q on `67 johnson 9.5

Shouldn't matter if the hood is on or off.
Where have you got the low speed needle set, you might open it another 1/4 turn and see if it helps.