Mikuni tuning issue.

[Crab]

What causes slight sputtering off idle, as the low speed adjuster will tune the idle just fine. It only sputters till about 1/4 throttle then is fine. Also, if the boat is on its left side it has a tendancy to go rich and die. The jets would be to the hull side, and the fuel pump to the engine side.

 

[Scorn800]

Are these the 40i carbs?
if so the fuel pumps should be to the outside

 

[Crab]

No, 44 Mik.

 

[#ZERO]

I have the same problem with my OEM 44's and it's the pop-off pressure causing it.

What's your jetting at?

 

[Crab]

The high is 170, not sure on the low jet or popoff. Does it sound to low?

 

[adet16v]

I have the same problem with my OEM 44's and it's the pop-off pressure causing it.

What's your jetting at?

I have the same problem on my boat, (mikuni SBN 44) when its on its left side (carb side up) not so bad that it dies, but it does richen up a good bit that I need to clear it out

 

[Matt_E]

What causes slight sputtering off idle, as the low speed adjuster will tune the idle just fine. It only sputters till about 1/4 throttle then is fine. Also, if the boat is on its left side it has a tendancy to go rich and die. The jets would be to the hull side, and the fuel pump to the engine side.

The low speed adjuster is for tuning idle mix, not running condition - though it can be used as such. (But shouldn't)

My guess is your popoff is too low.
The side issue you mention would support that notion. Up that popoff pressure a good amount, richen the pilot (to compensate) and see how she does.

 

[Crab]

Next time I pull it, I will post the current n/s and popoff with jetting.

 

[sjetrider]

Shouldnt these carbs be run w/ fuel pump to hull side????

 

[Matt_E]

They can be run either way.