nissan nsf15b primary jet setting

[brokenwrist]

Hey guys, I have a 2001 nissan nsf15b engine. A couple years ago I had to pull the carb apart and clean it because it wouldn't start or wouldn't stay running. Found the carb to be pretty gummed up. I pulled the jets one at a time and cleaned them out, making sure that they were put back in the same out of turns from bottom as the factory setting. Anyway last year I loaned my boat to my friend to use for a couple of days, and he said the engine was real responsive after I had cleaned the carb and he redid it, and said he also readjusted the main jet. The problem now is, when I try to rev the engine from idle it chokes itself because it's receiving to much fuel at once. Does anyone know how many turns out from bottom the main jet should be set at so I can get this thing running right again If the engine speed is brought up gradually or the revs are done in short bursts it'll rev up just fine, just not from flat idle. I plan to pull the carb again and clean again anyway, I just want to make sure the main jet is set correctly. Thanks

 

[Scott Danforth]

so start turning it in until it runs right.....its called tuning.

 

[pvanv]

No, No. No. The jets are not adjustable. Period.
Look at the diagram. The jets must be seated all the way in the bores. If you are starving during acceleration, you are probably experiencing junk in the passages -- varnishing. The 15B is particularly succeptible to that, because the passage in the bowl that feeds the ABS and accelerator pump is low, and just running the carb out at the end of the day doesn't necessarily get the old gas out of it. You of course want to idle the carb dry any time the motor will sit for a few days, but in addition, open the bowl drain and let that last half-teaspoon out. The main jet seats against the emulsion tube nozzle; the slow jet has a rubber plug below it, so that it feeds through the main jet.

 

[Sea Rider]

We as others agree about runing the carb dry to avoid junk formations inside carb, in this particular HP model, would pulling choke out and in while throttling several times, will there be less fuel leftovers on bowl compared to simply let OB die of fuel starvation ?

At least on 2 strokes carbs find amazing how much fuel there's left inside carb when just letting OB die of fuel starvation after fuel line has been disconnected from carb connector.

Happy Boating

 

[pvanv]

Yes, playing the choke would help. So would operating the throttle, because the accelerator pump will then pump fuel out of the reservoir. Still best to drain the carb.