Low RPM's in neutral / idle, stalling

[Sureshot]

Hey guys,
Trying to get this Johnson 50 HP outboard idling better. Model # is J50PLSSM, year 2000. So I'm supposed to get 1200 RPM's when it's sitting in neutral but I get way less than that. To get it running I have to warm it up, take it back to neutral and then quickly shift forward and give it some throttle. I just need it to run better in slow speeds and neutral. Carbs were rebuilt. Link & sync done. Mixture screws set to 3.5 turns out. Any suggestions?

 

[fishfeatures]

Re: Low RPM's in neutral / idle, stalling

try turning in the idle screw where the cable conects up to the throttle arm.turn 1/4 at a time to see if increases the idle rpms a bit.

 

[Sureshot]

Re: Low RPM's in neutral / idle, stalling

Thanks fish. I have adjusted that screw some but it never seems to make much difference, will look at it again though. If the RPM's are too low in neutral it seems like the only adjustments would be that screw or the mixture screws, correct? Also worth noting, the motor shudders and shakes quite a bit at low speeds. Compression is 120 on both cylinders and good strong spark on both.

 

[fishfeatures]

Re: Low RPM's in neutral / idle, stalling

make sure the cable is correctly adjusted, remove it from the stud and it should line up with it without having to push or pull the throttle arm. If adjustments need to be made use your thumb to adjust the trunnion nut (plastic adj nut on the cable at engine). Rule of thumb for setting the mixture is to back out each screw about 2 - 2 1/2 turns then turn in 1/4 at a time and when the engine starts to splutter just back it off a bit and it' here you'll find the correct mixture setting.

If you are still getting trouble after that , come back and we'll try something else.