59 johnson 10hp carb adjustment questions

Hello all.
My 59 johnson 10hp has had a full tuneup. New ignition parts, carbs cleaned and rebuilt, plugs and fuel lines. Pulled it bout three times and she started right up. Now I need to adjust the carbs. I have read stickys post on carb adjustment. Set needles to advised positions. The motor seems to idle fast. If I turn tiller down lower then the shift mark, it dies (idle too slow). Tried to adjust carb (slow speed needle) to sync with slower idle better. Can't get it to idle down. Adjusted cam under flywheel. Not really helping. Should I have the motor completely parallel to the ground when adjusting carbs? It tilts a bit when in the water bucket. Maybe affecting the float? Also should I adjust this in neutral or in a forward gear? Frustrated. Any advice would b appreciated.
Thanks in advance.

Re: 59 johnson 10hp carb adjustment questions

Sounds to me like you're running it a little lean which will make the motor run fast then quit. Try turning the slow speed needle to the left (open) about a half turn (or so) and see if that helps. Also, having a slight tilt in the motor won't effect it at all. When you adjusted the cam roller, does the throttle plate start opening at the same time the roller hits the hash mark? It's supposed to.

Re: 59 johnson 10hp carb adjustment questions

Adjust it as it sits,as long as its upright,The air fuel mixture is touchy dont think in 1/8 of a turn 1/16 some times its just a tiny twist on that needle,Once the air fuel mix is to your liking,the idle adjust screw should be set it has nothing to do with air fuel,just RPMs

Re: 59 johnson 10hp carb adjustment questions

Yes. The cam adjustment is pretty dern close. As close as I can get it anyway. I will re-check that tonight. I adjusted the low speed way out (counterclockwise)as I was testing yesterday. As I decided I was doing something wrong, I stopped and reset the initial settings to start over. Im an outboard newbie and was actually just glad it started at all after giving it a complete overhaul! Smoked quite a bit too. 24:1 fuel ratio. Tempted to try 32:1 as I have read so much about this debate but decided to stick with what im confident wont hurt the motor.

Re: 59 johnson 10hp carb adjustment questions

Don't pay alot of attention to the "shift" mark. Those markings are very generalized at best. 24:1 is the correct ratio, I believe. You'll find that adjusting the carb while running in a tank will not be the same as when you have the motor on your boat and pushing. As long as you have it so it will start reasonably quickly and idle by itself (without tweeking it) you're very close to the finished part which should be adjusted on the water. That way you can adjust the high speed needle which will effect how you adjust the low speed needle.

Re: 59 johnson 10hp carb adjustment questions

Ok. I ill re-check the cam position. I messed with it some yesterday as I was not sure it was correct. Im a total newbie to all of this and was excited that it started at all after doing a complete overhaul for the first time! As I adjusted the slow speed (in neutral) it didn't seem to change the idle very much. I adjusted it so far out (counterclockwise)that I actually stopped and reset inital settings to start over. Motor was smoking pretty bad. I mixed 24:1. Thinking about 32:1 but not sure I should mess with that just yet. Got some oil around plugs in the back after all was said and done. Hoping I didn't foul the plugs. Argh. Frustrated. When adjusting the carb its about the smoothness of the idle not necessarily about the idle speed right? Assuming its not running wild or anything, which it isn't.

Re: 59 johnson 10hp carb adjustment questions

Also thanks for the quick reply guys. Very helpful.

Re: 59 johnson 10hp carb adjustment questions

Yes, it's all about smoothness and active responce to the throttle. Just be patient, it'll be well worth your efforts when you're out fishin' and it's running like a your watch.

Re: 59 johnson 10hp carb adjustment questions

HI fishindad. You may also need to adjut the idel set screw at the base of the vertical throttle linkage. By screwing it in the timing is advanced slightly and the rpms increase, by backing it out it the rpms will drop. Try to find a balance between turning the carburetor screw in to raise the rpms and backing the idle set crew out to lower the rpms. Between the two you should be able to dial in a nice idle. Here's a pic of the idle set screw on the side of the motor. Good luck. Keep us posted.

Re: 59 johnson 10hp carb adjustment questions

Thanks. I will look into that as well. This motor sat for over 15 years in someones old shed before I bought it. By the look of it it has not seen too much action for a really long time. After the rebuild I have tried to keep as much of the "adjustable setting" things as close as they were before under the logic that it ran good at some time. As I think about it more, maybe it didn't run and that's why it was put away. Judging by the condition of the coils when I purchased it, there was no way it could have been run much if any. Anyway, I appreciate the advice everybody.

Re: 59 johnson 10hp carb adjustment questions

stick with it. your patience will be well rewarded. once she's running again you'll be fine for many more years.