1983 115 inline mer, runing

[Charlie61]

hello again just got motor running after replacing almost all electrice parts . starts normal, can put it in grear still runs normal. When I go to throttle up it dies . So I throttle very slow and let it run there about 30 sec. the rpm will go up. I keep doing this untill I get in to a higher rpm and will run great. if it had wings it would fly. if I throttle up faster and hit the chock as I'm going higher it will work and run great at hi rpm.
This is telling me it needing more fuel in throttling up!
I did timing by the manual it did not work for me to will.
I like to know if I could ajust the carbs, or ajust the linkage going to timing, which do you think would work ?
Thank again

 

[CharlieB]

Re: 1983 115 inline mer, runing

Idle mixture is too lean. Idle mixture must be adjusted richer than "Best Idle Speed" in order to provide the additional fuel necessary for crisp acceleration.

How long has it been since the carbs have been cleaned? It is often a waste of time trying to adjust dirty carbs. If the carbs haven't been cleaned in a long time it may just need cleaning, if so, be very careful and turn each idle mixture screw IN until only very lightly seated while COUNTING the exact number of turns and writing it down as once finished with cleaning and replacement of gaskets and needle/seats you will want to return each idle mixture screw to the exact position it was in originally.

 

[Charlie61]

Re: 1983 115 inline mer, runing

less an 6 month ago I rebuild cards . and it take some time to get them ajusted. the mixture screws counting was very hard going they are at about 1 and 1/4 turn not 1 1/2 . but it idle good.
there is an ajust at the top of the cards which is going to the timing linkage, do you think this is a good place to ajust idle speed?
thanks

 

[Georgesalmon]

Re: 1983 115 inline mer, runing

No, the idle "speed" is adjusted by the idle screw on the main throttle. The idle mixture is adjusted on the carbs. You may only need to back out each idle screw on the carbs an 1/8 of a turn or so. Do this an 1/8 of a turn out on all carbs then try and accelerate if good great. If not the another 1/8 of a turn and try again, and so on. When you get good acceleration stop. If the carbs are clean and working properly you will get to where it idles OK and also accelerates good. You need to do this on the water not on muffs.

Edit: be sure and back out all three idle screws at the same time and then try acceleration, then all three again. Don't do one carb at a time.

 

[CharlieB]

Re: 1983 115 inline mer, runing

Idle speed is adjusted with ignition timing, a screw on the throttle lever pushes against the timing lever to advance timing and increase idle speed.

At idle all carbs should be fully closed, idle mixture is adjusted with the idle mixture needles/screws and set while the boat is IN the water and IN Forward gear. This is critical as exhaust back-pressure and engine load make a major difference in fuel requirement at idle.

Once idle mixture is adjusted to 'Best Idle Speed' IN gear and IN the water, idle mixture must be adjusted even richer to provide the additional fuel necessary for crisp acceleration, often near 1/4 more turn out on each idle mixture screw. Make small increases in idle fuel and test acceleration, any hesitation, cough, sneeze, or bog, prove a need for more idle fuel. Make another small increase and retest acceleration. Repeat to perfection. Then make final idle speed adjustment with the idle timing, still in Forward gear.

 

[Chris1956]

Re: 1983 115 inline mer, runing

Just to be clear, The timing must be synchronized to the throttle opening. There is a timing specification for when the carbs just start to open, called "idle pickup timing". The idle speed timing is usually less advanced than the idle pickup timing, giving less RPM. The idle stop screw is adjusted to set idle speed. Max spark advance is also set and locked in.

 

[Charlie61]

Re: 1983 115 inline mer, runing

thank 's it's starting to get the picture. thanks again you gi are great. it's going to be a day are two before I got it back in the lake. I'll post the ajustment then.
Thank and have a great day Georgesalmon,CharlieB and Chris1956

 

[Charlie61]

Re: 1983 115 inline mer, runing

Hi it's been a some time been little ill getting better and will do ajustment as soom as is get above 70 have in sunny Fl. Happy New Years

hello again just got motor running after replacing almost all electrice parts . starts normal, can put it in grear still runs normal. When I go to throttle up it dies . So I throttle very slow and let it run there about 30 sec. the rpm will go up. I keep doing this untill I get in to a higher rpm and will run great. if it had wings it would fly. if I throttle up faster and hit the chock as I'm going higher it will work and run great at hi rpm.
This is telling me it needing more fuel in throttling up!
I did timing by the manual it did not work for me to will.
I like to know if I could ajust the carbs, or ajust the linkage going to timing, which do you think would work ?
Thank again

 

[tazrig]

Re: 1983 115 inline mer, runing

Good luck with it! Thats a classic engine.