Slow speed needles 115 hp 1970

Storskar

Cadet
Joined
Aug 11, 2003
Messages
15
Should the slow speed needles be very heavy to turn. I got the feeling i would break them if i tried harder (at least two of them). Is there any stop screw i have to loosen first or...? Can they gum up totally?<br /><br />What happens if a needle is totally closed ?<br /><br />Thankful for any help!<br /><br />/Micael
 

ajp

Petty Officer 1st Class
Joined
Jan 6, 2002
Messages
280
Re: Slow speed needles 115 hp 1970

They should not be real difficult to turn. If the port is closed you will bogg down at throttle up. If the motor is running fine I would leave them be. If you have to buy them, the factory price at an OMC dealership it $37.50 each. I had to replace one because I dropped it and bent the point. The points are super fine(sharp). <br /><br />I have a 1969 115hp and am fairly familiar with adjusting these needles. <br /><br />Do you have an "original service manual". If not, I would suggest you go to EBAY and buy one. They are selling a bunch of the old service manuals and it is invaluable for knowing your engine.
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Slow speed needles 115 hp 1970

Storskar..... I suspect that someone may have coated the threads of those adjustable valves with locktite in an attempt to keep them from moving due to viberation. You may need to remove and dismantle them, then apply some heat with a hand help propane torch in a effort to loosen them should that be the case.<br /><br />The proper adjustment procedure follows:<br /><br />(Dual Carb V/4 With 4 (2 each carb) Slow Speed Adjustable N/Valves)<br /><br />The adjustment procedure of the carburetor slow speed needle valves follows. NOTE... if the needle valves turn too freely, replace the nylon bearing retainer (the nylon item at the front of the carb that the needle valve goes through first) with the newer type RED retainer #315232. If your engine has that weird linkage that connects all four of those needle valves, the newer RED retainers will enable you to discard that linkage. The RED retainers make it impossible for the needle valves to viberate out of adjustment. <br /><br />(Carburetor Adjustment - 2 Slow Speed Adjustable Needle Valves, each carburetor) <br /><br />Initial setting is: All (4) Slow speed valves = seat gently, then open 1-1/2 turns. <br /><br />Facing the carburetors, start with the top left needle valve, then the top right valve, then the bottom let valve, then the bottom right valve. It may be necessary to redo these steps to get the adjustments ideally set <br /><br />Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. <br /><br />Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting. <br /><br />Do not attempt to gradually adjust all four of the valves at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve. <br /><br />When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 

Storskar

Cadet
Joined
Aug 11, 2003
Messages
15
Re: Slow speed needles 115 hp 1970

Thanks again my friends!<br /><br />Of couse...Locktite! And i get the hint of removing it before i apply a propane torch to the fuel system...:^><br /><br />(i DO need that kind of guidance, i'm just a theorethical physicist!)<br /><br />37.50 a piece! Happy i didn't try harder when trying to open them, i almost broke them off.<br /><br />I will try the heating method<br /><br />Thanks for your patience.<br /><br />/Micael
 
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