adjusting carb

weasel

Cadet
Joined
May 3, 2002
Messages
13
Just rebuilt the carb on my Mariner(1960) 9.8 as per your wonderful help. However it is idling rough and the insturctions say to adjust the idle adj screw. How do you do this with it running. Can you take the cover off while it is running(Safely??). Or is there some way to start it with the cover off?? Thanks in advance for you time and help.
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: adjusting carb

Well, the cover is there for to protect the engine from the elements, and to protect you from moving parts. But in order to adjust the carb, you will need a pilot, and the cover off,underway, at a fast idle.This isn't absolutely nescessary, but will provide the best results.<br />Start by getting the engine to run,on the muffs in the driveway.<br />by setting the idle mixture screw 1 turn out. Be carefull when turning this screw all the way in (which you must do to know where 1 turn out is), because you can easily damage the needle or the seat. You'll want to screw it in just until it makes contact.Do not tighten it down.<br />Now, clockwise 1 turn, or until you can get the engine running.Adjust counter clockwise 1/8 turn at a time.Wait approx 10-20 seconds before turning it more. The engine at some point will run smooth...Keep adjusting out in 1/8 turn incraments,until it just starts to run rough. now do the same thing turning it in 1/8 trun at a time,past where it runs smooth,until it runs rough again. Then back out to midway between the two rough-running points.<br />You may be done, at this time, but you won't know until u have a load on the engine,fast idle,underway. But the process is the same as described above. There is "the setting" in the manual, and there is the real-world setting, at your altitude, and carb/compression/vacuum realities...No two are the same,even outta the box.
 

weasel

Cadet
Joined
May 3, 2002
Messages
13
Re: adjusting carb

Hey, 12-Footer thanks for the fast reply,as I recall it was your excellant help that saved me last time, I'm still a little confused though. What is a pilot? and , do I just remove the cover after it is running or is there some way to start it with the cover off??
 
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