15 hp Merc won't start

hall0340

Cadet
Joined
Jul 27, 2004
Messages
6
1999 15 HP Merc manual start tiller handle. Carb was leaking gas so I rebuilt it figuring it was the needle. Also changed plugs. Went to tune it today and couldn't get it going. It pulls fine and will sputter for 2-3 seconds like it is going to start, but then dies out. Gas is new, correctly mixed, fuel line and bulb are new. I backed the low speed idle screw out the recommended 1-2 turns and made many adjustments with it to no avail. Idle speed knob position doesn't have any effect on this either, but pulling the choke will kill it right away. After 5 pulls or so in rapid succession I can hear a high pitched sound like compressed air escaping from somewhere. Any thoughts?
 

Mod2

Senior Chief Petty Officer
Joined
Jun 19, 2003
Messages
713
Re: 15 hp Merc won't start

Hello Matt and welcome to iboats forums. I'm gonna move your post over to Mercury and Mariner Repair forum. You'll do better over there.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 15 hp Merc won't start

Sounds like the float level is too high, Matt.<br /><br />Did you use a Manual when you set it up?
 

hall0340

Cadet
Joined
Jul 27, 2004
Messages
6
Re: 15 hp Merc won't start

I used a Selco manual for the rebuild, and tried to get the float at the correct level. It was difficult to get an accurate measurement though (they list it as 1 inch from bottom of float to top of post). I'll try bending the spring down a little. Thanks for the help.
 

hall0340

Cadet
Joined
Jul 27, 2004
Messages
6
Re: 15 hp Merc won't start

Readusted the float and it started right up. Thanks! However, now it runs great in neutral with 1 or 2 other problems: 1) there is a clicking noise that is related to throttle speed--increase in throttle=faster clicking. Sounds kind of what I remember a thrown rod sounding like in my old car. 2) It bogs and dies when I try to accelerate. Runs fine in forward or reverse at very low throttle. With some finesse and the choke I can get it wide open, then push the choke back in, and it's fine...until I go back to low throttle and try to accelerate again and it bogs and dies. Tried richening the mix with no luck. I actually have a second engine, 1999 15 hp merc electric start, that I just rebuilt the carb on as well, and it is having the same problem minus the clicking.<br /><br />I don't have a timing light or tachometer to get more information...do I need to get these? Thanks
 
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