25hp 2 stroke carb problems

Unclekoolaid1

Recruit
Joined
Oct 28, 2011
Messages
2
My motor has just started having problems. Its a 2002 2 stroke 25hp Mercury. CARB: (20/25/JET 20 SEAPRO/MARATHON 15XD SUPER 15/JET20) (2-STROKE)

When starting you have to pull the choke in and out multiple times and then pull start. Once it is started it runs rich but then sputters and kills after a few seconds. The way i stop this is when it sounds like it is killing i pull the choke in and out while running and once you put the motor in gear it will run perfect for miles without sputtering until you idle and the the process continues. I have changed spark plugs and soaked what looked to be like an already clean carb. I do notice that when you pull the choke it primes the carb and it looks a little leaky. Could it be my seals? I have a new gasket set and have yet to put it on. Looking for any other solutions while i have the carb apart.

By the way i take the boat out almost every weekend and i have seen fuel run through the filter and the line.

Thanks,

Taylor
 

rivermouse

Senior Chief Petty Officer
Joined
Jun 16, 2011
Messages
661
Re: 25hp 2 stroke carb problems

Soaking you know is not the same as taking the carb apart and cleaning it completely. Try some sea foam in the fuel and if that doesn't help I would clean/rebuild the carb.. A weak fuel pump can cause this also but the first step I would think is to be sure its not the carb. Be sure the carb tightens up snug using a good gasket when you put it back on.
 

Unclekoolaid1

Recruit
Joined
Oct 28, 2011
Messages
2
Re: 25hp 2 stroke carb problems

Sorry, What I actually meant was that the whole carb was taken apart and all rubber pieces set aside and all the metal parts soaked in a can of carb cleaner. I then put it back together and it started somewhat better but didnt take it long for the same problem to come back. Is it possible that the diaphragm is not sealing the mechanaical pump because of a bad gasket? I will try to put the gasket set this weekend (http://ecx.images-amazon.com/images/I/41TL8grbhWL._SS500_.jpg) that I ordered a couple of weeks ago. I did check the needle valve as well and it was very clean.

Thanks
 

Mi duckdown

Commander
Joined
Apr 14, 2007
Messages
2,575
Re: 25hp 2 stroke carb problems

Never been a fan of taking a carb apart and cleaning, without installing a new gasket kit. Doesn't make sense to ME, to go thru all the trouble without a kit.
When doing so I also use compressed air and I run Like 25 lb mono fishing line thru every orifice on the carb, just make sure everything is clear. Hope that helps.
 
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