Mariner 15 2 stroke

[Robherbert]

Hi was wondering if someone could help. I have a 1996 Mariner 15hp 2 stroke which runs almost like its 4 stroking when revved up. Probably running a bit rich.
I can find a mixture screw on the front of the carb above the air intake for the slow idle mixture but can't find one for the fast idle. Any advise would be very appreciated thanks Rob

 

[flyingscott]

There is no high speed adjustment on that carb it has a fixed jet. When was the carb serviced last? Are you revving it up in neutral or in gear on the boat or on muffs?

 

[Robherbert]

Revving it in neutral in a bin of water. Don't know when the carb was last serviced only had the engine a month or so. Engine seems the lag a bit when on the boat only really at full throttle

 

[racerone]

Most motor can not go full throttle in nuetral.----------------I would check for spark on both leads as it sounds like it is running on one cylinder !

 

[Robherbert]

I wasn't running on full throttle. It's not a full on miss its just not buzzing like a 2 strike should. Have ordered new plugs so will try them thanks for the reply. Think I'm going to do a carb clean as well

 

[flyingscott]

You need an open air spark checker to correctly check spark. You need a full rebuild kit for that carb do not just take it apart and clean it. The kit must have the primer and fuel pump diphragm assemblies.

 

[Robherbert]

Don't suppose you'd know what carb it is?

 

[flyingscott]

You need the serial # to look up parts. Same kit for a lot of years.

 

[Robherbert]

Thanks for all your help