OMC problem

86larson

Cadet
Joined
Jul 27, 2008
Messages
6
hey guys, well heres my problem, i bought an 86 larson citation 175 last year and ran great, this year the first time i took it out, it ran fine on full speed, but the second i put it on idle it staled and when i turned the key it start but whont take its gas and run rough, then the morning after it run perfectly like nuthing happend, its been 4 times now i got out on the water and always the same thing but it seem be run a lil better each times, a tune up as been done when i bought the boat, i clean the carb and today when it staled again i put more liquild carb cleaner derectly in the carb and it look like i was runing a diesel. black smoke came out of the exaust, so guys help me out i have no more idea what to test, i was thinking maybe the coil is dyeing on me nyways let me know what u think it could be. thnx in advance
 

Gary H NC

Fleet Admiral
Joined
Dec 1, 2005
Messages
8,972
Re: OMC problem

Sounds like a fuel problem.Pouring carb cleaner down it does nothing to clean the inside of the carb.
Its possible the fuel filter is sucking up crud or the pick up tube in the gas tank is getting clogged.
Start with fuel filter change,and the water separator filter if it has one.
The carb most likely needs a rebuild too.
The filters and the pick up tube in the tank would be my starting point.
 

86larson

Cadet
Joined
Jul 27, 2008
Messages
6
Re: OMC problem

i already change the fuel filter but i will look for the pick tube thnx
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC problem

There is a fuel filter in the fitting that goes in the carb. maybe one in the fuel pump.

The anti-syphon valve may be sticking.

Vent might be clogged.

Do a pressure check on the fuel pump.
 

86larson

Cadet
Joined
Jul 27, 2008
Messages
6
Re: OMC problem

i change both filters and were would be the valve in the fuel system?? and thnx this realy helps!!
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC problem

The 90 degree turn fitting on top of the tank where the fuel line hooks into. Fuel pickup is connected to it.
 

86larson

Cadet
Joined
Jul 27, 2008
Messages
6
Re: OMC problem

and is there a special way to clean the valve, or just brake clean or something like that???
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC problem

It's a ball type check valve works one way blow thru it. Wouldn't hurt to shoot some carb cleaner thru it.
 

86larson

Cadet
Joined
Jul 27, 2008
Messages
6
Re: OMC problem

OK and do u have an idea why my engine would get carbonized realy fas like i does??
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC problem

You know what run the boat in the water with a external tank. That is after you clean the filter by the carb and fuel pump. You have a water separator?

Take the fuel hose off the tank and connect it to the external tank.
 

86larson

Cadet
Joined
Jul 27, 2008
Messages
6
Re: OMC problem

i dont have the water separator bu i will try the extenal tank. and run with 91 octane. thnx man your realy a good help
 
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