84 Chrysler Sea King 9.9 Throttle Problem

[84seaking]

I just purchased a 9.9 hp 84' chrysler sea king, when i run it i can turn the throttle all the way up and it will run good for a minute then on its own drop back down to about half throttle . I changed the plugs, it idles good, I want full power!! I ran a little sea foam (about a gallon of gas and sea foam mix) through it and it seems to be running better but still not top notch, an outboard man told me that if i run it for a couple more gallons through it, that the sea foam will clear it up all the way. Is the jet clogged? If so, how do i clean? Keep running sea foam? never done this before. Thanks in adavance

 

[roscoe]

Re: 84 Chrysler Sea King 9.9 Throttle Problem

Is the primer bulb getting sucked flat?

Sounds like the carb is using up all the fuel in the carb bowl, and it is not refilling as it should. It could be several fuel system related items, but most likely the carb needs to be disassembled and thoroughly cleaned, and the float needs to be adjusted.

Take it off and disassemble.
Let it soak overnight, and give it a good cleaning the next day.

The Seafoam is an excellent fuel system cleaner and maintainer, but can't remove chunks of foreign debris like sand.

 

[84seaking]

Re: 84 Chrysler Sea King 9.9 Throttle Problem

thanks roscoe, the primer bulb isn't getting sucked flat, i've taken the carb off, it appears to just be one large piece except for the float which can be taken off. I've never cleaned a carb for an outboard, is there a specific technique? Thanks again

 

[eurolarva]

Re: 84 Chrysler Sea King 9.9 Throttle Problem

You will want to concentrate on the needle valve and the seat. Also it would not hurt to verify the holes on the main jet are open and clean. It sounds like the needle is sticking closed and then more fuel can not go into the float bowl. The low RPMs would be from gas still getting into the idle circuits. Does this look like your carb

CLICK HERE

If so Item 21 mercury part number F10101 is what you will want to order. That kit should include the needle and a new seat and cost is $14.12 and is called KIT, VALVE SEAT ASSEMBLY

Another problem you could be having is that the float has a hole in it and it is no longer a float but a sink. If that is the case you either will have to solder it or buy a new one.

 

[84seaking]

Re: 84 Chrysler Sea King 9.9 Throttle Problem

Thanks for the advice! I'm deinitely going to try it, will update on how things go, thanks again