Plugs fouling

MM2SS

Cadet
Joined
Oct 9, 2010
Messages
17
1201X90A Force outboard. Yesterday I had to pull my plugs twice and clean them just to start the motor. I have always thought that the motor was unusally wet around the carbs. Tilt the motor and it drips alot, but this may be the bowl emtying out through the main nozzle. If I choke it with the carb covers off gas will drip out of the carbs. Today I set the floats at 1/8th of an inch. They were set level with the carb body and I believe that to be wrong. As I'm reading the manual I understand it to say that they should be set at 3/16". I went at an 1/8" to see if there was a change. I ordered new needles today but won't see them for a week or so. Even with the resetting of the floats when the engine runs at around 1500 rpms the plugs are still wet. Very wet, a drop of gas on each one. It's 20 years old and I'm sure a lot of home handymen l have had their hands on it so it's possible that the jets have been changed. In fact the cowl says 125 which is what the boat came with new in 1989. It appears that the powerhead has been changed. The carb numbers coincide with the 120. Top end? This thing screams. Bayliner Trophy 1903 will occasionally hit 46 MPH. Low end could be better. Any thoughts? Thanks.
 

TwoFish

Petty Officer 1st Class
Joined
Aug 7, 2010
Messages
373
Re: Plugs fouling

There shouldn't be petrol dripping from you carbs. Sounds a bit dangerous.:eek:

Have the carbs been serviced lately? New needle & seat may help but could need new gasket set.

This site has a good write up on cleaning carbs in this section
http://forums.iboats.com/forumdisplay.php?f=31.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,074
Re: Plugs fouling

Excess gas could be the needle/seat.Or it could be the fuel pump diaphram. Or the check valves.Ethanol is bad for these motors.See my signature.J
 

MM2SS

Cadet
Joined
Oct 9, 2010
Messages
17
Re: Plugs fouling

Thanks for your responses. Seats are machined into the carb body and not replacable, new needles are on the way. What check valves are you referring to?
Do these fuel pumps have an overflow line that could be plugged? As I've already said, I've reset the floats so today, I'll put in new plugs and take it out and see how it runs in actual use. The boat needs gas, so today I'll try a different brand. Thanks again.
 

bman1bpm

Chief Petty Officer
Joined
Jul 19, 2004
Messages
450
Re: Plugs fouling

Its probably a needle/seat problem, or float level. I had to replace one of my carbs with one from a nother motor because the seat was bad and it would constantly flood
 

MM2SS

Cadet
Joined
Oct 9, 2010
Messages
17
Re: Plugs fouling

Thanks for all of your answers. It seems that the float level was a major factor here. The plugs look much better and no gas dripping at full tilt. I'm still not at the recommended 3/16 inch setting. When the new needles arrive I'll change the float level to the 3/16 setting. I even had to back out my idle screws just to keep it running without the choke. I am doing the Seafoam decarb right now, Ran it yesterday for a while (about 1/2 gal). Sprayed and soaked all night, will fire it up this morning and run the other 1/2 gal through it. Seems to idle better already. You guys weren't kidding abut the smoke, WOW!
 

j_k_bisson

Lieutenant Junior Grade
Joined
Oct 6, 2010
Messages
1,082
Re: Plugs fouling

I have a 1991 120 force and had the same issue. Found out the the recirculation screens where plugs. Leaving the excess gas in the cylinders. You will definately want to pull the plate off and clean the screens. As these can lead to other major issues.

The recirculation system take all the excess un burnt gas from the cylinder and uses it in the next cycle in the next cylinder. When I checked mine they where completely blocked. A like carb cleaner and they are perfectly clean. I was able to take the plates off and clean them without destroying the gaskets. When I did this the motor definately ran much much better.

I would not lean out the carbs though. If everything is set properly then it should not have this issue.

Jeff
 
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