Force 85 - Can't adjust fuel mixture

[Mark9740]

I have a early 80's model (could never find the serial #) Force 85. Using the manual I attempted to adjust the fuel mixture since the plugs are continually being fouled. The problem is that I can't seem to locate any adjustment screws on any of the 3 carbs. Are there some models out there that can't be adjusted. I welcome any suggestions. Thanks.

 

[foodfisher]

Re: Force 85 - Can't adjust fuel mixture

Fuel mixture (gas/oil)is done in the tank. No other adjustment other than quanity of fuel to the air that goes into the cylinder. Recommended starting position is 1 - 1 1/4 turns out. No less than 7/8 turn. Fine tune from there per manual instructions or you can find the instructions here using the search function. The screws on my '86 125hp are clearly visible with a spring on them. Sorry if I wasted your time.

 

[raekmike]

Re: Force 85 - Can't adjust fuel mixture

Check and double check what spark plugs your supposed to be using. Sounds like they might be the wrong ones. Make sure your using 50:1 ratio only
I use champion UL18V on my 1985 85hp

 

[john from md]

Re: Force 85 - Can't adjust fuel mixture

These engines were meant to be run most of their life at WOT. The engine is most efficient at WOT. If you idle long, do alot of start stop or ride around at less than WOT, the surface gap plugs will foul. Just clean them periodically and you will be fine.

Your mixture screws for the carbs are behind the intake cover. you can go through the little hole on the front.

John

 

[Frank Acampora]

Re: Force 85 - Can't adjust fuel mixture

Fouled plugs are a way of life with these outboards. Adjusting the idle mixture will do almost nothing to alleviate the problem and may, in fact, most certainly will damage the engine. Mess with the idle mixture and melt one or more pistons, and don't come crying to me--you did it to yourself.

Satisfy yourself with cleaning the plugs periodically; if you are using L20V, UL18V, or the equivalent surface gap plug, they can be cleaned ad infinitum. That's Latin, you know. It means indefinitely or, as Buzz Lightyear would say: "To infinity and beyond."

As I said a number of times before: The carbs stick out there like women's breasts. ALL men feel a need to play with them. Mess with them when you don't know what you are doing and you will most surely get into trouble.

 

[Mark9740]

Re: Force 85 - Can't adjust fuel mixture

Thanks one and all for the feedback. I just got back home from vacation to start tinkering with it. I appreciate the words of wisdom (and experience).

 

[further]

Re: Force 85 - Can't adjust fuel mixture

Whole heartedly agree with Frank - DO NOT MESS WITH THE CARBS if you don't know what you are doing. As i did and now have all kinds of issues.

 

[sho3boater]

Re: Force 85 - Can't adjust fuel mixture

I just put it in gear on the water, in the middle of a quiet lake, and turned each idle jet in until the idle missed then back out a little. I did all three like that and did it over maybe three or four times. This was as lean as I could get it because they stink so bad trolling. Then I opened each just a hair, like less than 1/8 turn. I have run it since I think '03 like that, it had new plugs at the time and they are champion but I forget the number. They are still in it, but I don't put many hours on it. Thing is a tank, always starts right up in the spring and never had a problem with it.

I've done a lot of old motors this way, it is proper to set idle under load and that would be trolling with an outboard at idle. Most of them you need to turn out more though, so they don't kill when you put them in gear depending on how low they drop when you shift...and some will kill repeatedly when cold if you don't add a quarter turn or so. Even the weather would change the mix of a Merc I had, but nothing seems to bother this force. Even if I open the jets 2 turns it idles about the same. It never loads up but will miss a little when you take off after a long troll....long would be maybe a mile since I don't troll fishing with it.

I also had a clamp on digital tach and set the idle speed when I did the jets.

I suppose even though this is a diy type forum, if you are not familiar with engines then read up more about it. If you open them more and have it rich it will not hurt anything, just maybe foul plugs and load up after extended idle. If you run it too lean that could be bad. I would not turn them in far as a good smooth idle allows and leave it there, you must have it richer than that and turn them out some.

The reason I do it this way instead of X turns, is because once in a while a needle jet can get screwed up maybe because someone hard seats it. Then it may be different, in that case with a multiple carb engine it would not have the same mixtures. If I do it this way I know each carb is getting the same mixture to start with, then richen it up a little. It may come out to the same spot as a manual says and it often does.