85 hp Force/ Dirty plugs

[ChalkBoy]

I have an '87 85 hp Force. Runs real well, but I noticed that the plugs seem to have ton of oily deposits on them after it has ran then sat. They all seem to have a uniform amount. The engine does run a smokey exhaust, I can't seem to locate the mixture screw on the carbs to adjust it, assuming it is the mixture.<br /><br />Any suggestions?

 

[JB]

Re: 85 hp Force/ Dirty plugs

Ahoy, Chalkboy. Are you running 50:1 mix of FRESH unleaded, alcohol free regular 87 octane gasoline and TC-W3 rated oil (preferrably Wal-Mart Super Tech, Quicksilver or similar premium)?<br /><br />If you are, you might run a compression check. <br /><br />I get an impression that Force engines: 1. carbon up faster than more modern designs, and 2. Need to be decarbonized more often.<br /><br />There are several ways to decarbonize. Most of them cost money, but all work.<br /><br />Back in the days of wound rope starters we wound em up to about 3000rpm and sprayed water into the carb in little spurts until the resulting smoke turned white (steam). More modern approaches use exotic petroleum distillates, but get the same result.<br /><br />This must be done on a schedule, before deposits become heavy and start blocking exhaust ports and sticking rings into the grooves, etc.<br /><br />Check with your local dealer on what product to use and how to use it.<br /><br />You Force-sperts out there. Except for nonsense about premium fuel, do you have anything to add?<br /><br />Red sky at night. . . <br />JB

 

[12Footer]

Re: 85 hp Force/ Dirty plugs

I could not have said it better,JB. I too, suspect Chlakboy is using an inferior 2cycle oil,too much oil, or stale gas/oil mix.<br />And Forces DO carbon-up quickly due to thier 1970's technology. I use "ValvTect(tm) Marine Motor Decarb" twice yearly,or about once every 60hours operation. This product comes in a airesol can,and you're suposed to use the entire contents.I rarely do that on such a small motor tho.<br />It is available in the megamall,or in any West Marine store. It is expensive,running 8bukz a can!!!! But the product werks.<br />Some folks use a fuel additive, with very good results. However, my 50HP Force doesn't like me monkeying with it's precious 87octane diet....It get's plum cantankerous with even Sta-Bil added to the fuel.<br />This is something I would also avoid on the fuel mixture end of things (any type of fuel additives).

 

[dmessy]

Re: 85 hp Force/ Dirty plugs

Look to your recirculation system for the problem. When your motor gets gummed up(and it will due to the design)these small orfices clog off resulting in fouled plugs and a rough idle. The older Forces use a drain pan type system to recirculate unspent fuel in the crankcase whereas the newer ones have check valves. Mix your oil/gas ratio exactly the same every time.<br />Good luck!!

 

[ChalkBoy]

Re: 85 hp Force/ Dirty plugs

Thanks for all of the responses. I have been using 93 octaine, with Penzoil Marine TC-W3 2-cycle mix. I also have ran just about 2 tanks of gas with Penzoil Marine fuel system treatment. I always use stabilizer. <br /><br />The engine does run with a thick exhaust. And my fuel consuption is about 3 miles to the gallon. ?? (@80-90% throttle)<br /><br />Thanks!

 

[ChalkBoy]

Re: 85 hp Force/ Dirty plugs

THE COMPRESSION IN THE CYLINDERS IS FINE. 135 IN EACH. 125-145 IN NORMAL FOR THAT YEAR ACCORDING TO THE MANUAL.<br /><br />Thanks!

 

[sony2001]

Re: 85 hp Force/ Dirty plugs

ChalkBoy what plugs are you using?

 

[ChalkBoy]

Re: 85 hp Force/ Dirty plugs

Champion UL18V, off the top of my head I think that is the number. Anyway, I put in exactly what the manual called for. Torqued them down to 12 ftlbs...